second report on the law of treaties, by sir humphrey ...rebus sic stantibus, are controversial and...

Document:- A/CN.4/156 and Add.1-3

Second report on the law of treaties, by Sir Humphrey Waldock, Special Rapporteur

Topic: Law of Treaties

Extract from the Yearbook of the International Law Commission:- 1963 , vol. II

Downloaded from the web site of the International Law Commission (http://www.un.org/law/ilc/index.htm)

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36 Yearbook of the International Law Commission, Vol. II

their intention in the part of the original proposal relatingto the legal effects of the instruments of acceptancedeposited.

36. Several representatives were against any restric-tion of the principle of universality by reserving theprocedure to be followed to specific categories of States,while excluding others. It was pointed out that the useof the term " all States " in the subsequent revision ofthe draft resolution [A/C.6/L.504/Rev.2] would affirmthe principle of universality and would raise no difficul-ties for anyone—the draft providing for the expressconsent of the parties to the convention — in the matterof the legal effects of the instruments of acceptancedeposited. Every contracting State would thus be com-pletely free to establish, or not to establish, treaty rela-tions with any State wishing to accede to the conventionor conventions in questions. This interpretation was,however, rejected by one of the co-sponsors of the draftresolution.

37. The relationship between this proposal [A/C.6/L.504/Rev.2] and the question of the succession ofStates aroused the concern of a number of representa-tives. In their view, the determination of the States nowparties to the conventions in question involves a problemof the succession of States, since new States have beenable to accede to old conventions under agreementsmade on their behalf by the States which formerlyrepresented them in the international field. It was alsopointed out that the proposal was meant to apply tosiuations in which there were no problems of successionof States.

38. With regard to the nature of the acceptance,some representatives felt that it should be made clearthat such acceptances could not be accompanied by" reservations", since that was a practice which hadbeen introduced since the conclusion of conventionsunder the auspices of the League of Nations.

39. Finally, most representatives considered that amore thorough study was needed of the possible implica-

tions of the question. A number of representativessubmitted a draft resolution (A/C.6/L.508), which wassubsequently revised (A/C.6/L.508/Rev.l), requestingthe International Law Commission to study the problemfurther — with special reference to the debate in theGeneral Assembly — and to inform the General Assem-bly of the result of its studies in the report on the workof its fifteenth session, and requesting the inclusion of thequestion on the agenda of the next session of the GeneralAssembly. Although some representatives consideredthat the problem involved in the participation of newStates in treaties concluded under the auspices of theLeague of Nations would be more appropriately resolvedby the General Assembly and had doubts regarding thesuitability of referring the question to the InternationalLaw Commission, the Sixth Committee adopted theproposal contained in the draft resolution (A/C.6/L.508/Rev.l).

157. On the recommendation of the Sixth Com-mittee, the General Assembly adopted, at its 1171stmeeting, held on 20 November 1962, resolution 1766(XVII) on the question of extended participation ingeneral multilateral treaties concluded under the auspicesof the League of Nations. The text of this resolution isreproduced below:

The General Assembly,Taking note of paragraph 10 of the commentary to articles 8

and 9 of the draft articles on the law of treaties contained in thereport of the International Law Commission covering the workof its fourteenth session,

Desiring to give further consideration to this question,1. Requests the International Law Commission to study

further the question of extended participation in general multi-lateral treaties concluded under the auspices of the League ofNations, giving due consideration to the views expressed duringthe discussions at the seventeenth session of the General Assem-bly, and to include the results of the study in the report of theCommission covering the work of its fifteenth session;

2. Decides to place on the provisional agenda of its eigh-teenth session an item entitled " Question of extended parti-cipation in general multilateral treaties concluded under theauspices of the League of Nations ".

DOCUMENT A/CN.4/156 and Add.1-3

Second report on the law of treaties, by Sir Humphrey Waldock, Special Rapporteur

[Original: English][20 March, 10 April,

30 April and 5 June 1963]

TABLE OF CONTENTS

PageINTRODUCTION

A. The basis of the present report 38

B. The scope and arrangement of the present group of draft articles 38

THE ESSENTIAL VALIDITY, DURATION AND TERMINATION OF TREATIES

Section I — General provisions

Article 1 — Definitions 38Commentary 39

Article 2 — The presumption in favour of the validity of a treaty 39Commentary 39

Article 3 — Procedural restrictions on the exercise of a right to avoid or denounce a treaty . . 39Commentary 39

Law of Treaties 37

TABLE OF CONTENTS (continued)

PageArticle 4 — Loss of a right to avoid or denounce a t reaty th rough waiver or preclusion . . . . 39

C o m m e n t a r y 40

Section II — Principles governing the essential validity of treatiesArticle 5 — Constitutional limitations on the treaty-making power 41

Commentary 41Article 6 — Particular restrictions upon the authority of representatives 46

Commentary 46Article 7 — Fraud inducing consent to a treaty 47

Commentary 47Article 8 — Mutual error respecting the substance of a treaty 48Article 9 — Error by one party only respecting the substance of a treaty 48

Commentary to articles 8 and 9 48Commentary to article 8 49Commentary to article 9 49

Article 10 — Errors in expression of the agreement 50Commentary 50

Article 11 — Personal coercion of representatives of States or of members of State organs . . 50Commentary 50

Article 12 — Consent to a treaty procured by the illegal use or threat of force 51Commentary 51

Article 13 — Treaties void for illegality 52Commentary 52

Article 14 — Conflict with a prior treaty 53Commentary 54

Section HI— The duration, termination and obsolescence of treaties

Article 15—Treaties containing provisions regarding their duration or termination 61Commentary 62

Article 16 — Treaties expressed to be of perpetual duration 63Commentary 63

Article 17 — Treaties containing no provisions regarding their duration or termination 64Commentary 64

Article 18 — Termination of a treaty by subsequent agreement 70Commentary 70

Article 19 — Implied termination by entering into a subsequent treaty 71Commentary 72

Article 20 — Termination or suspension of a treaty following upon its breach 72Commentary 73

Article 21 — Dissolution of a treaty in consequence of a supervening impossibility or illegalityof performance 77Commentary 78

Article 22 — The doctrine of rebus sic stantibus 79Commentary 80

Section IV — Procedure for annulling, denouncing, terminating, withdrawing from or suspendinga treaty and the severance of treaty provisions

Article 23 —Authority to annul, denounce, terminate, withdraw from or suspend a treaty . . . . 85Commentary 85

Article 24 — Termination, withdrawal or suspension under a right expressed or implied in thetreaty 86Commentary 86

Article 25 — Annulment, denunciation, termination or suspension of treaty obligations undera right arising by operation of law 86Commentary 87

Article 26 — Severance of treaties 90Commentary 90

Section V — Legal effects of the nullity, avoidance of avoidance or termination of a treaty

Article 27 — Legal effects of the nullity or avoidance of a treaty 93Commentary 93

Article 28 — Legal effects of the termination of a treaty 94Commentary 94


Introduction

A. The basis of the present report

1. At its fourteenth session the Commission provi-sionally adopted part I of its draft articles on the lawof treaties, consisting of twenty-nine articles on theconclusion, entry into force and registration of treaties(A/5209, chapter II, paragraph 23). At the same timethe Commission decided, in accordance with articles 16and 21 of its Statute, to transmit this draft, throughthe Secretary-General, to Governments for their observa-tions {ibid., paragraph 19). The Commission furtherdecided to continue its study of the law of treaties atits next session, to give the topic priority and to takeup at that session the questions of the validity and dura-tion of treaties {ibid., chapter III, paragraph 32 andchapter IV, paragraph 65). The Special Rapporteuraccordingly now submits to the Commission his secondreport, covering these two aspects of the law of treaties.

2. Both the " validity " and the *' duration " of treatieshave been the subject of reports by previous SpecialRapporteurs. " Validity " was dealt with by Sir H. Lau-terpacht in articles 10-16 of his first report on the lawof treaties (A/CN.4/63); and in his revision ofarticle 16 in his second report (A/CN.4/87); andby Sir G. Fitzmaurice in his third report (A/CN.4/115)." Duration" was not covered by Sir H. Lauterpacht ineither of his two reports, but was dealt with at lengthin Sir G. Fitzmaurice's second report (A/CN.4/107).Owing to the pressure of other work none of thesereports has been examined by the Commission; but thepresent Special Rapporteur has naturally made the fullestuse of them in preparing his own report.

B. The scope and arrangement of the present groupof draft articles

3. The present group of draft articles covers the broadtopics of {a) " essential validity " and {b) " duration ".

" Essential validity " has been interpreted as extendingto all questions of the possible invalidity of treaties,including the effect of constitutional limitations uponthe powers of State agents, but not to limitations uponthe treaty-making capacity of States themselves. The latterquestion has contacts with the other grounds of invali-dity, and is noticed in one or two places in the report,but capacity of parties has not been regarded as withinthe scope of the present articles. " Capacity to concludetreaties " was dealt with by the Commission at itsfourteenth session in drafting article 3 of part I of thedraft articles in the law of treaties; and, having regardto the position taken by the Commission concerning" capacity " in article 3, the Special Rapporteur hasexcluded the question of the possible " invalidity " oftreaties for lack of capacity in one of the parties fromthe present group of articles. Nor has " impossibility ofperformance " been dealt with as a distinct ground of" invalidity ", because impossibility of performance asa ground of invalidity ab initio, as distinct from super-vening impossibility as a ground of termination oftreaties, is really covered by error vitiating consent.

" Duration " has been interpreted as extending to theduration, termination, suspension and obsolescence oftreaties, but not to their revision. The topic of revision,

though related in some ways to those of the terminationand obsolescence of treaties, relates to a different legalprocess raising complicated problems of its own, andmust therefore be left for separate treatment. Statesuccession is another topic which has points of contactwith termination and obsolescence of treaties; but hereagain, State succession is really a special process whichthe Commission has for that reason already decided totake up as a separate topic.4. The present group of articles deals with a numberof grounds upon which a State may claim that a treatyinto which it has entered is not binding upon it. Someof these grounds, like the effect of constitutional limita-tions, conflict with prior treaties and the doctrine ofrebus sic stantibus, are controversial and in addition givescope for subjective determinations by the interestedStates. These and other grounds (e.g. the right toterminate a treaty which arises form a breach by theother party), because they involve the risk of unilateraldeterminations by the interested States, represent acertain threat to the security of treaties. That being so,the procedural aspects of avoiding or denouncing atreaty assume particular importance and are dealt within a separate section of the draft.5. At its fourteenth session the Commission decided,provisionally and for the purpose of facilitating thework of drafting, to follow the method adopted for thelaw of the sea and to prepare a " series of self-containedthough closely related groups of draft articles " (A/5209, chapter II, paragraph 18). Accordingly the presentgroup of articles on the " essential validity, duration andtermination of treaties " has been constructed in theform of a separate draft convention, with the title" Part II ". The articles comprised in it have beenarranged in five sections: (i) general provisions, (ii) prin-ciples governing the essential validity of treaties,(iii) principles governing the duration, termination, sus-pension and obsolescence of treaties, (iv) proceduralrequirements in regard to the avoidance, denunciationor suspension of a treaty; and (v) legal consequencesof avoidance, denunciation or suspension of a treaty.In this part, as in part I, the Special Rapporteur hassought to codify the modern rules of international lawon the topics with which the report deals. On somequestions, however, the articles formulated in the reportcontain elements of progressive development as well asof codification of the law.

The Essential Validity,Duration and Termination of Treaties

SECTION I — GENERAL PROVISIONS

Article 1—Definitions

1. The expression " part I " as used in the presentarticles means part I of the draft articles on the law oftreaties.2. The expressions defined in article 1 of part I shallhave the same meanings in the present part as areassigned to them in that article.3. For the purposes of the present articles, the follow-ing expressions shall have the meanings hereunderassigned to them:

Law of Treaties 39

(a) "' Enter into " a treaty means to establish on theinternational plane the State's consent to be bound bya treaty by one of the procedures provided for in part I.

(b) " Denounce " a treaty means to declare that aState will no longer consider itself bound by the treatyeither as from the date of the declaration or from someother date.

(c) " Jus cogens " means a peremptory norm ofgeneral international law from which no derogation ispermitted except upon a ground specifically sanctionedby general international law, and which may be modifiedor annulled only by a subsequent norm of general inter-national law.

Commentary1. The question whether the various parts of the lawof treaties are to be amalgamated in a single draftconvention or are to remain separate, self-containedparts is for decision at a later date. But in any eventit will be desirable that the use of technical terms shouldbe uniform in the different parts. It may be that ulti-mately it will be found more convenient to place allthe definitions for the law of treaties in a single article.Meanwhile, however, it seems appropriate to providefor the application in the present part of the definitionscontained in part I. This is done in paragraph 2 of thearticle, while paragraph 1, for convenience of drafting,specifies that the term part I will always be used todesignate the articles on the " Conclusion, entry intoforce and registration of treaties " dealt with by theCommission at its fourteenth session.

2. Paragraph 3 adds three new definitions for the pur-poses of the present part. Those in sub-paragraphs (a)and (b) do not appear to require comment; the defini-tion of the two terms in question is thought useful inorder to avoid circumlocution in other articles. Theterm " jus cogens " is defined in sub-paragraph (c) forthe purposes of article 13. It is a term which is wellenough understood, but it is not so easily defined withprecision. The essence of the concept, it is thought, isthat a jus cogens rule is a rule embodying a norm ofgeneral international law from which no derogation ispermitted and which can only be modified or set asideby the creation of a further norm of general internationallaw. On the other hand, it seems advisable to qualifythe phrase " from which no derogation is permitted "by reference to grounds " specifically sanctioned byinternational law ", in order to allow for such possiblegrounds as legitimate self-defence.

Article 2 — The presumption in favour of the validityof a treaty

Every treaty entered into and brought into force inaccordance with the provisions of part I shall be pre-sumed to be valid and binding upon the parties unlessit —(a) lacks essential validity under the rules set out in

section II of this part; or(b) has ceased to be in force under the rules set out in

section III of this part.

CommentaryThis part of the draft articles contains a series of

provisions which formulate grounds upon which a treatymay either be set aside as lacking essential validity or

denounced as no longer retaining its former validity.Accordingly, it seems desirable to emphasize in section Ithat the primary rule is that any treaty concluded andbrought into force in accordance with the rules set outin part I of the draft articles is presumed to be validand binding. In other words, the onus is upon a partywhich asserts that a regularly concluded treaty is notbinding upon it. Unilateral assertions of a right to avoidor denounce treaties on one or other of the groundscovered in this part, simply as a pretext to escape frominconvenient obligations, have always been a source ofinsecurity to treaties; and one of the most difficultproblems in this part is to formulate the grounds ofinvalidity in terms which do not open the door too wideto unilateral avoidance or denunciation of treaties. It istherefore thought important to underline in the presentarticle that the presumption is always in favour of thevalidity of a treaty concluded and brought into forceunder the procedures and rules laid down in part I.

Article 3 — Procedural restrictions on the exercise ofa right to avoid or denounce a treaty

A right to avoid or denounce a treaty arising underany of the provisions of sections II and III of this partshall be exercisable only in conformity with procedureslaid down in section IV.

CommentaryThe purpose of this article, as of article 2, is to

underline that the grounds for invalidating or terminatinga treaty set out in this part may not be lightly assertedand may not be employed simply as a pretext for escapingfrom an inconvenient treaty. These grounds for invali-dating or terminating a treaty, legitimate in themselves,do involve certain risks to the security of treaties owingto the possibility of a State's arbitrarily asserting theexistence of such a ground and constituting itself thejudge of the validity of its own assertion. Commentatorsupon this branch of the law of treaties have thereforenearly all sought to make the right to avoid or denouncea treaty dependent to some extent upon the fulfilment ofprocedural requirements. Delicate although the task isof formulating procedural requirements for the avoidanceor denunciation of treaties which have any prospectof being accepted at a diplomatic conference, thisapproach to the problem seems correct and necessary.Section IV contains the Special Rapporteur's proposalsfor these requirements; it seems desirable in the presentsection to draw attention at once to the fact that therights of avoidance and denunciation contained in thispart are linked to the procedural requirements in sec-tion IV.

Article 4 — Loss of a right to avoid or denouncea treaty through waiver or preclusion

A right to avoid or denounce a treaty arising underany of the provisions of sections II and III of this partshall not be exercisable if, after becoming aware of thefact creating such right, the State concerned —(a) shall have waived the right;(b) shall have accepted benefits or enforced obligations

under the treaty; or(c) shall otherwise, by its own acts or omissions, have

precluded itself from asserting, as against any other


party or parties, that the treaty lacks essentialvalidity or, as the case may be, that it is not still inforce.

Commentary

1. The principle of preclusion (estoppel) is a generalprinciple of law whose relevance in international lawis generally admitted and has been expressly recognizedby the International Court of Justice itself in two recentcases.1 Under this principle a party is not permitted totake up a legal position that is in contradiction withits own previous representations or conduct, whenanother party has been led to assume obligationstowards, or attribute rights to, the former party inreliance upon such representations or conduct.2 If insome legal systems, such as the common law systems,the application of the principle may to some extent bedependent upon technical rules,3 the foundation of theprinciple is essentially good faith and fair dealing, whichdemand that a party shall not be able to gain advantagefrom its own inconsistencies (allegans contraria nonaudiendus est).

2. Preclusion (estoppel) is a principle of general appli-cation, which is not confined to the law of treaties, stillless to this part of it.4 Nevertheless, it does have aparticular importance in this branch of internationallaw. As already mentioned in the two previous commen-taries, the grounds upon which treaties may be invali-dated under section II or terminated under section IIIinvolve certain risks of arbitrary avoidance or denun-ciation of treaties. Another risk is that a State, afterbecoming aware of an essential error in the conclusionof the treaty, of an excess of authority committed byits representative, of a breach by the other party etc.,may continue with the treaty as if nothing had happenedand only raise the matter at a much later date when itdesires for quite other reasons to put an end to itsobligations under the treaty. Indeed, it may seek in thisway to resuscitate an alleged ground of invalidity orof termination long after the event upon the basis ofarbitrary or controversial assertions of fact. The prin-ciple of preclusion, although it may not be able alto-gether to prevent the arbitrary assertion of claims toavoid or denounce treaties, does place a valuable limitupon the cases in which such claims can be assertedwith any appearance of legitimacy. Such indeed was therole played by the principle in the Temple case and inthe case of the Arbitral Award of the King of Spain.Accordingly, while appreciating the general characterof the principle, the Special Rapporteur suggests thatits particular operation in the sphere of the validity andtermination of treaties should be given express recogni-tion in this part. Moreover, although logically a casecould be made out for placing this article in a later

1 The Arbitral Award made by the King of Spain, I.C.J.,Reports, 1960, pp. 213-214; The Temple of Preah Vihear, I.C.J.Reports, 1962, pp. 23-32.

2 In Spanish systems of law the doctrine is known as " la doc-trina de los actos propios ".

3 See generally Canadian and Dominion Sugar Co. v. Cana-dian National (West Indies) Steamships Ltd. [1947] Law ReportsAppeal Cases, at p. 55.

4 See generally D. W. Bowett, British Yearbook of Internatio-nal Law, 1957, pp. 176-202; Bin Cheng, General Principles ofLaw, pp. 141-149; Judges Alfaro and Fitzmaurice in The Templeof Preah Vihear, l.CJ. Reports, 1962, pp. 39-51, 61-65.

section, there seems to be some advantage in includingit amongst the *' general provisions ".

3. " Waiver " has been included in this article because,although not identical with preclusion, it is closelyconnected with it; indeed, many cases of preclusion canalso be viewed as cases of implied waiver. Sub-para-graph (a), therefore, covers cases of express waiver ofa right to avoid a treaty for lack of essential validityor to terminate a treaty by denunciation for breach, etc.

4. It has not been thought necessary or appropriate toattempt an exhaustive definition of cases of preclusionin the present article, since the principle is a generalone also applicable outside the law of treaties. The mostobvious and common case in the law of treaties is likelyto be that where a State, notwithstanding its knowledgeof a ground of invalidity or of termination, invokes thetreaty either for the purpose of claiming rights or ofenforcing obligations. Accordingly this is specially men-tioned in sub-paragraph (b), while the general principleof preclusion is covered in sub-paragraph (c).

5. Sub-paragraphs (b) and (c) are based upon the pro-nouncements of the Court in the Temple case and in thecase of the Arbitral Award made by the King of Spain,which make it clear that preclusion may arise both fromacts and omissions. In the Temple case, which involved aclaim to set aside an agreement on the ground of error,the Court said:

" Even if there were any doubt as to Siam's accep-tance of the map in 1908, and hence of the frontierindicated thereon, the Court would consider, in thelight of the subsequent course of events, that Thailandis now precluded by her conduct from asserting thatshe did not accept it. She has, for fifty years, enjoyedsuch benefits as the Treaty of 1904 conferred on her,if only the benefit of a stable frontier. France, andthrough her Cambodia, relied on Thailand's accep-tance of the map. Since neither side can plead error, itis immaterial whether or not this reliance was basedon a belief that the map was correct. It is not nowopen to Thailand, while continuing to claim and enjoythe benefits of the settlement, to deny that she wasever a consenting party to it." 5

In the Arbitral Award case Nicaragua sought to set asidethe Award on three grounds, one of which was that thearbitration treaty providing for the setting up of theTribunal had expired before the designation of the Kingof Spain as Arbitrator. The Court, however, said:

" Nicaragua, by express declaration and by conduct,recognized the Award as valid and it is no longeropen to Nicaragua to go back upon that recognitionand to challenge the validity of the Award. Nicaragua'sfailure to raise any question with regard to the validityof the Award for several years after the full terms ofthe Award had become known to it further confirmsthe conclusion at which the Court has arrived." 6

While the formulation of sub-paragraphs (b) and (c) isderived from the Court's jurisprudence in these twocases, the two sub-paragraphs are intended, in combina-tion, to embrace the whole principle of preclusion.

5 The Temple of Preah Vihear, I.C.J. Reports, 1962, p. 32.6 The Arbitral Award made by the King of Spain, l.CJ.

Reports, I960, p. 213.

Law of Treaties 41

SECTION II — PRINCIPLES GOVERNING THE ESSENTIALVALIDITY OF TREATIES

Article 5 — Constitutional limitations on the treaty -making power

1. Whenever the constitution of a State —(a) prescribes that treaties, or particular classes of

treaties, shall not be entered into without their firsthaving been submitted to a particular organ of the Statefor confirmation or approval, or that they shall not bebinding upon the State or shall not have effect withinthe State's internal law unless previously ratified orapproved by a particular organ of the State, or

(b) contains any other provisions limiting either theexercise of the treaty-making power or the validity oftreaties under internal law, the effect of such provi-sions on the essential validity of treaties shall be deter-mined by reference to the rules contained in the subse-quent paragraphs of this article.2. Subject to paragraph 4, a State shall not be entitledto deny the validity in international law of the act of oneits representatives by which, in disregard of relevantprovisions of the constitution, the representative haspurported to enter into a treaty on its behalf, when —

(a) in the case of a treaty binding upon signatureunder articles 11 and 12 of part I, the treaty has beensigned by a representative competent under the rules laiddown in article 4 of part I to bind the State by his signa-ture;

(b) in other cases, an instrument of ratification, accep-tance, approval or accession has been exchanged ordeposited in accordance with the treaty and the instru-ment appears on its face to have been executed in properform by a representative of the State competent for thatpurpose under the rules laid down in article 4 of part I.3. In cases falling under paragraph 2 —

(a) if the treaty is already in force or is brought intoforce by the unconstitutional signature or other uncon-stitutional act of its organ, the State concerned may onlyretract its consent to be bound by the treaty with theagreement of the other party or parties to the treaty;

(b) if the treaty is not yet in force, the State concernedmay nevertheless retract the unconstitutional signatureor other unconstitutional act of its organ at any timebefore the treaty shall have come into force, upon givingnotice to the depositary or to the other party or partiesto the treaty.4. (a) Paragraphs 2 and 3 shall not apply if the otherinterested State or States or the depositary were in factaware at the time that the representative lacked constitu-tional authority to establish his State's consent to bebound by the treaty, or if his lack of constitutionalauthority to bind his State was in the particular cir-cumstances manifest to any representative of a foreignState dealing with the matter in good faith.

(b) In the cases mentioned in sub-paragraph (a), theState concerned shall be free to annul the signature ofits representative or to retract the instrument of ratifica-tion, acceptance, approval or accession exchanged ordeposited in its name at any time, provided that it hasnot —(i) subsequently ratified the unauthorized act of its

representative;(ii) so conducted itself as to bring the case within theprovisions of article 4 of this part.

Commentary1. Constitutional limitations affecting the exercise ofthe treaty-making power take various forms.7 Someconstitutions seek to preclude the executive from enteringinto treaties, or particular kinds of treaties, except withthe previous consent of a legislative organ; some providethat treaties shall not be effective as law within the Stateunless " approved " or confirmed in some manner by alegislative organ; others contain fundamental laws whichare not susceptible of alteration except by a special pro-cedure of constitutional amendment and which in thatway indirectly impose restrictions upon the power of theexecutive to conclude treaties. Legally, a distinction canbe drawn under internal law between those types ofprovision which place constitutional limits upon thepower of a government to enter into treaties and thosewhich merely limit the power of a government toenforce a treaty within the State's internal law withoutsome form of endorsement of the treaty by the legisla-ture. The former can be said to affect the actual powerof the executive to conclude a treaty, the latter merelythe power to implement a treaty when concluded. Poli-tically, however, the effect of the two types of provisionupon the exercise of the treaty-making power may not bevery different, since a responsible government will notknowingly commit the State to be bound by a treatyunless reasonably assured of being able to carry throughthe legislature any modifications of its municipal lawnecessary to enable it to perform its obligations underthe treaty. The question which arises under articles 4and 5 is how far, if at all, any of these constitutionallimitations may affect the validity under internationallaw of a consent to a treaty given by a State agent osten-sibly authorized to declare that consent; and on thisquestion opinion has been sharply divided.2. One group of writers 8 maintains that internationallaw leaves it to the internal law of each State to deter-mine the organs and procedures by which the will of aState to be bound by a treaty shall be formed andexpressed; and that constitutional laws governing theformation and expression of a State's consent to a treatyhave always to be taken into account in consideringwhether an international act of signature, ratification,acceptance, approval or accession is effective to bind theState. According to this doctrine, internal laws limitingthe power of State organs to enter into treaties are to beconsidered part of international law so as to avoid,or at least render voidable, any consent to a treatygiven on the international plane in disregard of aconstitutional limitation; the agent purporting to bindthe State in breach of the constitution is totally incom-petent in international as well as national law to expressits consent to the treaty. If this doctrine is accepted, itfollows that other States are not entitled to rely on theostensible authority to commit the State possessed by aHead of State, Prime Minister, Foreign Minister, etc.,under article 4 of part I; they are required to satisfy

7 See United Notions Legislative Series, Laws and Practicesconcerning the Conclusion of Treaties (ST7LEG/SER.B/3).

8 E.g. M. W. Schiicking, Annuaire de I'lnstitut de Droit Inter-national. 1930, p. 225; P. Chailley, La Nature Juridique desTraites Internationally: selon le Droit Contemporain, pp. 175 and215; S. B.Crandall, Treaties, their Making and Enforcement, pp.13-14; C. De Visscher, Bibliotheca Visseriana, vol. 2 (1924),p. 98.


themselves in each case that the provisions of the State'sconstitution are not infringed or take the risk of subse-quently finding the treaty void. The weakening of thesecurity of treaties which this doctrine entails is said bythose who advocate it to be outweighed by the need togive the support of international law to democratic prin-ciples in treaty-making.

3. The Commission's first Special Rapporteur on thelaw of treaties, Professor Brierly, took this view, and in1951 the Commission itself adopted an article basedupon it.9 Some members, however, were strongly criticalof the doctrine that constitutional limitations are incor-porated into international law, while Mr. Kerno, theAssistant Secretary-General, expressed misgivings asto the difficulties with which it might confront deposi-taries. During the discussion the Rapporteur said thatthe Commission's decision had been based more on thepractical consideration that States would not accept anyother rule than on legal principles.

4. A second group of writers,10 while basing themselveson the incorporation of constitutional limitations intointernational law, recognize that some qualification ofthat doctrine is essential if it is not to undermine thesecurity of treaties. According to this group, good faithrequires that only notorious constitutional limitationswith which other States can reasonably be expected toacquaint themselves should be taken into account. Onthis view, a State contesting the validity of a treaty onconstitutional grounds can only invoke those provisionsof the constitution which are notorious or could easilyhave been ascertained by inquiry. Moreover, somewriters in this group further maintain that a State whichinvokes the provisions of its constitution to annul itssignature, ratification, etc., of a treaty, is liable to com-pensate the other party which *' relied in good faith andwithout any fault of its own on the ostensible authority ofthe regular constitutional organs of the State 'V1 Theyalso hold that, by allowing an undue period of time toelapse before invoking the invalidity of a treaty or byasserting rights under the treaty, a State may precludeitself from contesting the binding force of its signature,ratification, etc.

5. The Commission's second Special Rapporteur onthe law of treaties, Sir H. Lauterpacht, belonged to thisgroup, and in article 11 of his first report12 proposed thefollowing set of rules to cover the question of constitu-tional limitations:

" 1 . A treaty is voidable, at the option of theparty concerned, if it has been entered in disregard ofthe limitations of its constitutional law and practice.

9 Article 2: " A treaty becomes binding in relation to a Stateby signature, ratification, accession or any other means ofexpressing the will of the State, in accordance with its constitu-tional law and practice through an organ competent for thatpurpose." (Yearbook of the International Law Commission,1951, vol. II, p. 73).

10 E. G. Lord McNair, Law of Treaties (1961), chapter III;Paul De Visscher, De la conclusion des traites internationaux(1943), p. 275; P. Guggenheim, Recueil des Cours de YAcade-mic de droit international, vol. 74 (1949), p. 236; J. MervynJones, Full Powers and Ratification (1946); pp. 154-155; Sir H.Lauterpacht, First Report on the Law of Treaties, Yearbook ofthe International Law Commission, 1953, vol. II, pp. 141-146.

11 Sir H. Lauterpacht, op. cit., p. 143; see also Lord McNair,op. cit., p. 77; Research in International Law, Harvard LawSchool, part Til, Law of Treaties, art. 21.

12 Sir H. Lauterpacht, op. cit., p. 141.

' ' 2 . A contracting party may be deemed, accord-ing to the circumstances of the case, to have waived itsright to assert the invalidity of a treaty concluded indisregard of constitutional limitations if for a pro-longed period it has failed to invoke the invalidity ofthe treaty or if it has acted upon or obtained anadvantage from it.

" 3 . In cases in which a treaty is held to be invalidon account of disregard of the constitutional limita-tions imposed by the law or practice of a contractingparty that party is responsible for any resultingdamage to the other contracting party which cannotproperly be held to have been affected with knowledgeof the constitutional limitation in question.

" 4. A party cannot invoke the invalidity of atreaty on the ground that it has been entered into indisregard of the constitutional limitations of the othercontracting party.

" 5 . A party asserting the invalidity of a treaty onaccount of any failure to comply with constitutionallimitations is bound, in case of disagreement, to submitthe substance of the dispute or the question of damageto the International Court of Justice or to any otherinternational tribunal agreed upon by the parties."

In putting forward these proposals Sir H. Lauterpachtmaintained that the practice of States and the bulk ofmodern writers support such a compromise between thefundamental principle of the nullity of acts done by Stateagents in excess of their constitutional authority and therequirements of good faith and of the security of treaties.The Commission itself did not have an opportunity todiscuss his proposals.6. A compromise solution based upon the initial hypo-thesis of the invalidity in international law of an uncon-stitutional signature, ratification, etc., of a treaty presentscertain logical and practical difficulties. If a constitu-tional limitation laid down in the internal law of a Stateis to be regarded as effective in international law tocurtail the authority of a Head of State or other Stateagent to declare the State's consent to a treaty, it may beasked upon what principle a " notorious " limitation iseffective for that purpose but a " non-notorious " one isnot. Under the State's internal law both kinds of limita-tion are legally effective to curtail the agent's authorityto enter into the treaty. Similarly, if the constitutionallimitation is effective in international law to deprive theState agent of any authority to commit the State withrespect to the treaty, it may not be easy to see uponwhat principle the State can be held internationallyresponsible in damages in respect of its agent's unautho-rized signature, ratification, etc., of the treaty. If theinitial signature, ratification, etc., of the treaty is notattributable to the State by reason of the lack of autho-rity, all subsequent acts of the State agents with respectto the same treaty would also logically seem not to beattributable to the State. It may be added that, if internalconstitutional provisions are to be regarded as incorpo-rated in international law, it is not obvious why theunconstitutionality of a treaty should be a matter whichcan only be invoked by the State whose constitution isthe cause of its invalidity, and not by the other parties tothe treaty.7. The practical difficulties are even more formidable,because the notion that a distinction can readily bemade between notorious and non-notorious constitu-

Law of Treaties 43

tional limitations is to a large extent an illusion. Admit-tedly, there now exist collections of the texts of Stateconstitutions and the United Nations has issued a volumeof v' Laws and Practices concerning the conclusion ofTreaties "13 based on information, supplied by a consi-derable number of States. Unfortunately, however, neitherthe texts of constitutions nor the information made avail-able by the United Nations are by any means sufficientto enable foreign States to appreciate with any degree ofcertainty whether or not a particular treaty falls within aconstitutional provision. Some provisions are capable ofsubjective interpretation, such as a requirement that" political " treaties or treaties of " special importance "should be submitted to the legislature; some constitutionsdo not make it clear on their face whether the limitationrefers to the power to conclude the treaty or to itseffectiveness within domestic law. But even when theconstitutional provisions are apparently uncomplicatedand precise, the superficial clarity and notoriety of thelimitations may be quite deceptive, as in the case of theUnited States Constitution. In the majority of caseswhere the constitution itself contains apparently strictand precise limitations, it has nevertheless been foundnecessary to admit a wide freedom for the executive toconclude treaties in simplified form without following thestrict procedures prescribed in the constitution; and thisuse of the treaty-making power is only reconciled withthe letter of the constitution either by a process of inter-pretation or by the development of political understand-ings. Furthermore, the constitutional practice in regardto treaties in simplified form tends to be somewhat flexi-ble; and the question whether or not to deal with a par-ticular treaty under the procedures laid down in theconstitution then becomes to some extent a matter ofthe political judgement of the executive, whose decisionmay afterwards be challenged in the legislature or inthe courts.8. No doubt, it remains true that in a number of casesit will be possible to say that a particular constitutionalprovision is notorious and clear and that a given treatyfalls within it. But it is equally true that in many casesneither a foreign State nor the national governmentitself can judge in advance with any certainty whether, ifcontested, a given treaty would be held under nationallaw to fall within a constitutional limitation, or whetheran international tribunal would hold the constitutionalprovision to be one that is " notorious " and " clear " forthe purposes of international law. In consequence, thecompromise solution advocated by Sir H. Lauterpachtand a number of other authorities appears only to go asmall part of the way towards removing the risks to thesecurity of treaties which arise, if constitutional limita-tions are treated as effective in international law to curtailthe authority to act for the State ostensibly possessed bycertain State agents under customary law.

9. A third group of writers 14 considers that, not only

13 United Nations Legislative Series, Laws and Practicesconcerning the. conclusion of Treaties (ST/LEG/SER. B/3).

14 E. G. Anzilotti, Cours de droit international (translationGidel) vol. 1 (1929), pp. 366-367; G. Scelle, Precis dii droit degens, vol. 2 (1934), p. 455; Sir G. Fitzmaurice, British Yearbookof International Law, vol. 15 (1934) pp. 129-137; 1. Seidl-Hohcnveldern, International and Comparative Law Quarterly,vol. 12 (1963), pp. 102-103; Blix, Treaty-Making Power (I960)chapter 24; and see UNESCO, Survey of the Ways in whichStates interpret their International Obligations, pp. 7-8.

does international law leave to each State the determina-tion of the organs and procedures by which its will toconclude treaties is formed, but it concerns itself exclu-sively with the external manifestations of this will on theinternational plane. According to this group, interna-tional law determines the procedures and conditionsunder which States express their consent to treaties onthe international plane; it regulates not only the proce-dures for expressing consent to be bound by a treatybut the conditions under which the various categories ofState agents will be recognized as competent to carry outsuch procedures on behalf of their State. This being so,if an agent, competent under international law to committhe State and apparently authorized by the governmentof the State to do so, expresses the consent of the Stateto a treaty through one of the established procedures, theState is held bound by the treaty in international law.Under this doctrine, failure to comply with constitu-tional requirements may entail the nullity of the treaty asdomestic law, and may also render the agent or the gov-ernment liable to legal proceedings under domestic law;but it does not affect the essential validity of the treatyin international law so long as the agent acted within thescope of his ostensible authority under international law.Some members of this group 15 modify the stringency ofthe rule in cases where the other State is actually awareof the failure to comply with constitutional requirementsor where the lack of constitutional authority is so mani-fest that the other State must be deemed to have beenaware of it. This compromise solution, which takes asits starting point the supremacy of the international rulesconcerning the conclusion of treaties, does not seem topresent the same logical difficulties as the compromiseput forward by the previous group. As the basic prin-ciple, according to the third group, is that a State isentitled to assume the regularity of what is done withinthe ostensible authority of an agent competent underinternational law, it is logical enough that the Stateshould not be able to do so when it knows, or must inlaw be assumed to know, that in the particular case theauthority does not exist.

10. The Commission's third Special Rapporteur, SirG. Fitzmaurice, belonged to the third group, and in histhird report on the law of treaties (A/CN.4/115) pro-posed an article (article 10) which excluded constitutionalprovisions from having any effect upon the essentialvalidity of a treaty in any circumstances. He consideredthis to be the " internationally correct " rule and the doc-trines recognizing the effectiveness of constitutional limi-tations in international law to be difficult to reconcilewith the principle of the supremacy of international overdomestic law.

11. The majority of writers adopting the constitutionalapproach to the problem appear to have arrived at theirconclusion rather upon the basis of theory than upon aclose examination of international jurisprudence andState practice. If the evidence from these sources is notentirely decisive, the weight of it seems to point to a

15 J. Basdevant, for example, while holding that States mustin general be able to rely on the ostensible authority of a Stateagent and to disregard constitutional limitations upon his autho-rity, considered that this should not be so in the case of a " vio-lation manifeste de la constitution d'un Etat "; Recueil desCours de I'Academie de droit international, 1926, vol. V, p. 581;see also the UNESCO " Survey on the Ways in which StatesInterpret their International Obligations " (P. Guggenheim), p. 8.


solution based upon the position taken by the thirdgroup. The international jurisprudence is admittedlyneither extensive nor very conclusive. The ClevelandAward 16 (1888) and the George Pinson case 17 (1928),although not involving actual decisions on the point,contain observations favouring the relevance of constitu-tional provisions to the international validity of treaties.On the other hand, the Franco-Swiss Custom case 18

(1912) and the Rio Martin case I9 (1924) contain definitedecisions by arbitrators declining to take account ofalleged breaches of constitutional limitations whenupholding the validity respectively of a protocol and anexchange of notes, while the Metzger case 20 containsan observation in the same sense. Furthermore, pro-nouncements in the Eastern Greenland 21 and FreeZones22 cases, while not directly in point, seem toindicate that the International Court will not readily gobehind the ostensible authority under international lawof a State agent — a Foreign Minister and an agentin international proceedings in the cases mentioned —to commit his State.12. As to State practice, a substantial number ofdiplomatic incidents has been closely examined in arecent work.23 These incidents certainly contain examplesof claims that treaties were invalid on constitutionalgrounds, but in none of them was that claim admittedby the other party to the dispute. Moreover, in threeinstances — the admission of Luxembourg to theLeague, the Politis incident and the membership ofArgentina — the League of Nations seems to have actedupon the principle that a consent given on the interna-tional plane by an ostensibly competent State agent isnot invalidated by the subsequent disclosure that theagent lacked constitutional authority to commit hisState. Again, depositaries of treaties, while concerningthemselves with the ostensible authority of State agentsunder international law and with the regularity of theform of full powers and instruments of ratification,acceptance, etc., have never concerned themselves withthe constitutional authority of the agent signing a treatyor depositing an instrument of ratification, accep-tance, etc. Tn one instance, the United States Govern-ment, as depositary, seems to have assumed that anostensibly regular notice of adherence to an agreementcould not be withdrawn on a plea of lack of constitu-tional authority except with the consent of the otherparties.24 Nor is it the practice of State agents, whenconcluding treaties, to cross-examine each other as to theirconstitutional authority to affix their signatures to atreaty or to deposit an instrument of ratification, accep-tance, etc. It is true that in the Eastern Greenland caseDenmark conceded the relevance in principle ofNorway's constitutional provisions in appreciating theeffect of the Ihlen declaration, while contesting theirrelevance in the particular circumstances of the case.It is also true that at the seventeenth session of theGeneral Assembly the Italian representative to the Sixth

lfi Moore, International Arbitrations, vol. 2, p. 1946.17 United Nations Reports of International Arbitral Awards,

vol. V , p . 327.18 Ibid., vol . X I , p . 4 1 1 .39 Ibid., vol . I I , p . 724.20 Foreign Relations of the United States, 1901, p . 262.21 P.C.I.J., Series A / B , No. 53, pp. 56-71 and p. 91.22 P.C.I.J., Series A / B , No. 46, p. 170.23 H. Blix, op. cit., chapter 20.21 H. Blix, op. cit., p. 267.

Committee expressed concern that certain passages inthe International Law Commission's report (A/5209)seemed to imply a view unfavourable to the relevanceof constitutional provisions in determining the questionof a State's consent in international law. But otherStates, such as Switzerland, the United States andLuxembourg, have expressed themselves very clearly inan opposite sense and the weight of State practice seemsto be the other way.

13. The present Special Rapporteur has based hisproposals upon the principle that the declaration of aState's consent to a treaty is binding upon that State,if made by an agent ostensibly possessing authorityunder international law to make the particular declara-tion on behalf of his State. In doing so, he has beenguided primarily by the indications contained in interna-tional jurisprudence and State practice and also by therules concerning the conclusion of treaties already provi-sionally adopted by the Commission in part I. Norcould he fail to take account of the fact that, in dealingwith the authority of agents to sign, ratify, etc., a treatyunder article 4 of part I and with the questions ofsignature, ratification and acceptance under articles 11,12 and 14 of that part, the Commission itself showed amarked reluctance to introduce into the provisions ofthose articles, by any form of reference, the differingconstitutional rules and practices of individual States.

14. Other more general considerations also appear tojustify the Commission's reluctance to incorporate intointernational law the constitutional provisions of indi-vidual States. International law has devised a numberof treaty-making procedures — ratification, acceptanceand approval — specifically for the purpose of enablingGovernments to reflect fully upon the treaty beforedeciding whether or not the State should become aparty to it, and also of enabling them to take accountof any domestic constitutional requirements. When atreaty has been made subject to ratification, acceptanceor approval, the negotiating States would seem to havedone all that can reasonably be demanded of them inthe way of giving effect to democratic principles oftreaty-making. It would scarcely be reasonable to expecteach Government subsequently to follow the internalhandling of the treaty by each of the other Govern-ments, while any questioning on constitutional groundsof the internal handling of the treaty by anotherGovernment would certainly be regarded as an inad-missible interference in its affairs. The same considera-tions apply in cases of accession where the Governmenthas the fullest opportunity to study the treaty and giveeffect to constitutional requirements before taking anyaction on the international plane to declare the State'saccession to the treaty. Again, in the case of a treatybinding upon signature it is the Government whichauthorizes the use of this procedure; the Governmentis aware of the object of the treaty before the negotia-tions begin and, with modern methods of communica-tion, it normally has knowledge of the exact contentsof the treaty before its representative proceeds to thea~t of signature; moreover, if necessary, its represen-tative can be instructed to sign " ad referendum'".Admittedly, in the case of treaties binding upon signa-ture, and more especially those in simplified form, theremay be a slightly greater risk of a constitutional provi-sion being overlooked; but even in these cases the

Law of Treaties 45

Government has all the necessary means of controllingthe acts of its representative and of giving effect toany constitutional requirements. In other words, in everycase any failure to comply with constitutional provi-sions in entering into a treaty will be the clear respon-sibility of the Government of the State concerned.15. The majority of the diplomatic incidents in whichStates have invoked their constitutional requirementsas a ground of invalidity have been cases in which forquite other reasons they have desired to escape fromtheir obligations under the treaty. Furthermore, in mostof these cases the other party to the dispute has contestedthe view that non-compliance with constitutional provi-sions could afterwards be made a ground for invali-dating a treaty which had been concluded by representa-tives ostensibly possessing the authority of the State toconclude it. Where a Government has genuinely founditself in constitutional difficulties after concluding atreaty and has raised the matter promptly, it appearsnormally to be able to get the constitutional obstacleremoved by internal action and to obtain any necessaryindulgence in the meanwhile from the other parties.In such cases the difficulty seems often to show itselfnot from the matter being raised in the legislative bodywhose consent was by-passed but rather in the courtswhen the validity of the treaty as internal law ischallenged on constitutional grounds.25 National courtshave sometimes appeared to assume that a treaty,constitutionally invalid as domestic law, will also beautomatically invalid on the international plane. Moreoften, however, they have either treated the interna-tional aspects of the matter as outside their provinceor have recognized that to hold the treaty constitu-tionally invalid may leave the State in default in itsinternational obligations. Confronted with a decision inthe courts impugning the constitutional validity of atreaty, a Government will normally seek to regularizeits position under the treaty by taking appropriate actionin the domestic or international sphere.16. The Special Rapporteur does not underestimatethe importance of constitutional limitations on the treaty-making power. On balance, however, he considers thatgreater importance should be attached by the Commis-sion to the need to safeguard the security of internationalagreements. The complexity of constitutional provisionsand the uncertain application even of apparently clearprovisions appear to create too substantial a risk to thesecurity of treaties, if constitutional provisions areaccepted as governing the scope of the internationalauthority of a State's agents to enter into treaties on itsbehalf. In drafting the present article, therefore, he hastaken as his starting point the principle that a State isbound by the acts of its agents done within the scopeof their ostensible authority under international law.17. Paragraph 1 defines the conditions for the aoplica-tion of the present article by setting out the kinds ofconstitutional limitation on the treaty-making powerwhich brings it into operation. As already mentionedin paragraph 1 of this Commentary, it can be contendedthat constitutional provisions which are only directedtowards the validity of treaties in internal law have nobearing on their international validity. Nevertheless

they do in practice affect the treaty-making powers ofState agents and may sometimes be invoked, even ifwrongly, as depriving State agents of constitutionalauthority to commit the State. Accordingly, it seemsdesirable to cover this kind of limitation in the article;and if " ostensible authority " is accepted as the relevantcriterion, there is no occasion for drawing a distinction,however correct juridically, between a limitation uponthe power to bind the State externally and a limitationupon the power to do so internally. If, however, theCommission were to adopt the doctrine that constitu-tional limitations are to be regarded as part of interna-tional law, it would be necessary to distinguish betweenthe two kinds of limitation.18. Paragraph 2 sets out the general rule that Statesare bound internationally by acts of their agents donewithin the scope of the authority ostensibly possessedby them under international law. Sub-paragraph (a)covers the case of treaties binding upon signature, whilesub-paragraph (b) covers that of treaties subject toratification, acceptance or approval. In both cases thecriteria for determining " ostensible authority " are therules set out in article 4 of Part I, which have alreadybeen provisionally adopted by the Commission.19. Paragraph 3 sets out the legal position whichresults from the application of the " ostensible authority "doctrine. Sub-paragraph (a) draws the logical conclusionfrom that doctrine that, if the treaty is already in forceor is brought into force by the signature or instrumentof the State in question, it may only withdraw from thetreaty with the agreement of the other parties. If theState subsequently seeks to impeach the validity of theact of its own agents, it is disturbing rights alreadyacquired by the other parties; and, having been com-mitted on the international plane by the act of its agentdone within the scope of his ostensible authority, it canonly withdraw from the treaty with the consent of theother parties.20. Logically, it would be possible to contend that asimilar rule should apply even if the treatv is not yetin force; in other words, that the unconstitutional signa-ture or instrument may even in that case be withdrawnonly with the consent of the other interested States.On the other hand, it seems reasonable that, if the treatyis not yet in force, the State should be allowed a locuspoenitentiae within which to retract the unconstitutionalact of its representative. In these cases there would beno question of the State's evading its obligations by asnecious reliance on constitutional limitations; while thedisturbance to the interests of other States would beminimal. Accordingly, sub-paragraph (b) proposes delege jerenda that there should be a unilateral right ofwithdrawal at any time up to the entry into force of thetreaty.21. Paragraph 4, sub-paragraph (a), qualifies the" ostensible authority " doctrine to the extent of recog-nizing that actual knowledge of a representative's lackof constitutional authority negatives the right to regardhim as ostensiblv possessing authority to bind his State.Good faith precludes another State from claiming tohave relied upon an authority which it knew was notin fact possessed by the representative who purportedto commit his State. A number of authorities 2 3 also

23 E.g. Prosecution for Misdemeanours (Germany) case,(International Law Reports, 1955, pp. 560-1); Belgian Statev. Leroy (ibid., pp. 614-6).

26 E.g. J. Basdevant, Recueil des Coins, 1926, Vol. V,p. 581; P. De Visscher, op. cit., pp. 272-3.


admit as an exception to the " ostensible authority "doctrine cases where the lack of the agent's authority is" manifest ". It is certainly possible to imagine caseswhere the very question of constitutional authority hasbeen ventilated in Parliament or the Press and the lackof authority can be said to be " manifest "; or wherethe treaty is of such a kind as to render the need forspecial constitutional authority self-evident. In thesecases again, it can be said, it would be inconsistent withgood faith to claim to have relied on the existence ofan authority which any reasonable person would haveknown did not exist. On the other hand, the chief meritof the " ostensible authority " doctrine is to exclude theneed for negotiating States to investigate each other'sinternal constitutional situation, and it is essential toavoid any qualification of the doctrine that wouldreintroduce the need for such investigations. From thispoint of view there may be a little hesitation in admittingthe exception of " manifest " lack of constitutionalauthority; but the Special Rapporteur has included it inparagraph 4 for the Commission's consideration.

22. Paragraph 4, sub-paragraph (b) provides thatwhere the lack of constitutional authority was knownby or manifest to other States at the time, it can beinvoked to annul the unauthorized act of the agent,unless the State has claimed benefits or asserted obliga-tions arising under the treaty or has otherwise precludeditself by its conduct from denying its consent to bebound by the treaty. These provisos are important, sincethe danger is that a State may refrain from raising theconstitutional objection to its participation in the treatyuntil the day comes when, having long acted as if thetreaty was valid, it suddenly finds that it is inconvenientto carry out its obligations. The article 4 referred to insub-paragraph (b) (ii) is the general article recognizingthe relevance of the principle of preclusion (estoppel)in cases where a State claims to annul or denounce atreaty for lack of essential validity.

Article 6 — Particular restrictions upon the authorityof representatives

1. If a representative, who neither possesses ostensibleauthority under article 4 of part I to bind the State norspecific authority to do so with regard to the particulartreaty, purports to bind the State by an unauthorizedsignature or by an unauthorized exchange or depositof an instrument, the State concerned may repudiatethe act of its representative, provided that it has not —

(a) subsequently ratified the unauthorized act of itsrepresentative;

(b) so conducted itself as to bring the case within theprovisions of article 4 of this part.

2. (a) When a representative, possessing ostensibleauthority under article 4 of part I to bind his State, isgiven instructions by his State which restrict thatauthority in particular respects, the instructions shallonly be effective to limit his authority if they are madeknown to the other interested States before the Statein question enters into the treaty.

(b) In such a case, if the representative disregards therestrictions imposed upon him by his instructions, theState may repudiate his unauthorized act, subject to thesame provisos as those set out in paragraph 1 of thisarticle.

Commentary1. Article 6 seeks to cover cases where a representativemay purport by his act to bind the State but in factlacks authority to do so. This may happen because,not possessing ostensible authority under internationallaw to bind the State in accordance with the provisionsof article 4 of part I, he also lacks any specific authorityfrom his Government to enter into the treaty on itsbehalf; or it may happen because, while possessingostensible authority under international law, he is subjectto express instructions from his Government whichlimit his authority in the particular instance. Neithertype of case is common but both types have occasionallyoccurred in practice.27

2. Where a treaty is not to become binding withoutsubsequent ratification, acceptance or approval, anyexcess of authority committed by a representative inestablishing the text of the treaty will automatically beironed out at the subsequent stage of ratification, accep-tance or approval. The State in question will then havethe clear choice either of repudiating the text establishedby its representative or of ratifying, accepting orapproving the treaty; and if it does the latter, it willnecessarily be held to have endorsed the unauthorizedact of its representative and, by doing so, to have curedthe original defect of authority. Accordingly, the presentarticle is confined to cases in which the defect ofauthority relates to the execution of an act by which arepresentative purports finally to establish his State'sconsent to be bound. These cases may arise either uponthe unauthorized signing of a treaty, which is to becomebinding upon signature, or when a representative,authorized to exchange or deposit a binding instrumentunder certain conditions or subject to certain reserva-tions, exceeds his authority by failing to comply withthe conditions, or to specify the reservations, whenexchanging or depositing the instrument.

3. Paragraph 1 of the article deals with cases wherethe representative lacks any authority to enter into thetreaty. In 1908, for example, the United States Ministerto Romania signed two conventions without having anyauthority to do so.28 With regard to one of these conven-tions his Government had given him no authority atall, while he had obtained full powers for the other byleading his Government to understand that he was tosign a quite different treaty. More recently — in 1951— a convention concerning the naming of cheesesconcluded at Stresa was signed by a delegate on behalfboth of Norway and Sweden, whereas it appears that hehad authority to do so only from the former country.In both these instances the treaty was, in fact, subjectto ratification but they serve to illustrate the kind ofcases that may arise.29 Another case, in which the samesituation may arise, and one more likely to occur inpractice, is that where an agent has authority to enterinto a particular treaty, but goes beyond his full powersby accepting unauthorized extensions or modificationsof it. An instance of such a case was Persia's attempt,

27 See generally H . Blix, op. cit., pp . 5-12 and 76-82.28 Hackv/orth, Digest of International Law, Vol . IV, p . 467.29 Cf. also the well-known historical incident of the

British Government ' s disavowal of an agreement between aBritish Political Agent in the Pers ian Gulf and a PersianMinister which the British Governmen t afterwards said hadbeen concluded without any authori ty whatever ; Adamyia t ,Bahrein Islands, p . 106.

Law of Treaties 47

in discussions in the Council of the League, to disavowthe Treaty of Erzerum of 1847 on the ground that thePersian representative had gone beyond his authorityin accepting a certain explanatory note when exchangingratifications.3'4. Where there is no ostensible or express authorityto enter into a treaty, it seems clear, on principle, thatthe State must be entitled to repudiate the act of itsrepresentative and paragraph 1 so provides. On theother hand, it seems equally clear that, notwithstandingthe representative's original lack of authority, the Statemay afterwards endorse and validate his act, and willbe held to have done so by implication if it invokesthe provisions of the treaty or otherwise acts in such away as to lead the other parties to assume that it regardsitself as bound by the act of its representative. In otherwords, it will not be entitled to invoke its representa-tive's lack of authority in cases where it has disableditself from doing so under the principle of preclusion(estoppel) set out in article 4.5. Paragraph 2 of the article deals with the othertype of case where ostensible authority exists but hasbeen curtailed by specific instructions. In principle, andin order to safeguard the security of international tran-sactions, the rule, it is suggested, must be that specificinstructions given by a State to its representative areonly effective to limit his authority vis-a-vis other States,if they are made known to the other States in someappropriate manner before the State in question entersinto the treaty. That this is the rule acted on by Statesis perhaps suggested by the rarity of cases in which aState has sought to disavow the act of its representativeby reference to secret limitations upon his authority.In the incident in 1923 of the Hungarian representative'ssignature of a resolution of the Council of the League,the Hungarian Government sought to disavow his actby interpreting the scope of his full powers, ratherthan by contending that he had specific instructionslimiting their exercise. The Council of the League seemsclearly to have held the view that a State may notdisavow the act of an agent done within the scope ofthe apparent authority conferred upon him by his fullpowers.6. Paragraph 2 of the article therefore provides thatspecific instructions are only to be taken into accountif disclosed to the other parties before the State in ques-tion enters into the treaty.

Article 7 — Fraud inducing consent to a treaty

1. Where one party to a treaty has been induced toenter into it by the fraud of another, the former shallbe entitled after discovering the fraud —

(a) to declare that the fraud nullifies its consent tobe bound by the treaty ab initio; or

(b) to denounce the treaty, subject to the reservationof its rights with respect to any loss or damage resultingfrom the fraud; or

(c) to affirm the treaty, subject to the same reserva-tion.

2. Fraud inducing entry into a treaty comprises —(a) the making of false statements or representations

of fact either in the knowledge that they are false orwithout regard to whether they are true or false, for the

30 For further cases, see H. Blix, op. cit., pp. 77-81.

purpose of procuring the consent of a State to be boundby the terms of a treaty; or

(b) the concealment or non-disclosure of a materialfact for such a purpose where the information relatingto the fact in question is in the exclusive possession orcontrol of one party only and the circumstances of thetreaty are such that good faith requires the disclosureof all material facts.3. Paragraph 1 of this article shall not, however, applywhere —

(a) the adoption of the text of a treaty, which issubject to ratification, acceptance or approval, has beenprocured by fraud but, after discovering the fraud, theState nevertheless proceeds to ratify, accept or approvethe treaty; or

(b) the defrauded State has so conducted itself as tobring the case within the provisions of article 4 of thispart.

Commentary1. There does not appear to be any recorded instanceof a State claiming to annul or denounce a treaty on theground that it had been induced to enter into the treatyby the fraud of the other party. The only instance men-tioned in the books as one where the matter wasdiscussed at all is the Webster-Ashburton Treaty of1842 relating to the North-Eastern boundary betweenthe United States and Canada.31 That, however, was acase of non-disclosure of a material map by the UnitedStates in circumstances in which it was difficult to saythat there was any legal duty to disclose it, and GreatBritain did not assert that the non-disclosure amountedto fraud.2. Clearly, cases in which Governments resort to deli-berate fraud in order to obtain the conclusion of a treatyare not very likely to occur, while cases of fraudulentmisrepresentation of material facts would in any eventbe largely covered by the provisions of the next articleconcerning the effects of error. The question may there-fore be asked whether there is any need to include anarticle dealing specifically with fraud. The drafts ofSir H. Lauterpacht and Sir G. Fitzmaurice contain suchan article, as did also the Harvard Research Draft; and,on balance, the present Special Rapporteur feels that thedraft articles should include provisions concerning fraud,even although their application may be rare. Fraud,when it does occur, strikes at the root of a treaty, asof a contract, in a rather different way from innocentmisrepresentation and error; it destroys the basis ofmutual confidence between the parties as well asnullifying the consent of the defrauded party.3. Sir H. Lauterpacht's draft was somewhat laconic,speaking simply of " a treaty procured by fraud "; thatof Sir G. Fitzmaurice was a good deal more elaborate,reproducing in some detail provisions of municipal lawconcerning fraud. While not disputing the relevanceof municipal law concepts in appreciating the implica-tions of fraud in the law of treaties, the present SpecialRapporteur does not consider that all the points madeby Sir G. Fitzmaurice need be expressed in the presentarticle.4. Paragraph 1 sets out suggested rules for determiningthe effects of fraud on the validity of treaties. Fraud,it is commonly said, undermines the reality of the consent

31 See Moore, Digest of International Law, vol. 5, p. 719.


and, as in the case of a contract, renders the treatyvoidable. Treaties are employed for very diverse legalpurposes — legislative, dispositive, contractual, etc., —and a State induced to enter into a treaty by fraudshould, it is thought, have the option of avoiding thetreaty ab initio, avoiding it as from the date of thediscovery of the fraud, or affirming it, according as itsinterests and the circumstances of the case require.5. Paragraph 2 defines fraud as comprising wilful orreckless mis-statements or misrepresentations of fact and,in addition, non-disclosure, where good faith requiresfull disclosure of material facts. Just as municipal lawknows of classes of contract — e.g., insurance contracts— which are regarded as " uberrimae fidei " so theremay, it is thought, be treaties where good faith requiresthe mutual disclosure of material facts. The Webster-Ashburton Treaty of 1842 was a boundary treaty andin such a case it may be there was no legal obligationto disclose the existence of a map, when access to themap could have been obtained by the other party. Butit is easy to imagine treaties of mutual co-operation,e.g., treaties for the mutual exploitation and use ofwater resources, where non-disclosure of a material fact,e.g., the existence of an underground stream, would notbe consistent with good faith. Accordingly, withoutattempting to give detailed classifications of such cases,it seemed desirable to provide for their possible occur-rence. This seems also to have been the view of theprevious Special Rapporteur.

6. Paragraph 3 excepts from the rule in paragraph 1cases where a treaty is subject to ratification, acceptanceor approval and fraud used to procure its adoption hasbeen discovered before the act of ratification, accep-tance or approval takes place. In such a case, the Stateis completely free to refuse to enter into the treaty. Butif, knowing of the fraud used in the drawing up ofthe treaty, it nevertheless elects to enter into thetreaty, with or without reservations, it clearly cannotafterwards invoke the fraud to disavow its act ofratification, acceptance or approval. Paragraph 3 alsoexcepts from paragraph 1 cases where the State hasdisabled itself from invoking the fraud under the prin-ciple of preclusion (estoppel) set out in article 4.

Article 8 — Mutual error respecting the substanceof a treaty

1. Where a treaty has been entered into by the partiesunder a mutual error respecting the substance of thetreaty, any party shall be entitled to invoke the erroras invalidating its consent to be bound by the treaty,provided that:

(a) the error was one of fact and not of law;{b) the error related to a fact or state of facts assumed

by the parties to exist at the time that the treaty wasentered into;

(c) the assumed existence of such fact or state offacts was material in inducing the consent of the Statesconcerned to be bound by the terms of the treaty.2. In any such case the party in question may —

(a) regard the error as nullifying ab initio its consentto be bound by the treaty; or

(b) by mutual agreement with the other party orparties concerned, either (i) denounce the treaty asfrom such date as may be decided, or

(ii) affirm the treaty subject to any modifications thatmay be decided upon in order to take account of theerror.3. However, a party shall not be entitled to invoke anerror as invalidating its consent to be bound where —

(a) the party in question contributed by its ownconduct to the error, or could by the exercise of duediligence have avoided it, or if the circumstances weresuch as to put that party on notice of the possibility ofthe error; or

(b) the party in question has so conducted itselfas to bring the case within the provisions of article 4of this part.

Article 9 — Error by one party only respecting thesubstance of a treaty

1. Where only one or some of the parties to a treatyhas or have entered into it under an error answering tothe conditions set out in article 8, paragraph 1, suchparty or parties shall only be entitled to invoke the erroras invalidating its or their consent to be bound by thetreaty, if the error was induced by the innocent mis-representation, negligence or fraud of the other party orparties.2. In any such case the party or parties in questionshall be entitled after discovering the error:

(a) to declare that the error nullifies its consent to bebound by the treaty ab initio; or

(b) to denounce the treaty, subject to the reservationof its rights with respect to any loss or damage resultingfrom the error; or

(c) to affirm the treaty, subject to the same reserva-tion.3. However, in the case of a State acceding to a treatyin the conclusion of which it did not take part, it mayinvoke an error as invalidating its consent to be boundby the treaty under the same conditions as those laiddown for mutual error in article 8.

Commentary (articles 8 and 9)1. These articles cover error in the formation ofconsent to a treaty, while the next article deals witherror in the expression of a consent which was itselfarrived at without any error. In municipal law erroroccupies a comparatively large place as a factor whichmay nullify the reality of consent to a contract. Sometypes of error found in municipal law, however, canhardly be imagined as operating in the field of treaties,e.g., error in persona. Similarly, some types of treaty,more especially law-making treaties, appear to affordlittle scope for error in substantia to affect the formationof consent, even if that may not be impossible. More-over, treaty-making processes are such as to reduce toa minimum the risk of errors on material points ofsubstance. In consequence, the instances in which errorsof substance have been invoked as affecting the essentialvalidity of a treaty have not been frequent.2. Almost all the recorded instances concern geogra-phical errors,32 and most of them concern errors in

32 See Harvard Law School: Research in InternationalLaw, III, Law of Treaties, pp. 1127-8; Hyde, A.J.I.L. 1933,p. 311; and Repertoire frangais de droit international public,Vol. I, pp. 55-6.

Law of Treaties 49

maps. In some instances, the difficulty was disposedof by a further treaty; in others the error was treatedmore as affecting the application of the treaty than itsvalidity and the point was settled by arbitration. Theseinstances confirm the possible relevance of errors inregard either to the validity of treaties or to theirapplication, but they do not provide clear guidance asto the principles governing the effect of error on theessential validity of treaties.3. The effect of error on treaties was, however, dis-cussed in the Eastern Greenland case 33 before the Per-manent Court of International Justice, and again in theTemple case 34 before the present Court. In the formercase Norway contended that, when asked by the DanishAmbassador to say that Norway would not object tothe Danish Government's extending its political andeconomic interests over the whole of Greenland, herForeign Minister had not realized that this covered theextension of the Danish monopoly regime to the wholeof Greenland; and that accordingly his acquiescence inthe Danish request had been vitiated by error. The Courtcontented itself with saying that the Foreign Minister'sreply had been definitive and unconditional and appearsnot to have considered that there was any relevant errorin the case. Judge Anzilotti, while also considering thatthere was no error, went on to say: " But even accepting,for a moment, the supposition that M. Ihlen wasmistaken as to the results which might ensue from anextension of Danish sovereignty, it must be admittedthat this mistake was not such as to entail the nullityof the agreement. If a mistake is pleaded it must beof an excusable character; and one can scarcely believethat a Government could be ignorant of the legitimateconsequences following upon an extension of sove-reignty . . . " 3 5 In other words, he seems to haveregarded the error as essentially one of law and not,therefore, " excusable ". In the recent Temple case theerror, which was geographical, arose in somewhat specialcircumstances. There was no error in the conclusion ofthe original treaty, in which the parties were agreed thatthe boundary in a particular area should be the lineof a certain watershed; the error concerned what theCourt held to be a subsequent, implied, agreement to

vary the terms of the treaty. Siam had accepted a mapprepared bona fide for the purpose of delimiting theboundary in the area in question, but showing a linewhich did not follow the watershed. Rejecting Siam'splea that her acceptance of the map was vitiated byerror, the Court said: " It is an established rule of lawthat the plea of error cannot be allowed as an elementvitiating consent, if the party advancing it contributedby its own conduct to the error, or could have avoidedit, or if the circumstances were such as to put that partyon notice of a possible error." 38

4. The Eastern Greeland and Temple cases throw lighton the conditions under which error will not nullify thereality of the consent rather than on those under whichit will do so. The only further guidance which canperhaps be obtained from the Court's decisions is in theMavrommatis Concessions case 3 : which, however, con-

33 P.C.I.J., Series A / B , N o . 53 , pp . 71 and 9 1 .34 I.C.J. Reports, 1962, p . 26; see also the individual opi-

nion of Judge Fi tzmaurice , p . 57.35 P.C.I.J., Series A / B , N o . 53 , p . 92.36 I.CJ. Reports, 1962, p. 26.37 P.C.I.J., Series A, No. 11.

cerned a concession, not a treaty. There the Courtheld that an error in regard to a matter not constitutinga condition of the agreement would not suffice to inva-lidate the consent; and it seems to be generally agreedthat, to negative consent to a treaty, an error mustrelate to a matter considered by the parties to form anessential basis of their consent to the treaty.

Commentary to article 85. This article deals with cases where both or all theparties are in error as to the substance of the treaty.Paragraph 1 states the conditions under which such anerror may be invoked as invalidating consent. Sub-para-graphs (a), (b) and (c) reproduce the classical require-ments for establishing error in the law of contract, whichare also applicable in the law of treaties. These require-ments were elaborated somewhat in Sir G. Fitzmaurice'sdraft in his third report (A/CN.4/115) so as to distin-guish further between errors of fact and errors ofjudgement or of motive, and to emphasize the distinctionbetween errors of fact and errors of expectation.However, these distinctions appear to be implied in therequirements set out in sub-paragraphs (a), (b) and (c);while the distinction between an error of fact and ofopinion may sometimes call for nice judgement in thelight of the particular circumstances of the case.Accordingly, it seems preferable to state the require-ments in simple form, leaving their application to anygiven case to be appreciated in the light of its circum-stances.6. Paragraph 2 sets out the position of the parties incases of mutual error. Clearly, where the error relatesto an essential point of substance, any one of the partiesis entitled to regard it as nullifying ab initio its consentto be bound by the treaty. This is a decision which eachparty has the right to take unilaterally, and sub-para-graph (a) so provides. On the other hand, treaties areof very different kinds, fulfilling very varied functions;and it may be that in some cases it may not be desirableor even practicable for the parties, on discovering theerror, to regard the treaty as void ab initio. Accordingly,sub-paragraph (b) provides for the possibility that theparties may prefer to avoid the treaty as from a givendate or to affirm it with modifications. These courses, itseems evident, could only be adopted by agreementbetween the interested States.

7. Paragraph 3 (a) lays down, as an exception to therule contained in paragraph 1, that a party may notinvoke an error as invalidating its consent to be boundwhere the error is not w excusable ". The formulation ofthe exception is in substantially the same terms as thoseused by the Court in the Temple case (see paragraph 3above).8. Paragraph 3 (b) also reserves from the rule in para-graph 1 cases where a party has precluded (estopped)itself from relying on a plea of error under the principlesset out in article 4.

Commentary to article 9

9. Article 9 deals with cases of unilateral error, andthe general view seems to be that unilateral error cannotbe invoked to invalidate a treaty unless it was inducedby the innocent misrepresentation, negligence or fraudof the other party, and paragraph 1 so provides.10. The position of a party which has been led intoerror by the fault of the other party would seem to be


similar to that of a party induced to enter into a treatyby fraud. The party concerned should have the righteither to avoid the treaty ab initio, to denounce it or toaffirm it while reserving its rights with respect to anyresulting loss. The position is so stated in paragraph 2.11. Paragraph 3 deals with the special case of a Stateled to accede to a treaty through error. Although theerror may be of a unilateral character, the position ofan acceding State is rather different from that of anoriginal party led to enter into the treaty through error.The draft follows that of the previous Rapporteur inassimilating the case of error on the part of an accedingState to one of mutual error.

Article 10 — Errors in expression of the agreement

1. Where a treaty has been entered into with respectto whose substance the parties were mutually agreed,but the text of which contains an error in the expressionof their agreement, the error may not be invoked byany party as invalidating its consent to be bound by thetreaty.2. In any such case articles 26 and 27 of part I shallapply.

Commentary1. An error, which does not relate to the substance ofwhat was agreed but merely to the expression of it inthe text of the treaty, clearly does not detract from theessential validity of the treaty; and paragraph 1 of thisarticle so provides.2. Errors of expression, on the other hand, may leadto difficulties and divergent interpretations, and it isdesirable that they should, if possible, he corrected.Paragraph 2 therefore draws attention to articles 26and 27 of part I, which deal with the procedures forcorrecting errors.3. As pointed out in the Commentary to article 26 ofpart I, the correction of errors by these procedures isonly possible where the parties are agreed as to theexistence of the error in the expression of their agree-ment. Where the error is not agreed, the problem isone of " mistake ", which falls under articles 8 and 9of the present part. In cases where there is no agreementas to an alleged error in expression and the allegederror does not affect the essential validity of the treatyunder articles 8 and 9, the question becomes one ofinterpretation. The treaty stands and the difficulty as toits content has to be resolved by the application of thenormal rules for the interpretation of treaties.

Article 11—Personal coercion of representativesof States or of members of State organs

1. If coercion, actual or threatened, physical or mental,with respect to their persons or to matters of personalconcern, has been employed against individual represen-tatives of a State or against members of an organ ofthe State in order to induce such representative or organto sign, ratify, accept, approve or accede to a treaty,the State in question shall be entitled after discoveringthe fact —

(a) to declare that the coercion nullifies the act of itsrepresentative ab initio; or

(b) to denounce the treaty, subject to the reservationof its rights with respect to any loss or damage resultingfrom the coercion; or

(c) to approve the treaty, subject to the same reserva-tion.2. Paragraph 1 does not apply, however, where —

(a) a treaty, which is subject to ratification, accep-tance or approval, has been signed by a representativeunder coercion but, after discovering the coercion, theState proceeds to ratify, accept or approve the treaty; or

(b) the State has so conducted itself as to bring thecase within the provisions of article 4 of this part.

CommentaryThere appears to be general agreement that acts of

coercion or threats applied to individuals with respectto their own persons or personal affairs in order toprocure the signature, ratification, acceptance orapproval of a treaty will necessarily justify the State inrepudiating the treaty.38 History provides a number ofalleged instances of the employment of coercion againstnot only negotiators but members of legislatures in orderto procure the signature or ratification of a treaty.Amongst these instances the Harvard Research Draftlists: 39 the surrounding of the Diet of Poland in 1773to coerce its members into accepting the treaty of parti-tion; the coercion of the Emperor of Korea and hisministers in 1905 to obtain their acceptance of a treatyof protection; the surrounding of the national assemblyof Haiti by United States forces in 1915 to coerce itsmembers into ratifying a convention. Another instancefrom more recent history was the third-degree methodsemployed in 1939 by the Hitler regime to obtain thesignatures of the President and Foreign Minister ofCzechoslovakia to a treaty creating a German protec-torate over Bohemia and Moravia, althoug in thatinstance the coercion was a mixture of personal pressureon the individuals and threats against their people.40

2. The question how far coercion of the State itself,whether by acts or threats, may afford a ground forrepudiating a treaty is more controversial. Moreover,although it may not always be possible to distinguishcompletely between pressure upon the State and per-sonal pressure upon individual ministers or represen-tatives of the State, the two kinds of coercion areessentially different. The Special Rapporteur has accord-ingly dealt with them in separate articles, and the effectupon the validity of a treaty of its having been procuredby the coercion of the State itself is considered in thenext article.3. Paragraph 1, therefore, refers to coercion of indi-vidual representatives of the State or members of Stateorgans " with respect to their persons or to matters ofpersonal concern ". This phrase is intended to confinethe coercion covered by this article to coercion of theindividual as distinct from the State, and yet to be broadenough to include such forms of coercion of the indi-vidual as threats directed against his family or depen-dents. The explicit reference to " physical or mental "coercion is also designed to underline that coercion isnot confined to acts or threats of physical force.4. The position of a State confronted by the fact thatcoercion was used against its representatives or membersof its administration to obtain the conclusion of a treaty

38 McNai r , op. cit., pp . 207-209.39 Pages 1155-9.40 See Repertoire frangais de droit international public,

vol. 1, pp. 52-54.

Law of Treaties 51

would seem to be similar to that of one confrontedwith a case of fraud. The provisions of paragraph 1 ofthis article therefore conform closely to those of para-graph 1 of article 7.

5. In the same way, the provisions of paragraph 2of this article correspond to those of paragraph 3 ofarticle 7, since on these points also the position seemsto be the same in cases of coercion as in fraud.

Article 12 — Consent to a treaty procured by the illegaluse or threat of force

1. If a State is coerced into entering into a treatythrough an act of force, or threat of force, employedagainst it in violation of the principles of the Charter ofthe United Nations, the State in question shall beentitled —

(a) to declare that the coercion nullifies its consent tobe bound by the treaty ab initio; or

(b) to denounce the treaty, subject to the reservationof its rights with respect to any loss or damage resultingto it from having been coerced into the treaty; or

(c) to affirm the treaty, subject to the same reserva-tion, provided always that no such affirmation shall beconsidered binding unless made after the coercion hasceased.2. Paragraph 1 does not apply, however, where afterthe coercion has ceased the State has so conducted itselfas to bring the case within the provisions of article 4 ofthis part.

Commentary

1. The traditional doctrine prior to the Covenant ofthe League was that the validity of a treaty was notaffected by the fact that it had been brought about by thethreat or use of force. However, this doctrine was simplya reflection of the general attitude of international lawduring that era towards the legality of the use of armedforce for the settlement of international disputes; andwith the Covenant and the General Treaty for theRenunciation of War, 1927 (Pact of Paris) there began todevelop a strong body of opinion which advocatedthat the validity of such treaties ought no longer to beadmitted. The declaration of the criminality of aggressivewar in the Nuremberg and Tokyo Charters, the clear-cut prohibition of the threat or use of force in Article 2,paragraph 4, of the Charter of the United Nations andthe practice of the United Nations itself has reinforcedand crystallized this opinion. If the use or threat ofarmed force in pursuit of national policies is now incertain circumstances to be considered criminal underinternational law, it is natural to question the possibilityof regarding treaties procured by or resulting fromsuch criminal acts as valid treaties binding upon thevictims of the aggression.

2. Sir H. Lauterpacht, in his first report (A/CN.4/63,ad article 12), submitted a strongly reasoned argumentto the Commission urging it to hold that a change hascome about in international law on this point. In doingso, he said, the Commission would be " codifying notdeveloping, the law of nations in one of its most essen-tial aspects ". He conceded that to allow States too easilyto denounce treaties by making unilateral assertions ofcoercion might open the door to the evasion of treaties;but he proposed to meet the difficulty by providing that

a treaty was only to be invalid on the ground of coercion,if so declared by the International Court of Justice.3. Sir G. Fitzmaurice, on the other hand, while recog-nizing the strength of present-day opinion on thepoint, considered that the practical difficulties in theway of admitting coercion of the State as a ground forthe invalidity of a treaty are too great. These difficultieshe summarized as follows:

" The case must evidently be confined to the useor threat of physical force, since there are all toonumerous ways in which a State might allege that ithad been induced to enter into a treaty by pressure ofsome kind (for example, economic). On this latterbasis a dangerously wide door to the invalidation oftreaties, and hence a threat to the stability of thetreaty-making process, would be opened. If, however,the case is confined (as it obviously must be) to theuse or threat of physical force, what follows? Eitherthe demand for the treaty in question is acceded to,or it is not. If it is not, then cadit quaestio. If, percontra, it is, then the same compulsion or threat thatprocured the conclusion of the treaty will ensure itsexecution; and by the time, if ever, that circum-stances permit of its repudiation, it will have beencarried out, and many steps taken under it will beirreversible, or reversible, if at all, only by further actsof violence. It is this type of consideration, and notindifference to the moral aspects of the question,which has led almost every authority thus far to takethe view that it is not practicable to postulate theinvalidity of this type of treaty, and that if peace is apermanent consideration, it must follow logically thatpeace may, in certain circumstances, have to takeprecedence for the time being over abstract justice."(A/CN.4/115, para. 62).

These objections led him to the conclusion that thesubject is only part of the wider problem of what exactly,in the light of modern conditions and juristic ideas,should be the consequences of the illegitimate use orthreat of force; and that it is both inappropriate andundesirable to attempt to deal with the treaty aspect ofthe problem in isolation.4. The practical difficulties which led the previousSpecial Rapporteur to omit forcible coercion of theState itself from his draft articles on the essential validityof treaties are, of course, those which are generallyrecognized to constitute an obstacle to the effectivenessof the principle of the non-recognition of situationsbrought about by illegal uses of force. Important thoughit may be to recognize the existence of these difficulties,they do not appear to be of such a kind as to call for theomission from the present articles of any mention of aprinciple which derives from the most fundamental pro-visions of the Charter and the general relevance of whichto the validity of treaties cannot today be regarded asopen to question. The facts, that sometimes it may not bepossible to restore a treaty situation as it was before anaggression took place, and that sometimes the i'apse oftime may ultimately render an illegal treaty situationpermanent, do not seem sufficient arguments for notproclaiming the invalidity in law of a treaty broughtabout by an illegal use or threat of force and the legalright of the coerced State to set it aside. Even if a Stateshould initially be successful in achieving its objects byan aggressive use of force, it cannot be assumed that the


right to set aside a treaty resulting from aggression willnever prove to be relevant in the subsequent evolutionof world politics; the very existence of the United Nationsgives a certain guarantee that that right may provemeaningful, if subsequent events should furnish anopportunity for its legitimate exercise. In the same way,the existence of the United Nations also providesmachinery through which the international communitycan have a voice in the way in which the right is exer-cised, so as to minimize the risks to international peacementioned by Sir G. Fitzmaurice.

5. Nor is it thought that to allow coercion of the Stateas a ground for contesting the validity of a treaty wouldinvolve any undue risks to the general security of inter-national treaties, unless " coercion " is extended to coverother acts than the use or threat of force. Such risk asthere may be does not seem to be materially greater inthe case of " coercion " than in the case of some othergrounds of invalidity, such as fraud and error. Therisk lies in unilateral and mala fide assertions of " coer-cion " as a mere pretext for denouncing a treaty that isnow thought to be disadvantageous. But if invalidity oftreaties on the ground of coercion is confined to treatiesprocured by the use or threat of force, the possibilities ofa plausible abuse of this ground of invalidity do notappear to be any more substantial than in cases of fraudor error or than in cases of termination of treaties on theground of an alleged breach of the treaty or of a funda-mental change in the circumstances (rebus sic stantibus).6. On the other hand, if " coercion " were to be re-garded as extending to other forms of pressure upon aState, to political or economic pressure, the door tothe evasion of treaty obligations might be opened verywide; for these forms of " coercion " are much lesscapable of definition and much more liable to subjectiveappreciations. Moreover, the operation of political andeconomic pressures is part of the normal working of therelations between States, and international law does notyet seem to contain the criteria necessary for formulatingdistinctions between the legitimate and illegitimate usesof such forms of pressure as a means of securing consentto treaties. Accordingly, while accepting the view thatsome forms of " unequal " treaty brought about bycoercion of the State must be regarded as lacking essen-tial validity, the Special Rapporteur feels that it wouldbe unsafe in the present state of international law toextend the notion of " coercion " beyond the illegal useor threat of force.7. It is, indeed, important to stress that only treatiesresulting from an illegal use or threat of force arelacking in essential validity; for otherwise the securityof armistice agreements and peace settlements, whetherlegitimate or illegitimate, would be endangered and thedifficulty of terminating hostilities increased. Clearly,there is all the difference in the world between coercionused by an aggressor to consolidate the fruits of hisaggression in a treaty and coercion used to impose apeace settlement upon an aggressor. As one writer haspointed out,41 the validity of the peace settlements of theFirst World War was never questioned in the numerouscases in which they came under discussion before thePermanent Court or in the innumerable proceedingsarising out of them before arbitral tribunals. Again,

while the treaty of 1939 between Nazi Germany andCzechoslovakia is generally regarded as invalid by rea-son of the coercion both of the delegates and theState,42 the validity of the Italian Peace Treaty, a treatycertainly not negotiated but imposed, has not beenregarded as open to challenge.43

Article 13 — Treaties void for illegality

1. A treaty is contrary to international law and voidif its object or its execution involves the infringement ofa general rule or principle of international law having thecharacter of jus cogens.2. In particular, a treaty is contrary to internationallaw and void if its object or execution involves —

(a) the use or threat of force in contravention of theprinciples of the Charter of the United Nations;

(b) any act or omission characterized by interna-tional law as an international crime; or

(c) any act or omission in the suppression or pun-ishment of which every State is required by internationallaw to co-operate.3. If a provision, the object or execution of whichinfringes a general rule or principle of international lawhaving the character of jus cogens, is not essentiallyconnected with the principal objects of the treaty and isclearly severable from the remainder of the treaty, onlythat provision shall be void.4. The provisions of this article do not apply, however,to a general multilateral treaty which abrogates ormodifies a rule having the character of jus cogens.

Commentary1. The question how far international law recognizesthe existence within its legal order of rules having thecharacter of jus cogens is controversial. Some writers,considering that the operation even of the most generalrules of international law still falls short of being univer-sal, deny that any rule can properly be regarded as ajus cogens, from which individual States are not com-petent to derogate by treaties between themselves.44

Imperfect though the international legal order may be,the view that in the last analysis there is no internationalpublic order — no rule from which States cannot attheir own free will contract out — has become increas-ingly difficult to sustain. The law of the Charter concern-ing the use of force and the development — howevertentative — of international criminal law presupposesthe existence of an international public order contain-ing rules having the character of jus cogens. TheCommisssion will therefore, it is believed, be fully justi-fied in taking the position in the present articles thatthere are certain rules and principles from which Statescannot derogate by merely bilateral or regional treatyarrangements.45

2. The formulation of the rule, however, is not freefrom difficulty, since there is not as yet any generallyaccepted criterion by which to identify a general rule ofinternational law as having the character of jus cogens.

41 McNai r , op. cit., p . 209.

42 Ratz-Lienert and Klein v. Nederlands Beheers-Instituut(International Law Reports, 1957, p . 536).

43 Cf. Re Rizzo and Others (International Law Reports,1952, p . 478).

44 See for example G. Schwarzenberger , International Law(3rd edition), vol. I, pp . 426-427.

45 See McNai r , op. cit., pp . 213-4.

Law of Treaties 53

Moreover, it is undeniable that the majority of thegeneral rules of international law do not have that char-acter and that States may contract out of them by treaty.Sir H. Lauterpacht, althought emphasizing that Statesare largely free to modify by treaty the application ofcustomary law as between themselves, proposed asomewhat broad criterion. A treaty would be void underhis draft if its performance involved an act " illegalunder international law " (A/CN.4/63, article 15),Unless the concept of what is " illegal under interna-tional law " is narrowed by reference to the concept ofjus cogens, it may be too wide. The general law ofdiplomatic immunities makes it illegal to do certain actswith regard to diplomats; but this does not precludeindividual States from agreeing between themselves tocurtail the immunities of their own diplomats. Thephrase " illegal under international law " would alsoseem open to the interpretation that any treaty infringingthe prior rights of another State is ipso facto void. Thisdoes, indeed, appear to have been the view of SirH. Lauterpacht; but the evidence hardly seems to bearit out, especially in regard to treaties which conflict withthe rights of other States under prior treaties.

3. Sir G. Fitzmaurice, on the other hand, expressed therule in terms limiting the cases of illegality to infringe-ments of rules of the nature of jus cogens. The presentSpecial Rapporteur in paragraph 1 of the article hasdone likewise, even although he appreciates that this mayleave some room for argument as to exactly whatrules of international law institute jus cogens. In manynational systems of law there are well-established cate-gories of unlawful contracts. In international law,however, the time does not seem ripe for trying to codifythe possible categories of " unlawful" treaties. Theappearance of the concept of jus cogens, as alreadyindicated, is comparatively recent, while internationallaw is at a stage of rapid development. Accordingly, theprudent course seems to be to state in general terms therule that a treaty is void if it conflicts with a rule ofjus cogens and to leave the full content of this rule to beworked out in State practice and in the jurisprudence ofinternational tribunals. At the same time, a generaldefinition of a jus cogens rule has been included inarticle 1.4. On the other hand, there may be advantage inindicating, by way of example, some of the more con-spicuous instances of treaties that are void by reason oftheir inconsistency with a jus cogens rule. Paragraph 2,therefore, sets out three such instances. The first, theillegal use of force, hardly needs explanation; the prin-ciples stated in the Charter are generally accepted asexpressing not merely the obligations of Members of theUnited Nations but the general rules of international lawof today concerning the use of force. The second alsospeaks for itself; if a treaty contemplates the perfor-mance of an act criminal under international law, itsobject is clearly illegal. The third instance would alsoseem to be self-evident. Where international law, as in

46 See articles 13 and 14 of the Geneva Convention onthe High Seas, 1958, text in United Nations Conference onthe Law of the Sea, Official Records, vol. II (A/CONF.13/38), United Nations publication, Sales No. 58.V.4, vol. II,annexes, doc. A/CONF. 13/L.53, and articles 5 and 7 of theConvention for the Prevention and Punishment of the Crimeof Genocide 1948, adopted by General Assembly resolution260 (III). Text in United Nations Treaty Series, vol. 78.

the cases of the slave-trade, piracy and genocide,46 placesa general obligation upon every State to co-operate inthe suppression and punishment of certain acts, a treatycontemplating or conniving at their commission mustclearly be tainted with illegality. These instances arenot exhaustive; the words " In particular" at thebeginning of the paragraph indicate that they are merelyparticular applications of the principle that infringe-ments of a jus cogens rule render a treaty void.

5. One point of view might be that any treaty having anillegal object should be totally void and lack all validityuntil reformed by the parties themselves in a way to cureit of the illegality. Having regard, however, to the rela-tionships created by treaty and to the prejudice thatmight result from holding a treaty to be totally void byreason of a minor inconsistency with a jus cogens rule, itseems preferable to allow the severance of illegalprovisions from a treaty in cases where they donot form part of the principal objects of the treaty andare clearly sever able from the rest of its provisions,,

6. Finally, it is to be emphasized that conflict with arule of jus cogens is a ground of invalidity quite inde-pendent of any principle governing the legal effect oftreaties which conflict with prior treaties. True, thejus cogens rule may be one that has been embodied ina prior general multilateral treaty. Under the present ar-ticle, however, the relevant point is not the conflict withthe prior general treaty, but the conflict with a rule havingthe character of jus cogens. The problem of resolvingconflicts between successive treaties dealing with thesame matters may sometimes overlap with the questionof conflict with a jus cogens rule; but the rule in thepresent article is an overriding one of international publicorder, which invalidates the later treaty independently ofany conclusion that may be reached concerning therelative priority to be given to treaties whose provisionsconflict. On the other hand, it would clearly be wrongto consider rules now accepted as rules of jus cogensas immutable and incapable of abrogation or amend-ment in future. Accordingly, paragraph 4 provides thatthe article does not apply to a general multilateral treatywhich expressly abrogates or modifies a rule having thecharacter of jus cogens.

Article 14 — Conflict with a prior treaty

1. (a) Where the parties to two treaties are the same orwhere the parties to a later treaty include all the Statesparties to an earlier treaty, the later treaty is not invali-dated by the fact that some or all of its provisions are inconflict with those of the earlier treaty.

(b) In any such case the conflict between the; twotreaties shall be resolved on the basis of the generalprinciples governing the interpretation and applicationof treaties, their amendment or termination.

2. (a) Where one or a group of the parties to a treaty,either alone or in conjunction with third States, entersinto a later treaty, the later treaty is not invalidated bythe fact that some or all of its provisions are in conflictwith those of the earlier treaty.

(6) In any such case the conflict between the twotreaties shall be resolved —

(i) if the effectiveness of the second treaty is contestedby a State party to the earlier treaty which is not


a party to the later treaty, upon the basis that theearlier treaty prevails;

(ii) if the effectiveness of the second treaty is contestedby a State which is a party to the second treaty,upon the basis of the principles governing theinterpretation and application of treaties, theiramendment or termination.

3. (a) Paragraphs 1 and 2 are without prejudice toany question of invalidity that may arise when the earliertreaty is the constituent instrument of an internationalorganization which contains provisions limiting thetreaty-making powers of its members with respect to theamendment of the constituent treaty or with respect toany particular matters.

(b) In the event of a conflict between the obligationsof the Members of the United Nations under the Charterand their obligations under any other internationalagreement, their obligations under the Charter shallprevail.

4. Paragraphs 1 and 2 shall not be applicable if theprovision of an earlier treaty with which a later treatyconflicts is a provision embodying a rule having thecharacter of jus cogens, in which case article 13 shallapply.

Commentary1. The legal effect of a conflict with a prior treaty, asalready emphasized in the commentary to the previousarticle, is a question which is quite distinct from that ofconflict with a jus cogens rule, even although they mayoverlap when the jus cogens rule is embodied in a generalmultilateral treaty such as the Genocide Convention. Thepresent article, therefore, is concerned exclusively withthe question how far the essential validity of a treatymay be affected by the fact that its provisions conflictwith those of a prior treaty.

2. It is evident that, where the parties to both treatiesare identical, no question of essential validity can nor-mally arise. The States concluding the second treaty arethen fully competent to amend or annul the prior treatyand the problem whether, by reason of the conflict, thesecond treaty modifies or terminates the earlier treaty issimply one of interpreting the provisions of the secondtreaty. The conflict may raise a question of the amend-ment or termination of treaties, but not of essential vali-dity. The position is also broadly the same where theparties to the two treaties are not identical but the partiesto the later treaty include all the parties to the earlierone; since the parties to the earlier treaty are togethercompetent to amend or annul it, they may also do so inconjunction with other States.

3. There are, nevertheless, two classes of case in whichit is conceivable that a question of essential validity mayarise, even although the parties to the two treaties areidentical. One is the case where the earlier treaty is theconstituent instrument of an international organizationand provides that any amendment to it must be effectedexclusively by action taken through organs of the orga-nization. In this type of case it seems that the parties tothe treaty transfer, in part at least, their treaty-makingcapacity with respect to the modification of the consti-tuent treaty to the organization as such. For example,Articles 108 and 109 of the Charter appear to establishspecial constitutional processes for its amendment whichare intended to exclude the normal diplomatic procedure

for amending treaties. In these special processes, twoorgans of the United Nations, the General Assembly andthe Security Council, are given particular roles; at thesame time the classic procedure of ratification by indivi-dual States is retained, but with the difference that anyamendment comes into force for all Members even ifratified only by two-thirds. The possibility that all theMembers of the United Nations might together concludea new diplomatic treaty outside the Organization modify-ing provisions of the Charter is so remote as to make thequestion of the validity of the later treaty somewhatacademic. But the question is by no means so academicin the case of a more limited organization, and has infact been actively debated in connexion with the Euro-pean Community Treaties.47 The Franco-German Agree-ment of 1956 concerning the territory of the Saarresulted in a fundamental change of circumstance neces-sitating some revision of the European Coal and SteelCommunity Treaty, 1951, whereas articles 95 and 96 ofthe Treaty did not contemplate any amendment of itsprovisions during the " Transitional Period", whichwould only terminate in 1958. Although the problem wassolved by the conclusion of a diplomatic treaty directlybetween the member States, it was made plain, at least inthe Netherlands, that this was to be regarded as onlyjustified by the exceptional and unforeseen circumstanceof the transfer of the Saar to Germany; and the Nether-lands Chamber adopted a resolution expressly declaringthat after the end of the transitional period revision ofthe treaty, as also of the other Community Treaties,could only take place through the procedures laid downin the treaties themselves.

4. The other possible case which might arise wouldbe that where an earlier treaty, a constituent instru-ment of an organization, had conferred exclusivetreaty-making powers with respect to particular mattersupon the organization. In such a case it could be saidthat the States concerned had deliberately transferredto the organization, or to certain of its organs, theirtreaty-making capacity with respect to the matters inquestion. Certainly, it seems to have been the view ofall the judges of the Permanent Court, both majorityand minority, in the Austro-German Customs Unioncase 48 that a State which by treaty not merely acceptsrestrictions upon the exercise of powers, but places itselfunder the authority of another State or group of Stateswith respect to those powers, limits to that extent itsown sovereignty and treaty-making capacity.5. The two cases discussed in the preceding paragraphsreally concern limitations upon capacity rather thantreaties invalid by reason of inconsistency with a priortreaty. In the first case, the members of the organizationhave limited their capacity to amend the constitution ofthe organization by subjecting it to particular procedureswithin the organization; in the second case they haveactually transferred a portion of their treaty-makingcapacity to the organization. The precise effect of suchlimitations upon treaty-making capacity may be contro-versial, and to introduce these questions of capacity intothe present article may only complicate an already

47 See Van der Goes van Naters, " La Revision des traitessupranationaux ", Nederlands Tijdschrift voor InternationaalRecht (Liber Amicorum J. P. A. Francois), July 1959, pp.120-131.

Js P.C.I.J., 1931, Series A/B 41, p. 37.

Law of Treaties 55

difficult subject.49 This being so, it is thought sufficientto reserve the point in the present article, withoutprescribing any definite rule. Accordingly, paragraph 1of the article sets out, in sub-paragraphs (a) and (b), thegeneral rules governing this class of case, while para-graph 3 (a) reserves the position in regard to limitationscontained in the constituent instruments of internationalorganizations.6. The main difficulty, however, arises where the par-ties to the later treaty do not include all the States whichwere parties to the earlier one. This may come aboutin two ways: (1) some, but not all, of the parties to atreaty may enter into a second treaty modifying theapplication of the earlier treaty as between each otherbut without consulting the remaining parties to the earliertreaty; or (2) the situation is similar but one or moreoutside States, not parties to the earlier treaty, participatein the second treaty. In either of these cases the secondtreaty may encroach upon the vested rights of otherStates under the earlier treaty and the question is howfar this fact may affect the essential validity of the secondtreaty.

7. Sir H. Lauterpacht's draft (A/CN.4/63 and 87,article 16) provided as the general rule that a treatyshould automatically be void " if its performance involvesa breach of a treaty obligation previously undertaken byone or more of the contracting parties ". He qualified thisprovision by saying that it should only apply " if thedeparture from the terms of the prior treaty is such as tointerfere seriously with the interests of the other partiesto that treaty or substantially to impair an essentialaspect of its original purpose ". He also excepted generalmultilateral treaties altogether from the provision; andin his second report he extended this exception totreaties revising multilateral conventions when concludedby " a substantial majority of the parties to the revisedconvention ". He justified this addition by pointing outin some detail the complications that might otherwisearise in the revision of multilateral conventions andespecially those of a law-making type, where successivetreaties on the same subject with varying parties are acommon enough phenomenon. In support of his pro-posed general rule, Sir H. Lauterpacht cited the dissentingopinions of Judges Van Eysinga and Schiicking in theOscar Chinn case,50 and of Judges Nyholm and Negu-lesco in the European Commission of the Danube case.51

He further explained that this rule proceeded on theassumption that " if parties to a treaty bind themselvesto act in a manner which is a violation of the rights ofa party under a pre-existing treaty, they commit a legalwrong which taints the subsequent treaty with illegality "(A/CN.4/63, article 16, comment, para. 2). This assump-tion he considered to follow from " general principlesof law ", " requirements of international public policy "and " the principle of ̂ rood faith which must be presumedto govern international relations ". " In the internationalsphere ", he said, " the reasons for regarding later incon-sistent treaties as void and unenforceable are even morecogent than in private law ". Although a number ofolder writers, including Oppenheim, provide support forthese views, the majority of writers today do not consider

that a treaty which infringes the rights of other Statesunder prior treaties is necessarily invalid. They holdthat a question of invalidity may arise in particular cases,but that in general the question is rather one of thepriority to be given to conflicting legal provisions.52

8. Sir G. Fitzmaurice's draft (A/CN.4/115, articles 18and 19) was based on the view that in general thequestion is one of reconciling conflicting legal provi-sions and that only in certain types of case may the latertreaty be invalid. His proposals concerning conflictswith prior treaties were somewhat elaborate, and indealing with the main problem he drew a distinctionbetween (1) cases where the parties to the second treatyinclude some only of the parties to the earlier treatyand some additional parties, and (2) cases where theparties to the second treaty include some only of theparties to the earlier treaty but no additional parties.9. In the first class of case, where the parties to thelater treaty comprise some new parties, he consideredthat the later treaty is not invalidated by the conflictand governs the relations between the parties to it; onthe other hand, the earlier treaty prevails over the latertreaty in the relations between any States which areparties to both treaties and States which are parties onlyto the earlier one. States which are parties to bothtreaties may therefore find themselves liable to makereparation to the remaining parties of the earlier treaty,if they do not carry it out; but, if they do carry it out,they may equally be liable to make reparation to theremaining parties of the second treaty, if the latter wereunaware of the conflict when they entered into thesecond treaty. In other words, the conflict raises ques-tions of priority and of legal liability, but not ofvalidity.10. Sir G. Fitzmaurice justified his rejection of the linetaken by the previous Special Rapporteur by citationsfrom certain writers53 and also by the terms ofArticle 103 of the Charter. He pointed out thatArticle 103 does not pronounce the invalidity of treatiesbetween Member States conflicting with the Charter,but only that in the event of a conflict between theobligations o£ Members of the United Nations under the

Charter and their obligations under any other interna-tional agreement, their obligations under the Charterare to prevail. The rationale of Article 103 clearly isthat priority is to be given to the Charter, not thatinvalidity is to attach to a treaty which conflicts withit. The conflicting treaty may be unenforceable, if toenforce it involves a violation of the Charter; but it isnot void. Although this is clearly the effect ofArticle 103, reference to the travaux preparatoires showsthat the Article was drafted primarily with prior treatiesin mind and that Committee IV/2 looked rather toArticle 2, paragraph 2 (the duty of each Member tofulfil in good faith its obligations under the Charter) tocover the case of a Member entering into a subsequenttreaty inconsistent with the Charter. The report of thatCommittee stated: 54 "Concerning the second rule of

49 Previous drafts on the law of treaties have not dealtwith these questions.

50 P.C.I.J. Series A / B , N o . 63, pp . 132-136 and 148-150.5 1 P.C.I.J. Series B / 1 4 , pp . 73 and 129.

52 e.g. C. Rousseau, Principes generaux du droit interna-tional public, p. 341; Lord McNair, op. cit., p. 222; HarvardLaw School, Research in International Law, III, Law ofTreaties, p. 1024.

53 C. Rousseau and the Harvard Research in InternationalLaw.

51 U .N.C . I .O . , Vol . 13, p . 708.


Article 20 of the Covenant, under which Membersundertook not to enter thereafter into any engagementinconsistent with the terms thereof, the Committee hasthought it to be so evident that it would not be necessaryto express it in the Charter, all the more since it wouldrepeat in a negative form the rule expressed in para-graph 2 of Chapter I I 5 5 of the Charter ". Nevertheless,it remains true that Article 103, which is entirelygeneral in its terms and therefore appears to cover bothprior and future agreements, lays down the principleof the priority of the Charter, not that of the invalidityof inconsistent treaties.56

11. The particular question of the effect of the Charterupon a subsequent treaty entered into by a Memberof the United Nations may require further considera-tion. It suffices here to say that the present SpecialRapporteur is in agreement with the position taken bySir G. Fitzmaurice that, where the parties to the secondtreaty include States not parties to the earlier one, thefact that there is a conflict between the two treatiesdoes not render the later one invalid.

12. In the second class of case, where some, but notall, of the parties to a multilateral treaty conclude alater treaty modifying its application as between them-selves, Sir G. Fitzmaurice again adopted as the funda-mental rule the principle that the conflict with the earliertreaty does not render the later treaty invalid. Heconceded that some weighty authorities have taken theview that it is not permissible for a restricted numberof the parties to a treaty to conclude a new treaty onthe same subject, if to do so would impair the obligationcreated by the earlier treaty or be " so inconsistent withthe general purpose of the earlier treaty as to be likelyto frustrate that purpose " (A/CN.4/115, para. 88). Healso noted the view of Judges Van Eysinga and Schuc-king that in the case of a treaty having a quasi-statutory effect and status, providing a constitution,system or regime for an area or in respect of a givensubject, it is not open to any of the parties to enterinto such a later treaty without the consent of all theparties to the earlier one. Nevertheless, he consideredthat there are strong reasons for a more flexible rule.The second treaty is only binding upon the parties to itand does not in law diminish or affect the rights of theother States parties to the earlier treaty. It may do soin fact by undermining the regime of the earlier treatyand this may in some cases raise the question of thevalidity of the second treaty. But there is, in his view,another important consideration pointing the other way:

" The right of some of the parties to a treaty tomodify or supersede it in their relations inter se is oneof the chief instruments, increasingly in use today,whereby a given treaty situation can be changed in adesirable and perhaps necessary manner, in circum-stances in which it would not be possible or wouldbe very difficult to obtain — initially at any rate —the consent of all the States concerned. To forbidthis process — or render it unduly difficult — wouldbe in practice to place a veto in the hands of whatmight often be a small minority of parties opposingchange. In the case of many important groups oftreaties involving a 'chain' series, such as the postal

55 The original designation of Article 2 (2) at the SanFrancisco Conference.

56 See further paragraphs 33-4 of this Commentary.

conventions, the telecommunications conventions, theindustrial property and copyright conventions, thecivil aviation conventions, and many maritime andother technical conventions, it is precisely by suchmeans that new conventions are floated. In some casesthe basic instruments of the constitutions of the orga-nizations concerned may make provision for changesby a majority rule, but in many cases not, so thatany new or modifying system can only be put intoforce initially as between such parties as subscribeto it." {ibid., para. 89).

He also insisted that in cases of this kind it is often quitepossible for the second treaty to be applied as betweenits parties without disturbing the application of theearlier treaty as between them and the other Statesparties to that treaty.

13. On the basis of the above reasoning, the previousSpecial Rapporteur was disinclined ever to regard a latertreaty as invalidated by reason of a conflict with aprevious treaty whose obligations are of a reciprocalkind. However, and with some hesitation, he specifiedtwo cases where the later treaty would be invalidated:

(1) where the earlier treaty expressly prohibits, asbetween any of the parties to it, the conclusion of anytreaty inconsistent with its provisions;

(2) where the later treaty necessarily involves for theparties to it action in direct breach of their obligationsunder the earlier treaty.At the same time, he considered that the position isquite different where the obligations of the earlier treatyare not of a " reciprocating " kind but are of an " inter-dependent " or objective kind. In these cases he providedthat invalidity should be the general rule and dealt withthem in a separate article, which will be examined laterin paragraphs 22-30 of this Commentary.14. The complexity of the proposals of the previousSpecial Rapporteur testify to the difficulty of the problemwith which the present article deals. Sir H. Lauterpachtonly arrived at his comparatively simple set of rules byapplying in the law of treaties what he considered tobe a general principle of law rendering void w contractsto break a contract ". But treaties today serve manydifferent purposes, legislation, conveyance of territory,administrative arrangement, constitution of an interna-tional organization, etc., as well as purely reciprocalcontracts; and, even if it be accepted that the illegalityof a contract to break a contract is a general principleof law — a point open to question — it does not atall follow that the principle should be applied to treatiesinfringing prior treaties. The imperfect state of interna-tional organization and the manifold uses to whichtreaties are put seem to make it necessary for the Com-mission to be cautious in laying down rules whichbrand treaties as illegal and void. This is not to saythat to enter into treaty obligations which infringe therights of another State under an earlier treaty doesnot involve a breach of international law involving legalliability to make redress to the State whose rights havebeen infringed. But it is another thing to say that thesecond treaty is void for illegality and a complete nullityas between the parties to it.

15. The attitude adopted by the Permanent Court inthe Oscar Chinn and European Commission of theDanube cases hardly seems consistent with the existence

Law of Treaties 57

in international law of a general doctrine invalidatingtreaties entered into in violation of the provisions of aprior treaty. In the Oscar Chinn case57 the earliertreaty was the General Act of Berlin of 1885, whichestablished an international regime for the Congo Basin.That treaty contained no provision authorizing theconclusion of bilateral arrangements between particularparties; on the contrary it contained a provision expresslycontemplating that any modification or improvementof the Congo regime should be introduced by " commonaccord " of the signatory States. Nevertheless, in 1919certain of the parties to the Berlin Act, withoutconsulting the others, concluded the Convention ofSt. Germain whereby, as between themselves, they abro-gated a number of the provisions of the Berlin Act, re-placing them with a new regime of the Congo. The Courtcontented itself with observing that, no matter whatinterest the Berlin Act might have in other respects, theConvention of St. Germain had been relied on by boththe litigating States as the source of their obligations andmust be regarded by the Court as the treaty which itwas asked to apply. Admittedly, the question of thelegality of the Convention of St. Germain had not beenraised by either party. But the question was dealt withat length by Judges Van Eysinga and Schiicking indissenting judgements and had, therefore, evidently beendebated within the Court. Moreover, these Judges hadexpressly taken the position that the question of thevalidity or invalidity of the treaty was not one whichcould depend on whether any Government hadchallenged its legality, but was a question of publicorder which the Court was bound itself to examine exofficio. In these circumstances, it is difficult to interpretthe Court's acceptance of the Convention of St. Ger-main as the treaty which it must apply, as anythingother than a rejection of the doctrine of the absoluteinvalidity of a treaty which infringes the rights of thirdStates under a prior treaty.16. The line taken by the Court in its advisory opinionon the European Commission of the Danube58 wasmuch the same. The Versailles Treaty contained certainprovisions concerning the international regime for theDanube, including provisions concerning the composi-tion and powers of the European Commission for thatriver; at the same time it looked forward to the earlyconclusion of a further Convention establishing a defini-tive statute for the Danube. A further Convention wasduly concluded, the parties to which did not compriseall the parties to the Treaty of Versailles but did includeall the States which were concerned in the disputegiving rise to the request for the advisory opinion. Inthis case the question of the capacity of the States atthe later conference to conclude a treaty modifyingprovisions of the Treaty of Versailles was raised in thearguments presented to the Court, which pronouncedas follows:

" In the course of the present dispute, there hasbeen much discussion as to whether the Conferencewhich framed the Definitive Statute had authority tomake any provisions modifying either the composi-tion or the powers and functions of the EuropeanCommission, as laid down in the Treaty of Versailles,and as to whether the meaning and the scope of the

relevant provisions of both the Treaty of Versaillesand the Definitive Statute are the same or not. Butin the opinion of the Court, as all the Governmentsconcerned in the present dispute have signed andratified both the Treaty of Versailles and the Defi-nitive Statute, they cannot, as between themselves,contend that some of its provisions are void as beingoutside the mandate given to the Danube Conferenceunder Article 349 of the Treaty of Versailles." 59

Here again, it is difficult not to see in the Court's pro-nouncement a rejection of the doctrine of the absoluteinvalidity of a later treaty which infringes the rights ofthird States under a prior treaty.60 The MavrommatisPalestine Concessions case 61 was, it is true, a somewhatdifferent type of case, but it also appears to proceed ona basis quite inconsistent with the idea that a latertreaty will be void to the extent that it conflicts with anearlier multilateral treaty.

17. In its advisory opinion on the Austro-GermanCustoms Union 62 the Court was only called upon toconsider the compatibility of the Protocol of Viennawith the Treaty of St. Germain; it was not asked topronounce upon the legal consequences in the event ofits being found incompatible with the earlier treaty. Intwo cases concerning Nicaragua's alleged violation ofthe prior treaty rights of Costa Rica and Salvador byconcluding the Bryan-Chamorro Treaty with the UnitedStates, the Central American Court of Justice considereditself debarred from pronouncing upon the validity ofthe later treaty in the absence of the United States overwhich it had no jurisdiction. It therefore limited itselfto holding that Nicaragua had violated its treaty obliga-tions to the other two States by concluding a laterinconsistent treaty with the United States.63

18. International jurisprudence is not perhaps entirelyconclusive on the question whether and, if so, in whatcircumstances a treaty may be rendered void by reasonof its conflict with an earlier treaty. Nevertheless, itseems to the present Special Rapporteur strongly todiscourage any large notions of a general doctrine ofthe nullity of treaties infringing the provisions of earliertreaties;64 and it accordingly also lends point to thehesitations of Sir G. Fitzmaurice in admitting any casesof nullity where the conflict is with an earlier treaty ofa " mutual reciprocating type ".19. The two cases of nullity tentatively suggested byhim (see paragraph 13 above), although they aresupported by the Harvard Research Draft, hardly seemconsistent with the attitude of the Court in the OscarChinn and European Commission of the Danube cases.In the former case there was an express stipulation that

« P.C.I.J., Series A / B , No . 63.5 8 P.C.I.J. Series B, No . 14.

59 P.C.I.J., Series B, No . 14, p . 23.60 The more so as two Judges, Nyholm and Negulesco,

took a different line from the Court, holding that any pro-vision of the Statute which conflicted with the Treaty of Ver-sailles would be " null "; P.C.I.J., Series B, No . 14, pp. 73and 129.

61 P.C.I.J.. Series A, No . 2.62 Ibid., Series A/B, No. 41.63 American Journal of International Law, vol. II (1917),

pp. 228 and 729.64 See G. Schwarzenberger, op. cit., pp. 48?.-7; and see

also article 18 of the Havana Convention of 1928 on Treaties{Harvard Research in International Law, p. 1207) which pro-vided: " Two or more States may agree that their relationsare to be governed by rules other than those establishedin general conventions concluded by them with other States."


any modifications of the Berlin Act should be by" common accord "; yet the Court considered it sufficientthat no State had challenged the Convention of St. Ger-main. It does not seem that the Court would haveadopted any different view, if the stipulation had takenthe form of an express prohibition against contractingout of the treaty otherwise than by " common accord ".It is also arguable that there is implied in every multi-lateral treaty an undertaking not to violate its provisionsby entering into inconsistent bilateral agreements.Accordingly, it hardly seems justifiable to provide, as aspecial case, that a later treaty shall be void if it conflictswith a prior treaty which contains an express prohibi-tion against inconsistent bilateral agreements. An under-taking in a treaty not to enter into a conflicting treatydoes not, it is thought, normally affect the treaty-makingcapacity of the States concerned, but merely places themunder a contractual obligation not to exercise theirtreaty-making powers in a particular way. A breach ofthis obligation engages their responsibility; but the latertreaty which they conclude is not a nullity. Similarly,if the general view be adopted — as it was by theprevious Special Rapporteur — that a later treatyconcluded between a limited group of the parties to amultilateral treaty is not normally rendered void bythe fact that it conflicts with the earlier treaty, his secondtentative exception to the rule does not appear tojustify itself. This exception concerned cases where thelater treaty " necessarily involves for the parties to itaction in direct breach of their obligations under theearlier treaty ". The question of nullity does not ariseat all unless the later treaty materially conflicts withthe obligations of the parties under the earlier treaty.Can it make any difference whether the infringementof those obligations is direct or indirect, if it is thelogical effect of the later treaty? Of course, if the latertreaty is susceptible of different interpretations or iscapable of performance in different ways, it may notbe possible to know whether there is any conflict withthe earlier treaty until the later treaty has been inter-preted and applied by the States concerned. But if itis in fact interpreted and applied in a manner whichviolates the earlier treaty, can it reasonably be differen-tiated from a treaty whose terms unambiguously violatethe earlier treaty?

20. On balance, and especially because of the consi-derations advanced by Sir G. Fitzmaurice with regardto " chain " multilateral treaties, the present SpecialRapporteur suggests that the safest course for the Com-mission to adopt is not to prescribe nullity in any casewhere the earlier treaty is of a type involving reciprocalobligations. In other words, it should recognize thepriority of the earlier treaty but no more. A party toit which enters into a later inconsistent treaty cannot" oppose " the later treaty to any party to the earliertreaty which is not also a party to the later one. A Stateparty to both treaties may find its international respon-sibility engaged by the mere conclusion of the latertreaty or by its application in a manner violating theearlier treaty; but the inconsistency does not make thelater treaty null and void in law.

21. Accordingly, paragraph 2 of the present articledoes not make provision for the two cases of invalidityformulated — with much hesitation — by the previousSpecial Rapporteur. It states without qualification in sub-

paragraph (a) that in general a later treaty is not inva-lidated by the fact of its inconsistency with a priortreaty; and in sub-paragraph (b) it lays down that inthe relations between any State which is a party to bothtreaties and a State which is a party to the first treatyonly it is the provisions of the first treaty which prevail.22. Finally, it is necessary to consider the cases inwhich the previous Special Rapporteur proposed (A/CN.4/115, article 19) that the general rule should bethe nullity of the later treaty. These are cases where theearlier treaty is a multilateral treaty creating rights andobligations which are not of a " mutually reciprocatingtype " but are either —

(a) of an " interdependent type where a fundamentalbreach of an obligation by one party will justify a corre-sponding non-performance generally by the other partiesand not merely in their relations with the defaultingparties "; or

(b) of an " integral type where the force of the obliga-tion is self-existent, absolute and inherent for each party,and not dependent on a corresponding performance bythe others ".In either of these cases the rule proposed in the draftwas that " any subsequent treaty concluded by any twoor more of the parties, either alone or in conjunctionwith third countries, which conflicts directly in amaterial particular with the earlier treaty will, to theextent of the conflict, be null and void ". This exception,therefore, was to apply not only to the class of casewhere a group of the parties to the earlier treaty concludea later, inconsistent, treaty but also to the other classof case where some of the parties to the earlier treatyplus some outside States conclude a later, inconsistenttreaty.23. Sir G. Fitzmaurice's division of treaties into threedistinct types requires further explanation. Treaties of a" mutually reciprocal " type, as might be supposed, are" do ut des " treaties in which each party owes to eachother party certain obligations and obtains in returncorresponding rights from that party; in other words, thetreaty, although multilateral, sets up what are essentiallybilateral relationships. The Vienna Convention onDiplomatic Relations 65 is an example of this type oftreaty, which has already been discussed in the precedingparagraphs; a later treaty is not to be considered voidby the fact that it conflicts with such a treaty. An " inter-dependent type ", on the other hand, is one where theobligations and rights of each party are only meaningfulin the context of the corresponding obligations andrights of every other party; so that the violation of itsobligations by one party prejudices the treaty regimeapplicable between them all and not merely the relationsbetween the defaulting State and the other parties.Examples given by the previous Special Rapporteurwere treaties of disarmament, treaties prohibiting the useof particular weapons, treaties requiring abstention fromfishing in certain areas or during certain seasons, etc.The Antarctic Treaty 66 declaring that Antarctica is to be

65 United Nations Conference on Diplomatic Intercourseand Immunities, Vienna, 2 March-14 April 1961, OfficialRecords, vol. II (A/CONF. 20/14/Add.l), United Nationspublication, Sales No. 62.XI.1, p. 82, document A/CONF.20/13 and Corn 1.

66 Signed in Washington on 1 December 1959; text inUnited Nations Treaty Series, vol. 402, p. 71.

Law of Treaties 59

" used for peaceful purposes only " and prohibiting " anymeasures of a military nature " would presumably beanother example of the same kind. The third, " integ-ral ", type was defined by the previous Special Rappor-teur as comprising treaties where the force of the obliga-tion is " self-existent, absolute and inherent for eachparty and not dependent on a corresponding perfor-mance by the others ". The examples given by him werethe Genocide Convention, Human Rights Conventions,the Geneva Conventions of 1949 on prisoners ofwar,67 etc., International Labour Conventions andtreaties imposing an obligation to maintain a certainregime or system in a given area, such as the regime ofthe Sounds and the Belts at the entrance to the BalticSea.

24. The reason which led the previous Special Rappor-teur to distinguish " interdependent " and " integral "types of treaty from " mutually reciprocating " typesand to propose the avoidance of later treaties conflictingwith the two former types of treaty are easily under-stood. The conclusion of a conflicting treaty in the twoformer cases undermines the treaty regime betweenall the parties, whereas in the case of mutually reci-procating types is does not. The same reason led him todifferentiate in a similar way between these types oftreaty in his treatment of the termination of treaties onthe ground of fundamental breach. Nevertheless, theproposal to avoid later treaties which conflict with" interdependent " or " integral " types of treaty requiresvery careful examination. As already stressed in para-graph 14, it is necessary for the Commission to be verycautious in prescribing the nullity of treaties concludedbetween sovereign States.

25. The first point for consideration is the relationbetween the proposed rule avoiding treaties for inconsis-tency with an " interdependent " or " integral " type oftreaty and the rule avoiding treaties for conflict with ajus cogens rule. For example, the Genocide Conventionand the Geneva Conventions of 1949 would clearly seemto fall under the article avoiding treaties for conflictwith a jus cogens rule. Moreover, in the case of theGeneva Conventions of 1949, there is a certainawkwardness in holding the later treaty void simply onthe ground of its conflict with the Conventions, '' integ-ral type " though they may be. For each one of thesemajor humanitarian Conventions contains an expressprovision 68 stating that each one of the High Contract-ing Parties shall be at liberty to denounce the Conven-tion, the denunciation to take effect one year afterits notification. True, there is also a proviso that adenunciation made at a time when the party concernedis engaged in a conflict shall not take effect until afterthe application of the Conventions with respect to thatconflict is ended. But otherwise the liberty to denouncethe Conventions in complete, and this, to say the least,seriously weakens the case for holding a later bilateraltreaty void simply on the ground of inconsistency witha prior " integral type " treaty. On the other hand, thefundamental principles which are enshrined in theConventions are principles of a jus cogens character,

from which a State cannot release itself even bydenouncing the treaties, as is indeed expressly pointedout in the articles providing for denunciation. Para-graph 4 of these articles states: " The denunciation shallhave effect only in respect of the denouncing Power. Itshall in no way impair the obligations which the partiesto the conflict shall remain bound to fulfil by virtue ofthe principles of the law of nations, as they result fromthe usages established among civilized peoples, fromthe laws of humanity and the dictates of the publicconscience ". In others words, it seems to the presentSpecial Rapporteur that it is the jus cogens nature ofthe subject-matter of these Conventions, rather than the" integral " character of the obligations created by theConventions upon which the nullity of an inconsistentlater treaty has to rest. It may be added that a largenumber of these so-called " integral " type treaties havewithdrawal or denunciation clauses.69 Even the GenocideConvention (article 14) provides for the possibility ofunilateral denunciation at regular intervals every fiveyears; but here again denunciation of the Conventionwould not absolve a State from observing its funda-mental principles.

26. Another point is that " interdependentw and" integral " type obligations may vary widely in theircharacter and importance. Some, although importantor useful enough in their own sphere, may be essentiallytechnical; while others deal with matters vital to thewell-being of peoples, such as the maintenance of peaceor the suppression of the traffic in women or narcotics.If the question of the nullity of inconsistent treaties isput — as it is by the previous Special Rapporteur —upon the illegality of the object of any treaty whichconflicts with an " integral " or " interdependent " typeobligation, the effect is almost to convert these obliga-tions into jus cogens rules — at any rate so long asthe treaty has not been denounced. It may be that inter-national law will come to recognize " interdependent "or " integral " type obligations contained in multilateraltreaties as having the force of jus cogens for the parties;but so long as such a wide freedom of denunciation,and indeed of reservation, exists in regard to many ofthese treaties, it scarcely seems possible to regard themin that way. Nor is it clear that a treaty derogatingfrom an " interdependent " type obligation will neces-sarily tend to disrupt the whole regime. If two Stateswere to agree to suspend as between themselves a treatyforbidding the discharge of oil into the sea, the agree-ment would, no doubt, violate an " integral type"obligation, but for geographical reasons it might wellbe that they themselves would be the only partiesmaterially affected by the violation, or at worst theyand a third neighbouring State. Again, some treatieswhich establish a general regime for a given area involvea recognition of rights and not merely an abstentionfrom certain acts; and then, although the treaties are inprinciple of an " integral " type, denial of the right toone State may not materially weaken the general regime.

27. Some treaties which establish " interdependent"or " integral " type obligations also contain " mutuallyreciprocating " obligations. The Antartic Treaty indeed

67 In ternat ional Commit tee of the Red Cross, The GenevaConventions of 12 August 1949, Geneva.

68 E.g. article 63 of the Geneva Convent ion for the A m e -lioration of the condition of the wounded and sick in A r m e dForces in the Field.

69 See the Uni ted Nat ions " Handbook of Final Clauses "(ST/LEG/6), pp. 59-73.


contains obligations of all three types: Articles 1 and 5,which prohibit respectively measures of a military natureand nuclear explosions, are of an " interdependent "type; article 2, which provides for " freedom of scien-tific investigation ", is of an " integral " type, though itmay involve some element of " reciprocating " obliga-tion; article 3, which provides for free exchange of infor-mation, is of a " mutually reciprocating " type, whilearticle 4, which reserves the existing legal positions ofStates with regard to territorial claims and forbids themation, is of a " mutually reciprocating " type, whilethe treaty is in force, is perhaps a mixture of '' inter-dependent " and " mutually reciprocating " obligations;article 7, which concerns the right to appoint observers,inspect stations etc., is purely of a " reciprocating " type,yet it is vital to the effectiveness of some of the " inter-dependent " obligations; article 8 is again, perhaps, amixture of " interdependent " and " mutually recipro-cating " obligations. The Antarctic Treaty thus illustratesvery clearly how mixed may be the types of obligationin a single treaty; and a similar mixture can be seenin other treaties, for example treaties for the regulationof fisheries. It may also be noted that some internationalregimes created by treaty are regional in character,others universal.

28. The Permanent Court, it has been pointed outabove {supra, paragraphs 15-16), refused in the OscarChinn case and again in the European Commission forthe Danube case to discard as a nullity a treaty dero-gating from a prior treaty, despite the powerful argumentin favour of the contrary view adduced by a smallminority of dissenting judges. In both these cases theprior treaty was a multilateral treaty establishing for aparticuW region an international regime which containedobligations of an " integral " or " interdependent " type.In both cases the special character of the treaty wasemphasized by the dissenting judges, yet the Court wouldnot look beyond the fact that the disputing States werethemselves parties to the later treaty and had notchallenged its validity. In the Mavrommatis PalestineConcessions case the position was somewhat differentin that the later treaty, a Protocol, extended, rather thanderogated from, the earlier treaty and it was GreatBritain, a party to both treaties, that challenged theapplication of the Protocol. Nevertheless, in that casealso the earlier treaty was one establishing an interna-tional regime — a Mandate — and the Court wasemphatic that, in case of conflict, the provisions of thelater treaty should prevail.

29. The jurisprudence of the Permanent Court there-fore, so far as it goes, seems to be opposed to the ideathat a treaty is automatically void if it conflicts with anearlier multilateral treaty establishing an internationalregime. Where the States before the Court were allparties to the later treaty, the Court applied the latertreaty. This does not, of course, mean that the Per-manent Court would not, in an appropriate case, haveconsidered a later treaty which derogated from an earliermultilateral treaty to be a violation of the rights ofthe States parties to the earlier treaty who were not alsoparties to the second treaty. But it does seem to meanthat the Permanent Court acted on the principle thatconflicts between treaties are to be resolved on thebasis of the relative priority of conflicting legal norms,not on the basis of the nullity of the later treaty; and

acted on that principle even when the prior treaty wasan international " statute " creating an internationalregime. Admittedly, the law of treaties has undergoneconsiderable development during the past thirty years,and there is a greater disposition to recognize the objec-tive effects of certain kinds of treaties. But it may bedoubted whether this development has gone so far asto recognize that a treaty will be void to the extentthat it conflicts with any earlier mulilateral treaty estab-lishing " interdependent " or " integral " obligations.Indeed, the important consideration to which theprevious Special Rapporteur drew attention in regard to'' chain " treaties is enough to induce hesitation on thisquestion. Multilateral treaties creating " interdependent "obligations or international regimes are the very classesof treaty in which a " chain " series of instruments maybe found;70 and it will more often than not be the casethat some parties to the earlier treaties fail for onereason or another to become parties to the later treaties.No doubt, it might be possible to try and cover thisdifficulty by a complicated formula excepting " chain "treaties from the penalty of invalidity. But it seems saferfor the Commission, in the present state of the develop-ment of international law, to hold to the general linetaken by the Permanent Court on this question.

30. Accordingly, while recognizing the general signi-ficance of the distinctions made by Sir G. Fitzmaurice,the present Special Rapporteur considers it preferablethat the nullity of a treaty by reason of its inconsistencywith an earlier multilateral treaty should not be predi-cated by the Commission as the general rule even whenthe earlier treaty is of an " interdependent " or " integ-ral " type. Article 14 does not, therefore, make anydistinction between treaties of an " interdependent " or" integral " type and other treaties, but places all typesunder the same rule in paragraph 2 (a), which goes uponthe principle that conflict with an earlier treaty is notnormally a ground of nullity.

31. Paragraph 2 (b) sets out the general rules forresolving conflicts between two treaties, when the partiesto the later treaty do not include all the parties to theearlier one. It specifies two different rules accordingto whether the interests of a State which is a party tothe first treaty but not to the second are involved. Ifso, since the parties to the second treaty are incompetentto deprive it of its rights under the first treaty, theearlier treaty prevails. If not, the question is one ofthe interpretation and application of treaties, and oftheir amendment or termination by subsequent agree-ment; and, as the jurisprudence of the Permanent Courtindicates, the later treaty is likely to prevail in mostcases.

32. Paragraph 3 (a) of the article, as previously in-dicated in paragraph 5 of this Commentary, draws atten-tion to the case of the constituent instrument of interna-tional organizations which may contain provisionsarguably affecting the capacity of members to enter intocertain kinds of treaty. This being a question of capacity,not invalidity, which belongs to the law of internationalorganizations, article 14 merely notes and reserves thepoint.

70 Sir H. Lauterpacht also modified paragraph 4 of hisdraft article on this very ground (A/CN.4/87, article 16).

Law of Treaties 61

33. Paragraph 3 (b) repeats the provision containedin Article 103 of the Charter. This provision has alreadybeen mentioned in paragraph 10 of this Commentary,where it was pointed out that Article 103 appears to bebased upon the principle of the priority of the Charterrather than upon that of the invalidity of inconsistenttreaties. At the same time it was noted that the Articlehad been phrased primarily with pre-existing inconsistenttreaties in mind and that it seems to have been con-sidered at San Francisco that the conclusion of asubsequent inconsistent treaty would be a violation ofArticle 2, paragraph 2, by which Members undertaketo fulfil in good faith the obligations assumed by them inthe Charter. Within the United Nations the applicationof Article 103 has been discussed principally in connex-ion with the work of the Collective Measures Committeeand with the relation between the Charter and the SanFrancisco Statement on Voting Procedure in the SecurityCouncil, though Article 103 has also been raised inconnexion with one or two particular disputes. None ofthe discussions throw much light, however, on the ques-tion whether a later inconsistent treaty concluded by Mem-bers is to be regarded as void or merely a violation of theirobligations under the Charter.71 Despite the fact thatArticle 103 itself only provides that the obligations ofthe Charter shall " prevail ", one eminent authority 72

has expressed the view " that those of its provisionswhich purport to create legal rights and duties possess aconstitutive or semi-legislative character, with the resultthat Member States cannot 'contract out' of them or dero-gate from them by treaties made between them, and thatany treaty whereby they attempted to produce this effectwould be void ". The same authority further explained "that, in his view, Members of the United Nations " byacceptance of the Charter, a constitutive instrument, haveaccepted a limitation of their treaty-making capacity ".

34. The Special Rapporteur does not think that theCommission need or ought to take a position upon thegeneral question of the effect of Article 103, whichconcerns the effect of a constituent treaty upon thetreaty-making capacity of members of an organizationvis-a-vis the organization. It is a question which isessentially one of the interpretation of the Charter andof the law of international organizations, and whichtherefore falls under the reservation of this questioncontained in paragraph 3 (a) of this article. Moreover,it is not the function of the Commission to render inter-pretations of the Charter. On the other hand, Article 103lays down a rule which is of fundamental importance inregard to conflicts between treaties and, therefore,requires to be incorporated in some form in the article.The appropriate course, for the reasons just given, seemsto be to reproduce, as has been done in paragraph 3 (b),the actual provision contained in Article 103.

35. Paragraph 4, simply for formal reasons of drafting,excepts from the operation of paragraphs 1 and 2 trea-ties which, conflict with a jus cogens rule that is embodiedin a prior treaty and makes them subject to article 13.

71 Repertory of Practice of United Nations Organs, Vol. V,pp. 315-20.

72 Lord McNair, op. cit., p. 217." Ibid., p. 218.

SECTION III — THE DURATION, TERMINATION ANDOBSOLESCENCE OF TREATIES

Article 15 — Treaties containing provisions regardingtheir duration or termination

1. Subject to articles 18-22, the duration of a treatywhich contains provisions either regarding its durationor termination shall be governed by the rules laid downin this article.

2. In the case of a treaty whose duration is expressedto be limited by reference to a specified period, date orevent, the treaty shall continue in force until the expiryof the period, passing of the date or occurrence of theevent prescribed in the treaty.

3. In the case of a bilateral treaty which is expressedto be subject to denunciation or termination upon notice,whether a notice taking effect immediately or after astated period, the treaty shall continue in force until anotice of denunciation or termination has been given byone of the parties in conformity with the terms of thetreaty and has taken effect.

4. (a) In the case of a multilateral treaty which isexpressed to be subject to denunciation or withdrawalupon notice, whether a notice taking effect immediatelyor after a stated period, the treaty shall continue in forcewith respect to each party until that party has given anotice of denunciation or withdrawal in conformity withthe terms of the treaty and that notice has taken effect.

(b) The treaty itself shall terminate in accordancewith paragraph 2 if the number of the parties shouldat any time fall below a minimum number laid down inthe treaty as necessary for its continuance in force.

(c) The treaty shall not, however come to an end byreason only of the fact that the number of the partiesshall have fallen below the minimum number of partiesoriginally specified in the treaty for its entry into force,unless the States still parties to the treaty shall so decide.

5. (a) In the case of a treaty which both expresslylimits its duration and provides for a right to denounceor withdraw from it upon notice, the treaty shall continuein force with respect to each party until either the treatyshall have expired under paragraph 2, or the party inquestion shall have denounced or withdrawn from thetreaty under paragraph 3 or 4, whichever event shallfirst occur.

(b) If a treaty, whose duration is expressed to belimited by reference to a specifed period, date orevent, provides that, unless denounced before the expiryof the period, passing of the date or arrival of theevent, the treaty shall automatically be prolonged fora further period or periods, it shall continue in forceuntil the expiry of the further period or periods,except with regard to any party which has denouncedit in accordance with the terms of the treaty.If the length of the further period should not have beenspecified in the treaty, it shall be the same as that of theperiod prescribed for the initial duration of the treaty.

6. The rules stated in the preceding paragraphs shallalso apply where the conditions of the duration or ter-mination of a treaty have been fixed not in the treatyitself but in a separate related instrument.


Commentary1. A great many modern treaties contain clauses eitherfixing their duration or providing for a right to denounceor withdraw from the treaty. When this is so, the dura-tion and termination of the treaty are regulated by thetreaty itself and the question is simply one of the inter-pretation and application of its terms. Nevertheless, thetreaty clauses take a variety of forms,74 and it seemsdesirable that the draft articles should set out the mainrules by which the duration of treaties is determinedunder these clauses. As paragraph 1 states, these rulesare set out in paragraphs 2-6 of this article, the case oftreaties which contain no provisions on the questionbeing left to the next article.2. Most treaties today provide that they are to remainin force for a specified period of years or until a parti-cular date or event. Clearly in such cases the treaty will,in principle, cease automatically upon the expiry of theperiod, the passing T5 of the date, or the occurrence ofthe event prescribed in the treaty; and this is so statedin paragraph 2 (a). The periods fixed by individualtreaties vary enormously, periods between one andtwelve years being the commonest but longer periodsof up to twenty, fifty and even ninety-nine years beingsometimes found. As to terminating events, one of thetypes most frequently found in practice is a provisionthat the treaty shall cease to have effect if the partiesfall below a prescribed number.76

3. Some bilateral treaties fix no specific limit to theirduration but provide for a right to denounce or terminatethe treaty either with or without notice. For example, ar-ticle 5 of a recent Agreement77 between the United King-dom and Portugal for the avoidance of double taxationprovides: " This Agreement shall continue in force inde-finitely but may be terminated by either ContractingParty by giving six months' notice to the other Contract-ing Party ". When the treaty does fix a specific periodfor its duration, such as five or ten years, it may at thesame time provide for a right of denunciation upon sixor twelve months' notice during the period, though thisis unusual. Far more frequent is a provision continuingsometimes found. As to terminating events, one of theinitial period, subject to a right in either party to de-nounce the treaty immediately or after some specifiedperiod of notice. The exercise of a right of terminationor denunciation by one of the parties in the case of abilateral treaty necessarily puts an end to the wholetreaty. Paragraph 3 of the article is accordingly soworded as to make the treaty itself come to an endwhen a valid notice given by either of the parties hastaken effect.4. Similarly, multilateral treaties, which fix no specificlimit to their duration, may provide for a right todenounce or withdraw from the treaty. That is the case,for example, with the Geneva " Red Cross " Conven-tions of 1949. Indeed, it is almost common form todayfor multilateral treaties to be made terminable either

upon denunciation of, or withdrawal from, the treaty.In many cases, even when the treaty is expressed to beentered into for a specific period, it is made to continuethereafter, subject to a right in each party to denounceor withdraw from the treaty. This is done either bystating that it shallcontinue in force indefinitely, subjectto the right of denunciation or withdrawal, or by statingthat it shall be perpetually renewable for further succes-sive periods of years, with a right in each party todenounce or withdraw from it shortly before the end ofeach successive period. The two types of provision arenot very different in their results, the main differencebeing that in the latter type the exercise of the right ofdenunciation or withdrawal is exercisable only atregular intervals. Nevertheless, it is thought more con-venient to deal with the " renewable " type of treaty underparagraph 5, and paragraph 4 is intended to cover onlythose multilateral treaties which, either from the outsetor after an initial specific period, are expressed to con-tinue indefinitely, unless terminated by denunciation orwithdrawal (see further paragraph 8 below).5. Paragraph 4 (a) lays down the general rule formultilateral treaties. Here, denunciation or withdrawalby one party does not normally terminate the treaty itself,but only its application to that particular party. Accord-ingly the general rule is expressed to be that the treatysubject to denunciation or withdrawal, does provide fordenunciation or withdrawal given by it has taken effect.6. Sometines, however, a multilateral treaty, which issubject to denunciation or withdrawal, does provide forthe termination of the treaty itself, if denunciations orwithdrawals should reduce the number of parties belowa certain figure. For example, the Convention on thePolitical Rights of Women 78 provides that it " shallcease to be in force as from the date when the denuncia-tion which reduces the number of parties to less thansix becomes effective ". In some cases the minimumnumber of surviving parties required by the treatyto keep it alive is even smaller, e.g., five in thecase of the Customs Convention on the TemporaryImportation of Commercial Road Vehicles79 andthree in the case of the Convention Regarding theMeasurement and Registration of Vessels Employed inInland Navigation.80 These cases are covered in para-graph 4 (b).7. In this connexion, the further point arises whethera multilateral treaty, the entry into force of which wasmade dependent upon its ratification, acceptance, etc.,by a given minimum number of States, automaticallyceases to be in force, should the parties afterwards fallbelow that number as a result of denunciations or with-drawals. The better opinion,81 it is believed, is that thisis not a necessary effect of a drop in the number of theparties below that fixed for the treaty's entry into force.The treaty provisions in question relate exclusively to theconditions for the entry into force of the treaty and, ifthe negotiating States had intended the minimum numberof parties fixed for that purpose to be a continuingcondition of the validity of the treaty, it would have

74 See Uni ted Nat ions Handbook of Final Clauses ( S T /L E G . 6), pp . 55-73.

75 It is the passing rather than the arrival of the datewhich is relevant since the treaty will expire at midnight onthe date fixed by the treaty.

76 See United Nat ions Handbook of Final Clauses, pp . 57,58, 72 and 73 .

77 (1961) H.M. Stationery Office, C m n d . 1873.

78 United Nations Treaty Series, vol. 193, p. 135, art. 8.79 United Nations Handbook of Final Clauses, p. 58.80 Ibid., pp. 72-3.81 See E. Giraud, " Modification et terminaison des traites

collectifs " Annuaire de Vlnstitut de droit international,tome I, 1961, p. 62.

Law of Treaties 63

been both easy and natural for them so to provide. Insome cases, it is true, a treaty which fixes a low mini-mum number of parties for entry into force prescribesthe same number for the cessation of the treaty. Butthere is no general practice to that effect, and the factthat this has not been a regular practice in cases wherea larger minimum number, such as ten or twenty, hasbeen fixed for entry into force seems significant. At anyrate, when the number for entry into force is of thatorder of magnitude, it does not seem desirable that theapplication of the treaty should be dependent on thenumber of parties not falling below that number.Moreover, the remaining parties, if unwilling to continueto operate the treaty with the reduced number, maythemselves either join together to terminate it orseparately exercise their own right of denunciation orwithdrawal. Accordingly, paragraph 4 (c) lays downthat the validity is not affected by the mere fact that thenumber of its parties falls below that prescribed forits original entry into force.8. Paragraph 5 (a) covers the possible, if unusual, casewhere a treaty lays down a specific period for its durationbut nevertheless allows denunciation during the currencyof the period. It also covers the case discussed in theprevious paragraph where the treaty provides that eachparty shall have the right to denounce it and that it shallterminate upon the number of parties being reducedbelow a certain number. The application of the treatymay then terminate for an individual party eitherbecause it has itself exercised its right of denunciationor because the terminating event has occurred throughthe acts of other parties.9. Paragraph 5 (b) covers the case of renewable trea-ties, which are today extremely common. When a treaty,especially a multilateral treaty, lays down a compara-tively short period of years for its duration, it veryfrequently provides for its own renewal for a furtherperiod or periods of years; indeed, in most cases itprovides for its indefinite continuance in succeedingperiods of years. At the same time, however, it conferson each party a right to denounce or withdraw fromthe treaty on giving reasonable notice prior to the com-mencement of each new period. A typical example ofthis type of clause is article 14 of the Genocide Conven-tion,82 which reads:

" The present Convention shall remain in effect fora period of ten years as from the date of its cominginto force.

" It shall thereafter remain in force for successiveperiods of five years for such Contracting Parties ashave not denounced it at least six months before theexpiration of the current period."

One authority 83 has observed that this type of formuladoes not really convert the treaty into one for a limitedterm; for the treaty will continue indefinitely for succes-sive periods of years. Thus, from the point of view ofsubstance, the formula is rather a method of regulatingthe exercise of the right of denunciation than of provid-ing for the renewal of the treaty for successive terms.This is, of course, true, and it could be argued that this

82 United Nations Treaty Series, vol. 78, p. 277; cf. alsoarticle 36 of the Convention of 1955 establishing an Inter-national Organization of Legal Metrology.

83 E. Giraud, op. cit., pp. 42-43.

type of treaty really falls under paragraphs 3 and 4,which deal with treaties reserving a right of denuncia-tion. But since the parties have chosen to express theduration of the treaty as one of successive terms of yearsand have linked the power of denunciation specifically tothe dates of the expiry of each successive term, it seemsperhaps to be more in accordance with their intentionsto deal with this type of treaty under paragraph 5 as aspecial case of a time-limit combined with a denuncia-tion clause. Paragraph 5 (b) accordingly covers this typeof case by providing that the treaty is to continue inforce for each party until the expiry of the further periodor periods, except with regard to any party that mayhave exercised its right of denunciation.10. Paragraph 6 is a formal article the reason forwhich is that in some cases it may happen that theprovisions concerning the duration or termination of atreaty are not contained in the treaty itself but in acontemporaneous or collateral protocol or other suchinstrument.

Article 16 — Treaties expressed to be of perpetualduration

1. Subject to articles 18-22, and more particularly toarticles 18 and 19, a treaty shall continue in force per-petually, if —

(a) the treaty expressly states that it is to remain inforce indefinitely and does not provide for any right ofdenunciation or withdrawal; or

(b) the treaty expressly states that it is not to besubject to denunciation or withdrawal and does notprescribe any limit to its duration.

Commentary1. The following article deals with cases where thetreaty is totally silent both as to its duration and asto the right to denounce or withdraw from the treaty.The present article concerns the comparatively smallnumber of cases where the treaty appears expresslyon its face to contemplate that it shall remain in force" perpetually". This intention may be manifestedin two ways: either by expressly providing for thetreaty to remain in force indefinitely without providingfor any right to denounce or withdraw from it, or byexpressly excluding any right of denunciation or with-drawal without fixing any term to the treaty. Cases ofthese types are not very common, because a treatywhich is expressed to be of indefinite duration normallydoes provide for a right of denunciation or withdrawal,while a treaty which expressly excludes such a right isnormally one for a fixed term of years. Express declara-tions of the " perpetual " duration of a treaty are mostlikely to be found in those types of treaty which areinherently of a " permanent character " mentioned inarticle 17, paragraph 4, and especially those establishinga permanent international regime for a river or area. Arecent instance is the Indus Waters Treaty of I960,84

which provides that it is to remain in force until ter-minated by a further treaty between the two Govern-ments concerned. This treaty, since it merely makesits termination dependent upon the mutual agreement ofthe two interested States, is probably to be regarded asa true example of a " perpetual " treaty.

84 American Journal of International Law, 1961, pp.797-822.


Another recent treaty, the Antarctic Treaty S5 expresslyproclaims in its Preamble the intention of the Parties toset up a permanent regime for Antarctica. But article 12does provide for a right of withdrawal after thirty yearsin very special circumstances connected with the possibi-lity of a revision of the treaty. In consequence, theAntarctic Treaty seems to fall under paragraph 4 ofarticle 15 rather than under the present article.2. A treaty can in any event never be " perpetual "except in a qualified sense, since every treaty is liable tobe terminated by a subsequent treaty concluded betweenthe Parties; and in the case of a multilateral treaty theapplication of the treaty may even be terminated betweenindividual parties by a new agreement inter se. TheIndus Waters Treaty, as already mentioned, actuallyprovides that it shall " continue in force until terminatedby a duly ratified treaty concluded for that purpose be-tween the two Governments ". In order to avoid anymisunderstanding as to what is involved in a " perpe-tual " treaty the opening words of the present articleemphasize that it is subject to the provisions of arti-cles 18 and 19, which deal with the power to terminatetreaties by subsequent agreement.

Article 17 — Treaties containing no provisions regardingtheir duration or termination

1. Subject to Articles 18-22, the duration of a treatywhich contains no provisions regarding its duration ortermination shall be governed by the rules laid down inthis article.2. In the case of a treaty whose purposes are by theirnature limited in duration, the treaty shall not be sub-ject to denunciation or withdrawal by notice, but shallcontinue in force until devoid of purpose.3. (a) In cases not falling under paragraph 2, a partyshall have the right to denounce or withdraw from atreaty by giving twelve months' notice to that effect tothe depositary, or to the other party or parties, when thetreaty is —

(i) a commercial or trading treaty, other than oneestablishing an international regime for a particu-lar area, river or waterway;

(ii) a treaty of alliance or of military co-operation,other than special agreements concluded underarticle 43 of the Charter;

(iii) a treaty for technical co-operation in economic,social, cultural, scientific, communications or anyother such matters, unless the treaty is one fallingunder sub-paragraph (b);

(iv) a treaty of arbitration, conciliation or judicialsettlement.

(b) In the case of a treaty which is the constituentinstrument of an international organization, unless theusage of the organization otherwise prescribes, a partyshall have the right to withdraw from the treaty and fromthe organization by giving such notice as the competentorgan of the organization, in accordance with its appli-cable voting procedure, shall decide to be appropriate.

(c) When a treaty is terminable upon notice undersub-paragraph (a) or (b), its duration shall be determinedby article 15, paragraphs 3 and 4.

4. A treaty shall continue in force indefinitely withrespect to each party where the treaty —

(a) is one establishing a boundary between two States,or effecting a cession of territory or a grant of rights inor over territory;

(b) is one establishing a special international regimefor a particular area, territory, river, waterway, or air-space;

(c) is a treaty of peace, a treaty of disarmament, orfor the maintenance of peace;

(d) is one effecting a final settlement of an interna-tional dispute;

(e) is a general multilateral treaty providing for thecodification or progressive development of general inter-national law;provided always that the treaty does not lack essentialvalidity under any of the provisions of section II of thispart, and is not one entered into merely for the purposeof establishing a modus vivendi.5. In the case of any other treaty not covered by para-graphs 2-4, the duration of the treaty shall be governedby the rule in paragraph 4, unless it clearly appearsfrom the nature of the treaty or the circumstances of itsconclusion that it was intended to have only a temporaryapplication.6. Notwithstanding anything contained in the forego-ing paragraphs, a treaty which is silent as to its durationor termination but supplements or modifies anothertreaty shall be of the same duration as the treaty to whichit relates.

Commentary1. Article 17 covers the case of a treaty which neithercontains any provision regarding its duration nor regard-ing the right of the parties to denounce or withdrawfrom it. This type of treaty is not uncommon, recentexamples being the Charter of the United Nations, thefour Geneva Conventions on the Law of the Sea, 1958,and the Vienna Convention on Diplomatic Relations,1961. According to the traditional view, the general rulewas that stated in the Declaration of London of 1871:

" [Les Puissances] reconnaissent que e'est un prin-cipe essentiel du droit des gens qu'aucune Puissancene peut se delier des engagements d'un Traite, ni enmodifier les stipulations, qu'a la suite de 1'assentimentdes Parties Contractantes, au moyen d'une ententeamicale."

That famous Declaration, which concerned a unilateraldenunciation of certain clauses of the peace settlementafter the Crimean War, was as much a reassertion of theprinciple of the unanimity of the Great Powrers inEuropean treaty-making as of the principle pacta suntservanda.96 Moreover, the treaty which was the subjectof the Declaration was of a kind where the intention ofthe Parties normally is to create a stable settlement notsubject to denunciation. Nevertheless, the Declarationwas commonly represented as stating the general rulefor treaties which are not expressed to have any fixedduration and do not contain any power of denunciation.2. A large proportion of modern treaties, however,especially multilateral treaties, do contain provisionsfixing their duration or providing for a right of denuncia-

85 United Nations Treaty Series, vol. 402, p. 71.

SG E. C. Hoyt, The Unanimity Rule in the Revision ofTreaties: A Re-examination, p. 89.

Law of Treaties 65

tion or withdrawal; many indeed contain both kinds ofprovision. As multilateral treaty-making grew in thesecond half of the nineteenth century, the practicedeveloped of inserting denunciation clauses in treatiesdealing with technical matters.87 During the presentcentury the insertion of such clauses has become stan-dard practice in multilateral treaties dealing with parti-cular technical, economic, social or cultural matters, oneof the few exceptions being the treaty establishing theWorld Health Organization.88 The practice has alsospread into bilateral treaties, and it is now almost com-mon form for bilateral treaties dealing with these mattersto be made terminable by some form of notice when theyare not entered into for a fixed term. Indeed, the majorityof the modern treaties which are neither expressed tobe for a fixed term nor terminable upon notice areeither treaties which establish international regimes forparticular areas, rivers, etc., or treaties which havespecific objects of limited duration, and are therefore bytheir very nature finite.

3. Admittedly, the treaty clauses take very variedforms. Some make the treaty terminable immediatelyupon giving notice; others require six or twelve months'notice; some make the right of termination exercisablefrom the very outset of the treaty; others make it exercis-able only after the expiry of an initial fixed period; othersmake the treaty automatically renewable for fixedperiods and link the right of termination to the expiryof the successive periods; yet others connect the right oftermination with the revision of the treaty by majorityvote. But, despite the variety of the clauses, it is clearlypossible on the basis of the treaty practice to make outa case for the view that a treaty which does not fix itsown duration and whose life is not inherently finite byreason of the nature of its objects is regarded by Statesas one that should in most cases be terminable in somemanner and at some stage by unilateral denunciation orwithdrawal. The treaty practice, in fact, furnishes apossible basis for implying in certain classes of treatyan intention to allow a right of denunciation or with-drawal, even although the treaty itself is altogether silentupon the point. There is, however, some difference ofopinion as to exactly how far international law does orshould imply an intention to allow denunciation orwithdrawal in treaties which make no provision for it.Clearly, the question only arises v/here the treaty doesnot fix a specific period for its duration, because byfixing a period — even a long period — for the durationof the treaty, the parties have impliedly excluded anyright to denounce or withdraw from it in the meanwhile.But where no period has been fixed, the question of theright of denunciation or withdrawal is both importantand controversial.89

87 E. C. Hoyt , op. cit., pp . 18-19.88 Universality of membership was regarded as so impor-

tant in this organization that the normal denunciation clausewas omitted. It was, however, conceded in an interpretative" declaration " that if an amendment is made to the WHOConstitution by a majority vote, States in the minority havethe right to withdraw. The original ILO Constitution containedno right of withdrawal, but the amended constitution of1945 now provides for it.

89 See, for example, the United Nations Conference onthe Law of the Sea, Official Records, United Nations publica-tion, Sales No. 58.V.4, vol. II, document A/CONF. 13/38,pp. 19, 56 and 58.

4. The Harvard Research Draft insisted 90 that " atreaty may be denounced by a party only when suchdenunciation is provided for in the treaty or consented toby all other parties ". It recognized that there was reput-able authority for the view that a right of denunciationmay sometimes be implied in a treaty and that an in-creasing number of treaties, both bilateral and multila-teral, contained denunciation clauses. Nevertheless, itmaintained that the only safe solution was to lay downas the general rule for all treaties that " no State whichhas bound itself by a treaty may denounce it and with-draw without the consent of the other party or parties,given either in advance in the treaty itself or later in theform of a special agreement ". It considered that, unlesssuch consent were necessary, " the rule of pacta suntservanda would have little or no meaning ". Support forthe view that the principle enunciated in the Declarationof London is still the general rule of international law onthe question can certainly be found in State practice; forStates in protesting against what they conceived to beillegal denunciations of treaty obligations have notinfrequently couched their protests in much the samelanguage as the Declaration of London. On the basisof this practice Rousseau also took the position thatdenunciation of a treaty is only legitimate when effectedunder a power conferred by the treaty or with the consentof the other parties. The State practice in question,however, very largely relates to treaties intended to estab-lish permanent settlements, and as often as not to peacetreaties. The denouncing State was usually claiming torelease itself from the treaty in these cases on suchgrounds as rebus sic stantibus breaches by the otherparties, or the fact that the treaty had been imposed uponit. It was not claiming an implied right derived from thenature of the treaty and the general practice in regardto such treaties.5. A number of other authorities,91 while upholdingas the genera] rule the traditional doctrine that denuncia-tion is only permissible if the right has been expresslygranted in the treaty, recognize that the right may rea-sonably be implied in certain types of treaty. One well-known textbook,92 indeed, seems almost to hold thatthe general rule is that all treaties may be dissolved bywithdrawal after notice by one of the parties, " providedthat they are not such as are concluded for ever "; andthe same book maintains that " all such treaties as areeither not expressly concluded for ever, or are apparentlynot intended to set up an ever-lasting condition ofthings " may be dissolved after notice, even although theydo not expressly provide for the possibility of with-drawal. It also lists, as examples of such treaties, " com-mercial treaties " and " treaties of alliance not concludedfor fixed periods ", while excluding, on the other hand,from this class " treaties of peace " and " boundary trea-ties ". The most recent textbook on the law of treaties,'*13

on the other hand, maintains that " there is a generalpresumption against the existence of any right of unilate-ral termination of a treaty ", and appears only to admit" commercial treaties " as an exception to that presump-tion.

so Article 34, pp. 1173-1183.91 See Hall, International Law, 8th edition, p. 405; Oppen-

heim, International Law, 8th edition, Vol. 1, p. 938; McNair,Law of Treaties, pp. 501-5.

92 Oppenheim, loc. cit.93 McNair, op. cit., pp. 493 and 504.


6. The previous Special Rapporteur (A/CN.4/107,article 4, case A (ii)) considered that, in the absence ofany provision in the treaty, it is to be assumed that thetreaty is intended to be of indefinite duration and onlyterminable by mutual agreement of all the parties. Buthe also conceded that there are some exceptions whichhe formulated as follows.

" This assumption, however, may be negatived inany case (a) by necessary inference to be derived fromthe terms of the treaty generally, indicating its expiryin certain events, or an intention to permit unilateraltermination or withdrawal; (b) should the treatybelong to a class in respect of which, ex natura, afaculty of unilateral termination or withdrawal must bedeemed to exist for the parties if the contrary is notindicated . . . such as treaties of alliance, or trea-ties of a commercial character."

In his commentary he explained that his exception (a)covered cases where some general inference as to dura-tion may be drawn from the treaty as a whole by con-sidering the nature of the obligation; e.g., the partiesagree to take certain action " during the following year ",or so long as certain conditions continue, etc. As tothe exceptions under (b), he said: " It is generallythought that there are certain sorts of treaties which,unless entered into for a fixed and stated period orexpressed to be in perpetuity, are by their nature suchthat any of the parties to them must have an impliedright to bring them to an end or to withdraw from them ".Citing " treaties of alliance " and " commercial or tradingagreements " as instances of treaties where a right oftermination may be implied, he insisted that this excep-tion only extends to " treaties whose very nature imposessuch an implication as a necessary characteristic of thetype of obligation involved." He did not, in this con-nexion, make any distinction between bilateral andgeneral multilateral treaties, or make any special mentionof technical conventions.7. A recent study 94 of the revision and termination of" traites collectifs " examines the special case of generalmultilateral treaties which do not provide for their dura-tion or termination. The author of this study advancesthe view that, in the absence of a provision regardingdenunciation, any general multilateral treaty may bedenounced at any moment. " Cette opinion ", he ex-plains, " est fondee sur la consideration du caractere deces conventions qui sont legislatives par la nature deleur contenu et contractuelles par leur mode de forma-tion. Refuser aux parties le droit de denoncer les conven-tions generales pour lesquelles la convention elle-memen'a pas fixe un terme, ce serait reconnattre a la conven-tion un caractere de perpetuite a laquelle raisonnable-ment elle ne saurait pretendre." He then draws a dis-tinction between " perpetual treaties " and treaties ofunlimited or indefinite duration, and emphasizes that" un regime de droit n'est jamais perpetuel". Thisargument does not seem by itself to be convincing, sinceeven a so-called " permanent " treaty is terminable bysubsequent agreement, and the real point is whether theprocess for terminating obligations under a " legislative "treaty should be a unilateral act or a collective decision,whether unanimous or by majority.

8. On this point the same writer advances considera-tions of policy in favour of a general right to denouncemultilateral treaties which raise large issues:

" La participation aux conventions generales, estessentiellement volontaire. Nul Etat n'est oblige d'ydevenir partie. Logiquement, si les Etats ne sont pasobliges d'entrer, ils ne doivent pas etre empeches desortir.

" Pratiquement, il n'y a aucun avantage a faire desconventions generales qui sont fondamentalementvolontaires et libres des sortes de prison dans les-quelles une fois entre il ne serait plus possible desortir. Les Etats sachant qu'ils peuvent regulierementse degager au bout d'un temps relativement brefhesiteront beaucoup moins a s'engager. En fait, lesdenonciations ne sont pas tres frequentes, l'inertiejouant en faveur des situations existantes, mais lafaculte de denonciation qu'on pourrait utiliser, quoi-qu'on n'utilise generalement pas, apaise les inquie-tudes."

He went on to argue that a State which finds itselfthwarted by a general convention is unlikely to apply itloyally and that it is preferable that it should be able torelease itself from the convention. Violations of interna-tional law only weaken its authority, while if one Statedoes denounce a general convention, the convention nor-mally goes on being applied as if the State in question hadnever been a party. He concludes by suggesting that thebest way of achieving stability in treaty relations is toinclude a denunciation clause in every general multi-lateral treaty and always to imply one in cases where ithas been omitted; for a denunciation clause serves tosome extent to control States in denouncing treaties andto check them from doing so too precipitately.9. The insertion of denunciation clauses in generalmultilateral treaties was discussed at the Geneva Con-ference on the Law of the Sea in the context both ofcodifying conventions and of conventions making newlaw.95 As already mentioned, none of the four Conven-tions prepared by that conference contains a denuncia-tion clause. They only provide that after five years fromthe date of their entry into force any party may atany time request the revision of the Convention, andthat it will be for the General Assembly to decide uponthe steps, if any, to be taken in respect of the request.The Drafting Committee, in putting forward this revisionclause, observed that its inclusion " made unnecessaryany clause on denunciation ". Proposals had previouslybeen made for the inclusion of a denunciation clauseand these were renewed in the plenary meeting, notwith-standing the view of the Drafting Committee. Somerepresentatives thought it wholly inconsistent with thenature of a codifying convention to allow denunciation;some thought that a right of denunciation existed anyhowunder customary law; others considered it desirable toprovide expressly for denunciation in order to takeaccount of possible changes of circumstances. The pro-posal to include the clause in the " codifying " conven-tion was rejected by 32 votes to 12, with 23 abstentions.A similar proposal was also made with reference to theFishing and Conservation Convention which formulatedentirely new law. Here, opponents of the clause argued

84 E. Giraud, op. cit., pp. 66-77.

95 See United Nations Conference on the Law of the Sea,Official Records, vol. II, pp. 19, 56 and 58.

Law of Treaties 67

that a right of denunciation would be out of place in aConvention which created new law and was the result ofnegotiation. Advocates of the clause, on the other hand,regarded the very fact that the Convention created newlaw as justifying and indeed requiring the inclusion of aright of denunciation. Again, the proposal was rejected,the vote being 25 in favour and 6 against, with no fewerthan 35 abstentions. If the record of the discussions showssome uncertainty and difference of opinion as to thegeneral legal position in regard to the right to denouncegeneral multilateral treaties, the fact remains that thisConference considered and rejected a proposal to includea denunciation clause in these four Conventions.Moreover, the Vienna Conference of 1961 seems to haveomitted the clause from the Convention on DiplomaticRelations almost without discussion; and the ViennaConvention, it may be added, is one which does notcontain a revision clause.

10. Confronted with the conflicting opinions of juristsand with the large volume of State practice in whichcertain types of treaty are made terminable upon notice,the Special Rapporteur thinks it doubtful how far itcan be said today to be a general rule or presumptionthat a treaty which contains no provision on the matteris terminable only by mutual agreement of all the parties.In principle, the question is one of the intention of theparties in each case, for the parties are certainly free,as and when they wish, to make their treaty terminableupon notice. There is, however, some tendency toconfuse the question of the right of a party to denouncea treaty, under the treaty itself, with the question ofthe observance of the fundamental rule of pacta sunt ser-vanda. No doubt, the questions are not unconnected, butthe application of the pacta sunt servanda rule is depen-dent upon the terms of the " pactum " under considera-tion, and the question whether or not the parties intendedthe treaty to be terminable upon notice is one whichnecessarily arises prior to, and independently of, theapplication of the pacta sunt servanda rule. If the properconclusion is that, by reason of the nature and circum-stances of the treaty, the parties must be assumed tohave intended it to be subject to denunciation uponreasonable notice, a denunciation so effected is inconformity, not in contradiction, with the pacta suntservanda rule. There is also some tendency to confusethe right to denounce a treaty under the treaty itselfwith the right of a State to claim release from its treatyobligations by reason of a fundamental change in thecircumstances. Here again there is a connexion betweenthe two questions, because where there is a right ofdenunciation upon reasonable notice, the exercise ofthat right would be the natural way for a State toeffect its release from a treaty which it considers to havebecome outdated by changes in the circumstances. Butthere is a material difference between a right impliedin a treaty to terminate it at will upon reasonable noticewithout showing cause and a right to claim releasefrom it by establishing such a change in the circum-stances as brings the case under the provisions ofarticle 22. It is only the former right which is in issuein the present article.

11. If it be accepted that the question is essentiallyone of the intention of the parties, the problem stillremains as to the principles upon which that intentionis to be determined. Clearly, one possible view might

be that, whenever the parties do not make the treatyterminable on notice as they are free to do, they mustbe presumed not to have intended that it should be soterminable. In other words, failure to include a denuncia-tion clause would raise a presumption in every casethat the treaty is intended to be terminable only bymutual agreement. There would then be a general rule— derived not from the rule pacta sunt servanda, butfrom the apparent intention of the parties — that in theabsence of any provision making it terminable on notice,a treaty is only terminable by mutual agreement. Thatpresumption undoubtedly operates in certain classes ofcase. It may even, perhaps, be the ultimate generalrule.96 But, in the opinion of the Special Rapporteur,it is today, at most, a residuary rule; for there are verylarge and important classes of treaty where States sousually include a right of denunciation that the presump-tion must be the other way. The true position todayseems to be that there are certain classes of treaty whereby reason of the nature of the treaty the presumptionis against a right of denunciation and also certain classeswhere by reason of the nature of the treaty it is infavour of such a right. If any treaty falls outside theseclasses, it may be that the residuary rule applies. Butthe real difficulty is to define the different categoriesof treaty where the presumption in favour of a right ofdenunciation does or does not apply.

12. Paragraph 1, like paragraph 1 of article 15, is ofan introductory character, to define the cases with whichthe article is concerned.

13. Paragraph 2 covers treaties which are inherentlyfinite by reason of the nature of their purposes. Asalready mentioned in paragraph 2 of this Commentary,the majority of treaties concluded today which containno provision either for their duration or terminationare treaties whose purposes are of a transient characterand whose duration is therefore limited by their pur-poses. These treaties do not normally contain denuncia-tion clauses for the reason that they are intended tocontinue in force only until their purposes are discharged,when the treaty will die a natural death. Accordingly,in these cases the limited duration of the purposes, likea provision fixing a specific term to the treaty, raisesa presumption against the parties' having intended toallow denunciation upon notice. Obvious exampleswould be an agreement to arbitrate a particular disputeor to co-operate on a particular occasion or In theperformance of a particular task. The text of theparagraph states that the treaty will continue in forceuntil " devoid of purpose ", because it may come to anend through the failure as well as through the fulfilmentof its purposes.

14. Paragraph 3 (a) sets out four classes of case inwhich the nature of the treaty appears to raise a pre-sumption that it is to be regarded as essentially of alimited duration; and it proposes that these treatiesshould be considered to be terminable upon givingtwelve month's notice. No distinction has been madein these cases between bilateral, multilateral orgeneral multilateral treaties; for State practice does notappear to support the theory that all multilateral treatiesare to be regarded as terminable upon notice (see

96 Such clearly is the view of the previous Special Rap-porteur and of Lord McNair.


paragraph 8 above). If the great majority of multilateralconventions on technical matters contain an expressprovision rendering them terminable upon notice, thereason seems to be rather the nature of the matterswith which they deal than the fact that they are " traitescollectijs ". Precisely the same type of provision is veryoften to be found in bilateral treaties dealing with thesame matters, while the deliberate omission of a denun-ciation clause from the Geneva and Vienna Conventionsis scarcely consistent with the existence of a presump-tion that such a clause is to be read into every multi-lateral treaty. Moreover, some multilateral treatiesestablishing permanent international regimes (see para-graph 22 below) are clearly not inherently terminableupon notice.

15. Commercial or trading treaties are listed in sub-paragraph 3 (a) (i) as the first category of the caseswhich are impliedly terminable by notice when the treatyis silent upon the question. A number of authorities 97

support the view that these treaties are by their natureof limited duration and that, in consequence, they areto be regarded as terminable upon giving reasonablenotice, if the parties have failed to fix their durationin the treaty itself. On the other hand, a treaty whichis intended to establish an international regime of aneconomic kind for a particular area, river system, orwaterway is quite a different matter. There the intentionis normally to set up a continuing — " permanent" —regime, and the presumption is against the parties'having intended the regime to be terminable by unilateraldenunciation.98 These cases fall under paragraph 5.

16. Treaties of alliance or military co-operation, whichare covered in sub-paragraph 3 (a) (ii), are anothercategory where the treaty is commonly considered byits nature to be terminable " unless the contrary isexpressly provided. Although the point may appearsomewhat academic at the present moment, it seemsproper to exclude from this category " special agree-ments " concluded between Members of the UnitedNations and the Security Council under Article 43 ofthe Charter, should any such come into existence.

17. Sub-paragraph 3 (a) (iii) brings under the samerule treaties of technical co-operation, as being treatieswhich, under the existing practice, are habitually enteredinto for limited terms or made subject to denunciation.In most cases these treaties are entered into for recurringperiods of three, five or ten years, with a right todenounce at the end of each period, or they areentered into for a fixed period, with a provision thatthey shall continue in force thereafter unless twelve(or six) months' notice of denunciation is given. Again,in some cases they are entered into *' indefinitely"subject to denunciation at any time upon giving aspecified period of notice. The same is largely true ofthe constituent instruments of international organiza-tions which deal with matters of technical co-operation;but for the reason given in paragraph 20 it seemsadvisable to make a separate category of treaties which

are the constituent instruments of international organiza-tions.

18. In sub-paragraph 3 (a) (iv) the Special Rapporteurhas thought it right also to bring under this rule,however reluctantly, treaties of arbitration, conciliationor judicial settlement. It is only necessary to look atthe texts of the large number of such treaties collectedin the United Nations publication " Systematic Surveyof Treaties for the Pacific Settlement of InternationalDisputes, 1928-48 " 10° to see how almost invariablythey are concluded either for a fixed term or forrenewable terms subject to a right of denunciation, orare made terminable upon notice. One of the very fewexceptions out of over 200 treaties is the Treaty ofPeace, Friendship and Arbitration of 1929 betweenHaiti and the Dominican Republic, which contains noprovision regarding its duration or termination.101 If theproportion of instruments containing no provisionregarding their duration or termination is somewhatgreater among declarations under the " optional clause "of the Statute of the International Court of Justice (orof the Permanent Court), the general picture is the same.Out of the thirty-seven declarations listed in the Court'sYearbook for 1961-2, eight contain no statement as totheir duration or termination, and all the others aremade for a limited period or made terminable uponnotice. It is true that in 1938, when Paraguay, whichthen had a declaration of this kind, denounced it ina letter to the Secretary-General, six States 102 madereservations with regard to the denunciation; and thatthe Paraguayan declaration was retained in the list ofoptional clause acceptances in the Yearbook of theCourt until the year 1959-60, though with an expla-natory footnote mentioning the reservations. But thedeclaration has now been removed from the list, whileLiberia proceeded in 1952 to replace her previouslyunlimited declaration with a new declaration for a fixedterm, without meeting with any objection from anyState. Moreover, even before the Paraguayan denuncia-tion, Colombia had " corrected " in 1937 an unlimitedand unconditional declaration of 1932 by restricting itto disputes arising out of facts subsequent to 6 January1932. Taken as a whole, State practice under theoptional clause, and especially the modern trend towardsDeclarations terminable upon notice, seem only toreinforce the clear conclusion to be drawn from treatiesof arbitration, conciliation and judicial settlement, thatthese treaties are regarded as essentially of a terminablecharacter. Regrettable though this conclusion may be,it seems that "this type of treaty ought, in principle, tobe included in paragraph 3.

19. The period of notice suggested in sub-para-graph 3 (a) is twelve months. An alternative would beto say simply " reasonable " notice; but as the wholepurpose of paragraph 3 is to clarify the position wherethe parties have failed to deal with the duration of thetreaty, it seems better to propose a definite period ofnotice. A period of six months' notice is sometimesfound in termination clauses, but this in usually where

97 e.g. Hal l , op. cit., p . 405 ; Oppenheim, op. cit., vol. I ,p . 938; McNai r , op. cit.y p . 504; Sir G. Fi tzmaur ice , secondreport (A/CN.4/107), loc. cit.

98 See McNai r , op. cit., p . 505.99 See, for example , Oppenheim, loc. cit., and Sir G. Fi tz-

maur ice , loc. cit.

100 Uni ted Nat ions publicat ion, Sales N o . 1949.V.3; seepp. 331-1175; and for an analysis of the terminat ion clauses,see pp . 316-327.

101 Ibid., p . 530.10S All these States h a d themselves Declara t ions which

were for limited terms.

Law of Treaties 69

the treaty is of the renewable type and is open todenunciation by a notice given before or at the time ofrenewal. Where the treaty is to continue indefinitelysubject to a right of denunciation, the period of noticeis more usually twelve months, though in some casesthe denunciation takes effect at once. In formulating ageneral rule, it seems preferable to lay down a longerrather than a shorter period in order to protect theinterests of the other parties to the treaty and to give areasonable stability to the relations set up by the varyingkinds of treaty.

20. Constituent instruments of international organiza-tions are listed in sub-paragraph 3 (b) as a third categoryof treaties impliedly terminable upon notice. Nearly alltreaties of this kind deal expressly with the right todenounce the treaty or to withdraw from the organiza-tion, and in various ways seek to regulate the exerciseof the right. Amongst the exceptions are the well-knowncases of the United Nations and the World HealthOrganization; but these cases serve to confirm ratherthan to negative the existence of a general presumptionin favour of a right of withdrawal in this class of treaty.At San Francisco, although differing views wereexpressed during the discussion, the Conference ulti-mately agreed that a Member of the United Nationsmust be free in the last resort to withdraw from theOrganization. While omitting any denunciation orwithdrawal clause from the Charter for psychologicalreasons, the Conference adopted an " interpretativedeclaration " which included the following passage: 103

" The Committee adopts the view that the Chartershould not make express provision either to permit orto prohibit withdrawal from the Organization. TheCommittee deems that the highest duty of the nationswhich will become Members is to continue their co-operation within the Organization for the preservationof international peace and security. If, however, aMember because of exceptional circumstances feelsconstrained to withdraw, and leave the burden ofmaintaining international peace and security on theother Members, it is not the purpose of the Organiza-tion to compel that Member to continue its co-opera-tion in the Organization."

The draftsmen of the Constitution of WHO, by reasonof the world-wide character of the struggle againstdisease, placed great emphasis on the need for theorganization to be completely universal and, as in thecase of the Charter, deliberately omitted any withdrawalclause. However, when a majority procedure was intro-duced into the Constitution for adopting amendmentsto it, it was agreed that States which felt unable to acceptamendments so adopted ought to be free to withdraw.Accordingly, the WHO Conference also drew up aninterpretative declaration in the following terms: 104

" A member is not bound to remain in the Orga-nization if its rights and obligations as such werechanged by an amendment of the Constitution inwhich it has not concurred and which it finds itselfunable to accept."

One State 105 was allowed to make a reservation arrogat-ing to itself a general right of withdrawal outside theterms of the declaration; but when another State 106

withdrew from the organization for a period, it wastreated as a suspension rather than as a withdrawal ofmembership. The general understanding in the usageof WHO seems to be that withdrawal is not admissibleexcept under the conditions specified in the declaration.But the position is exceptional, and based upon theparticular need of universality in the work of the orga-nization. Sub-paragraph 3 (/>) seeks to cover such anexceptional position by excluding cases where there isa contrary usage in a particular organization. As tothe period of notice in these cases, the treaties whichcontain denunciation or withdrawal clauses not infre-quently specify twelve months. But it seemed better —in order to avoid any suggestion of amending theCharter or the constitution of any other organization —simply to specify such notice as the competent organ ofthe organization, in accordance with its applicable votingprocedure, shall decide to be reasonable. It is for thisreason that the constituent treaties of internationalorganizations have been separated from the treaties insub-paragraph 3 (c) (iii).

21. Sub-paragraph 3 (c) merely states that when atreaty is, by implication, terminable by notice undersub-paragraphs (a) and (b), its duration will be deter-mined on the same principles as those set out inarticle 15, paragraphs 3 and 4, for treaties which theparties have expressly made terminable by notice.22. Paragraph 4 lists five types of treaty in which theintention of the parties must be presumed to be toestablish a permanent treaty regime, in the sense of aregime which will continue indefinitely until revised orterminated by subsequent agreement. It is with regardto these types of treaty that most of the major contro-versies have arisen in the past concerning the unilateraldenunciation of treaties. In these controversies thedenouncing State has almost invariably invoked somealleged legal ground for setting aside the treaty — error,coercion, or fundamental change of circumstances; andby doing so has implicitly acknowledged the intrinsically" permanent " character of the treaty. Since it is inconnexion with these types of treaty that the questionof essential validity is most often raised, it has beenthought appropriate to reserve the question of essentialvalidity explicitly in a proviso to the present paragraph.The question of a fundamental change of circumstances— the doctrine of rebus sic stantibus — is alreadyreserved by the opening words of paragraph 1 of thisarticle. Mention is also made in the proviso of an excep-tion in the case of a modus vivendi, because it is quitepossible for a boundary or an " international regime "to be the subject of a modus vivendi; but the provisionalcharacter of the instrument will then normally beapparent from the terms of the treaty.

23. Paragraph 5 provides a residuary rule to catchtreaties that do not fall within paragraphs 2-4. Morefrom respect for the authorities than from any deepconviction, the Special Rapporteur has taken as the basicresiduary rule the presumption that in other cases a

103 U N C I O , Documents, vol. V I I , pp . 262-267; 327-329;Vol . V I , pp . 163-6; Vol . I, pp . 616-620.

"* W H O Official Records (1946), N o . 2, p . 74.

105 O. Schachter, " The Development of International Lawthrough the Legal Opinions of the United Nat ions Secreta-riat ", British Yarbook of International Law, 1948, p. 125.

106 W H O Official Records (1949), N o . 17, p . 52.


treaty is terminable only by subsequent agreement ofthe parties. Outside the *' permanent " types of treatydealt with in paragraph 4, modern treaty practice doesnot furnish much evidence of a general intention onthe part of States to enter into treaties which are tocontinue in force indefinitely unless terminated by agree-ment. On the contrary, in a rapidly changing world thetendency, as already mentioned, seems rather to be tofix a definite period for the duration of the treaty or,by various types of clause, to provide for its indefinitecontinuance subject to a right of denunciation underconditions fixed in the treaty.107 Accordingly, a casecan equally well be made out for formulating theresiduary rule in the reverse way. If the rule is statedin the traditional way, it seems essential to qualify itby excepting cases where a contrary intention appearsfrom the nature of the treaty, e.g. a modus vivendi, orfrom the circumstances of the conclusion of the treaty.24. Finally, paragraph 6 seeks to cover the quitecommon case of a protocol, exchange of notes or othersuch treaty which adds to or varies an existing treaty.These instruments usually make no mention of theirown duration, and the intention clearly is that theyshould simply be regarded as an annex to the originaltreaty.

Article 18—Termination of a treaty by subsequentagreement

1. Notwithstanding articles 15-17, a treaty may beterminated at any time —

(a) in the case of a treaty drawn up at an interna-tional conference convened by the States concerned orby an international organization, by the agreement ofnot less than two-thirds of the States which drew upthe treaty, including all those which have become partiesto the treaty, provided that, if X years have elapsedsince the date of the adoption of the treaty, only theagreement of the States parties to the treaty shall benecessary;

(b) in the case of a treaty drawn up within aninternational organization, by a decision of the compe-tent organ of the organization in question, adopted inaccordance with the applicable voting rule of suchorgan;

(c) in other cases, by the mutual agreement of theparties.2. However, where a treaty prescribes a specific pro-cedure for its amendment or revision, such procedureshall, so far as is appropriate, also be applied for thepurpose of effecting its termination.3. An agreement terminating a treaty under sub-para-graphs (a) or (c) of paragraph 1 may be embodied —

(a) in a new treaty drawn up in whatever form theparties may decide;

(b) in communications made by the parties to thedepositary of the treaty or to each other;

(c) in a tacit agreement, where one party has pro-posed the termination of the treaty or purported todenounce it, and it clearly appears from the circum-stances that the other party or parties assented to suchtermination or denunciation of the treaty.

107 Consular Conventions, for example, are frequentlymade terminable upon notice.

4. (a) If a depositary receives from a party to thetreaty either a proposal for its termination or a requestto withdraw from it, the depositary —(i) in a case falling under sub-paragraphs 1 (a) and

1 (c), shall communicate such proposal to the Stateswhose agreement is specified in those sub-paragraphsas being material;

(ii) in a case falling under sub-paragraph 1 (b), shallbring such proposal or request, as soon as possible,before the competent organ of the organization inquestion.

(b) The agreement of a State to which a proposal orrequest has been communicated under sub-para-graph 3 (a) (i) shall be presumed after the expiry oftwelve months from the date of the communication, ifit has not notified the Depositary of its objection to theproposal or request.

5. The provisions of the foregoing paragraphs regard-ing the termination of treaties by subsequent agreementshall also apply, mutatis mutandis, to their suspensionby subsequent agreement.

Commentary

1. Where the treaty itself provides for an expressright of denunciation, or where such a right is to beimplied under article 17, the termination of the treatyis unlikely to give rise to any problem. Where, however,there is no such right, serious difficulties may arise. Inthe past, the termination of treaty obligations has toooften taken the form of a unilateral and disputed asser-tion of a right to denounce the treaty. Particular impor-tance attaches therefore to providing orderly proce-dures by which, when there are good reasons for doingso, States may seek to secure the termination or suspen-sion of their treaty obligations by some form of agree-ment. Even when a party conceives itself to have a rightto terminate the treaty on some specific ground, it isextremely desirable that it should seek if possible tobring about the termination of the treaty by consentrather than by a unilateral assertion of its supposedright.

2. The process of terminating has some analogy withthat of creating a treaty regime. But the legal situationis more complex in that the parties to a treaty havevested rights in the treaty itself of which they will bedeprived by its termination; and it is a stronglyentrenched principle of international law that a treatycannot by itself deprive third States of their rights undera prior treaty. Admittedly, it is possible to questionwhether the application of this principle to generalmultilateral treaties is entirely desirable, since it mayimpede the replacement of an out-of-date treaty by anew treaty. But there is always the danger that, fromsheer inertia, some parties to an older treaty may failto become parties to a more recent one; and the principleprecluding even general multilateral treaties fromaffecting the position of non-parties under earlier treatiesserves to keep alive some treaty obligations which mightotherwise lapse. Accordingly, although the result maybe to complicate treaty relationships and to impede thereplacement of out-of-date treaties, it is necessary to becautious in proposing, even de lege ferenda, rules per-mitting the termination of treaties by any form ofmajority decision, such as the Commission has proposedin article 6 of part I for the adoption of a treaty text.

Law of Treaties 71

Paragraph 1 therefore sets out the main rules for thetermination of treaties in three sub-paragraphs, on thesame pattern as the rules proposed by the Commissionin article 6 of part I for the adoption of the text, butmaking the consent of all the parties to the treaty thegeneral rule except in the case of a treaty actuallydrawn up within an international organization.3. Sub-paragraph 1 (a) covers multilateral treatiesdrawn up at international conferences convened eitherby the States themselves or by an international organiza-tion. For the reason already given, it seems necessaryto lay down that the termination of a multilateral treaty,in principle, requires the consent of all the States partiesto the treaty. But in the case of multilateral treaties,and especially general multilateral treaties, it also seemsnecessary to take account of the interests of States whichparticipated in the adoption of the text but have notyet become parties to the treaty owing to a delay insigning, ratifying, accepting, approving or acceding tothe treaty. These States, by the terms of the treaty itself,are entitled to become parties to the treaty by performingthe required act; and for at least some reasonable periodof time it ought not to be open to the States which havealready become parties — perhaps only two or a veryfew States — to deprive them of this right.108 Accord-ingly, without attempting to fix the exact period, sub-paragraph 1 (a) provides that for a period of X yearsthe termination of the treaty requires the consent oftwo-thirds of all the States which drew up the treaty,including all those which are actual parties. In for-mulating analogous provisions in part I, the Commis-sion preferred to leave the length of the period undefined,until the views of Governments have been obtained. Aperiod of the order of ten years is what the SpecialRapporteur envisages.4. Sub-paragraph 1 (b) covers the case of treaties,like the Genocide Convention and the Convention on thePolitical Rights of Women, which are drawn up actuallywithin an international organization. Admittedly, treatiesof this type, when drawn up, are opened to signature,ratification, acceptance, etc., and States become partiesto them in the normal way. It is therefore arguable thatthey should be dealt with in the same way as treatiesdrawn up at a conference. Nevertheless, when a treatyhas been drafted within an organization and then adoptedby a resolution of one of its organs, there is a case forsaying that the organization has an interest in the treatyand that its termination should be a matter for theorganization. Accordingly, although it may involve somederogation from the normal principle that a State cannotbe deprived of its rights under a treaty without itsconsent, it seems justifiable to propose that the termina-tion of the treaty should be a matter for the organiza-tion. The genesis of the treaty in a decision of theorganization is known to States when they becomeparties, and it seems reasonable to assume that theyrecognize the association of the organization with thetreaty.

5. Sub-paragraph 1 (c) states the general rule forbilateral treaties and for other treaties not falling undersub-paragraphs 1 (a) and (b); the termination of thetreaty requires the unanimous consent of the parties.

6. Paragraph 2 proposes, de lege ferenda, that wherea treaty lays down a specific procedure for the amend-ment or revision of a treaty, the same procedure shall,so far as is appropriate, be applied for effecting itstermination. It seems only logical that, where the partieshave selected a particular means of bringing about thealteration of the treaty, they should be assumed to intendthe same means to be employed for the even morefundamental step of terminating it.7. Paragraph 3 provides that a subsequent agreementto terminate a treaty may take the form either of anew treaty or of notifications to the depositary of thetreaty which is to be terminated. It is sometimes saidthat the subsequent agreement must be cast in thesame form as the treaty which is to be terminaied, orat least be a treaty form of " equal weight ". This viewhas, for example, been expressed by the United States,103

but it reflects the constitutional practice of individualStates, not a general rule of treaty law. It is always forthe States concerned themselves to select the appropriateinstrument or procedure for bringing a treaty to an endand, in doing so, they will no doubt have in mind theirown constitutional requirements. Paragraph 3 furtherrecords that the termination of a treaty may also comeabout through a tacit agreement. Whether in any givencase the process is that of " estoppel " or " subsequentagreement " may not always be clear. But the generalview seems to be that tacit agreement may be enoughto terminate a treaty.110

8. Paragraph 4 (a) is essentially procedural, indicat-ing the action to be taken by a depositary on receivinga notification from a party proposing the terminationof the treaty. Then, in order that the procedure forterminating treaties by consent through the machineryof a depositary should not be frustrated through themere inertia of individual States in responding to aproposal, paragraph 4 (b) proposes that the assent ofa State should be presumed after the expiry of twelvemonths (a similar presumption was adopted by theCommission in article 19 of part I in connexion withthe acceptance of reservations).9. Where the reasons which cause the parties to wantto release themselves from the obligations of a treatyare of a temporary character, it may happen that theyprefer to suspend rather than terminate the treaty. Inthat event the same principles would seem to be ap-plicable, and paragraph 5 so provides.

Article 19 — Implied termination by entering intoa subsequent treaty

1. Where all the parties to a treaty, either with orwithout third States, enter into a new treaty relating tothe same subject-matter, without expressly abrogatingthe earlier treaty, the earlier treaty shall nevertheless beconsidered to be impliedly terminated —

(a) when the parties to the later treaty have mani-fested an intention that the whole matter shouldthereafter be governed by the later treaty; or

(b) when the provisions of the later treaty are so far

178 Quite a number of multilateral conventions come intoforce upon only two or a very small number of signatures,ratifications, etc.

109 See an observation of the United States delegate atthe 49th meeting of the Social Committee of the Economicand Social Council (E/AC.7/SR.49, p. 8), to which Sir G.Fitzmaurice drew attention.

»° See Sir G. Fitzmaurice's second report (A/CN.4/107),articles 12 and 14.


incompatible with those of the earlier one that the twotreaties are not capable of being applied at the sametime;unless in either case it appears from the circumstancesthat the later treaty was intended only to suspend the op-eration of the earlier treaty for a limited period of time.2. (a) If two parties or a number of the parties to atreaty, either with or without third States, enter into anew treaty relating to the same subject-matter, withoutexpressly abrogating the earlier treaty, the applicationof the earlier treaty shall nevertheless be considered tobe impliedly terminated as between the States which areparties to both treaties in the same circumstances asthose set out in paragraph 1.

(b) However, the fact that the application of theearlier treaty is so terminated as between those of itsparties which are also parties to the later treaty shallnot affect its application either as between the Stateswhich are parties only to the earlier treaty or as betweenany such State and a State which is a party to bothtreaties.3. When the termination of a treaty takes place byimplication under the preceding paragraphs, the date ofits termination shall be the date upon which the latertreaty comes into force, unless the later treaty shallotherwise provide.Commentary1. This article covers, from the different standpointof the termination of treaties, the cases of conflictbetween treaties which are the subject of article 14. Itwas pointed out in the Commentary to that article that,where there are two successive treaties on the samesubject, the parties to which are identical, the Statesconcerned, when they conclude the second treaty, arefully competent to amend or annul the prior treaty; andthat the effect of the second treaty upon the prior treatyis essentially a question of what the contracting Statesintend when they conclude the second treaty. They mayintend simply to supplement the earlier treaty or torevise it, or they may intend that the second treaty shouldreplace it completely.

2. Paragraph 1 of the present article seeks to definethe conditions under which the parties to a treaty areto be understood as having intended to terminate itby concluding a later treaty the parties to which areidentical. The wording of the two clauses in paragraph 1is based upon the treatment of the matter in the separateopinion of Judge Anzilotti in the Electricity Companyof Sofia case,111 where he said:

" There was no express abrogation. But it isgenerally agreed that, beside express abrogation, thereis also tacit abrogation resulting from the fact that thenew provisions are incompatible with the previousprovisions, or that the whole matter which formedthe subject of these latter is henceforward governedby the new provisions."

The Court in that case differed from Judge Anzilottiin thinking that there was no incompatibility betweenthe two instruments by which the parties had acceptedcompulsory jurisdiction. Nevertheless, the passage citedfrom Judge Anzilotti's opinion provides what is thoughtto be a useful formulation of the criteria for determining

P.C.I.J. Series A/B, No. 77, p. 92.

whether or not a second instrument abrogates a priorinstrument dealing with the same subject-matter.3. In the same opinion Judge Anzilotti held that theBelgian and Bulgarian declarations under the optionalclause, although in his view incompatible with anearlier Belgo-Bulgarian Treaty of Conciliation, had notabrogated it because the Treaty was of indefinite dura-tion, whereas the declarations were for limited terms ofyears. Without in any way questioning the correctnessof that finding in the particular context of the treatyand the two declarations in that case, it may be doubtedwhether it can be said to be a general principle that alater treaty for a fixed term can never abrogate anearlier treaty expressed to have a longer or indefiniteduration. It depends entirely upon the intention of theStates in concluding the second treaty. If their intentionapparently was that the whole matter should afterwardsbe governed by the new treaty, it seems unwarranted toassume that they intended the earlier treaty to revive,on the expiry of the new treaty. It seems more likelythat what they had in mind was a need to review thesituation after the end of the second treaty. Paragraph 1merely provides, therefore, that abrogation shall notoccur if it is clear from the circumstances that the latertreaty was intended to replace the earlier one onlytemporarily.4. Paragraph 2 deals with the same general problem,but in cases where the parties to the second treaty donot include all the parties to the first treaty. Here theprinciple that a treaty cannot by itself deprive non-parties of their rights, whether under general interna-tional law or under a prior treaty, comes into play;and, as pointed out in the Commentary to article 14,some authorities for that reason call in question thevery validity of the second treaty. The rule proposed inarticle 14 accepts the validity of the second treaty,despite its conflict with the prior treaty; and on thatbasis the second treaty is effective in the relationsbetween the States which are parties to it. Accordinglythe problem arises as to whether in this type of casealso the second treaty terminates the earlier one. Asbetween the States which are parties to both treaties,the question is again essentially one of their intentionwhen concluding the second treaty, and the rules laiddown in paragraph 1 would seem to be equally appli-cable. Sub-paragraph (a) so provides. But these rulesare only relevant for determining the position of theStates which are parties to both treaties, because theyare only competent to terminate the application of theearlier treaty as between themselves, and cannot disposeof the rights of the other parties to the earlier treaty.Accordingly, sub-paragraph (b) preserves the earliertreaty in being (1) as between the States which areparties only to the earlier treaty and (2) as between anyof those States and a State party to both treaties.5. Paragraph 3 simply provides that the date on whichthe implied termination of the earlier treaty takes placeis the date on which the second treaty comes into force,unless the second treaty otherwise provides.

Article 20 — Termination or suspension of a treatyfollowing upon its breach

1. (a) The breach of a treaty by one party does notof itself have the effect of terminating the treaty or ofsuspending its operation.

Law of Treaties 73

(b) Under the conditions set out in the followingparagraphs of this article, however, a material breachof a treaty by one party entitles the other party orparties to denounce or withdraw from the treaty or tosuspend, in whole or in part, its operation.

2. A material breach of a treaty results from —(a) a repudiation of the treaty by a representative

or organ of the State competent to express the willof the State to denounce the treaty;

(b) a breach so substantial as to be tantamount tosetting aside any provision —(i) with regard to which the making of reservations is

expressly prohibited or impliedly excluded underarticle 18, paragraph 1 (a), (b) and (c) of part I; or

(ii) the failure to perform which is not compatible withthe effective fulfilment of the object and purpose ofthe treaty;

(c) a refusal to implement a provision of the treatybinding upon all the parties and requiring the submis-sion of any dispute arising out of the interpretation orapplication of the treaty to arbitration or judicial settle-ment, or a refusal to accept an award or judgementrendered under such a provision.3. In the case of a bilateral treaty, a material breachby one party constitutes a ground upon which the otherparty may either —

(a) denounce the treaty or suspend its operation,subject to the reservation of its rights with respect to anyloss or damage resulting from the breach; or

(b) denounce only the provision of the treaty whichhas been broken or suspend its operation, subject to thesame reservation.4. In the case of a multilateral treaty other than onefalling under paragraph 5, a material breach by oneparty constitutes a ground upon which —

(a) any other party may, in the relations betweenitself and the defaulting State, either —(i) terminate or suspend the application of the treaty,

subject to the reservation of its rights mentioned inparagraph 3; or

(ii) terminate or suspend the application only of theprovision of the treaty v/hich has been broken,subject to the same reservation;

(b) the other parties to the treaty, by an agreementarrived at in accordance with the provisions of article 18of this part, may collectively either —(i) terminate the treaty or suspend its application; or

(ii) terminate or suspend the application only of theparticular provision which has been broken.

Provided that, if a material breach of a treaty by oneor more parties is of such a kind as to frustrate theobject and purpose of the treaty also in the relationsbetween the other parties not involved in the breach,any such other party may, if it thinks fit, withdrawfrom the treaty.5. In the case of a material breach of a treaty which isthe constituent instrument of an international organiza-tion, or which has been concluded within an interna-tional organization, any question of the termination orsuspension of the rights or obligations of any party to thetreaty shall be determined by decision of the competentorgan of the organization concerned, in accordance withits applicable voting rules.

Commentary1. The great majority of writers n 2 recognize that theviolation of a treaty by one party may give rise to aright in the other party to abrogate the treaty or tosuspend the performance of its own obligations underthe treaty. Nor is it easy to see how the rule could beotherwise, since good sense and equity rebel at the ideaof a State being held to the performance of its obliga-tions under a treaty which the other contracting partyis refusing to respect. Moreover, on general principles,a violation of a treaty right, as of any other right, maygive rise to a right to take non-forcible reprisals and,clearly, these reprisals may properly relate to thedefaulting party's rights under the treaty. Opiniondiffers, however, as to the extent of this right and theconditions under which it may be exercised. Somewriters,113 in the absence of effective internationalmachinery for securing the observance of treaties, aremore impressed with the innocent party's need to havethis right as a sanction for the violation of the treaty.These writers tend to formulate the right in unqualifiedterms, giving the innocent party a general right to abro-gate the treaty in the event of a breach.11'1 Other writersare more impressed with the risk that a State may allegea trivial or even fictitious breach simply to furnish apretext for denouncing a treaty which it now findsembarrassing.115 These writers tend to restrict the rightof denunciation to " material " or " fundamental "breaches and also to subject the exercise of the rightto procedural conditions.11"

2. State practice, although not lacking,117 does not givemuch assistance in determining the true extent of thisright or the proper conditions for its exercise. In mostcases, the denouncing State has been determined, forquite other reasons, to put an end to the treaty and,having alleged the violation primarily to provide arespectable pretext for its action, has not been preparedto enter into a serious discussion of the legal principlesgoverning the denunciation of treaties on the basis ofviolations by the other party. Moreover, the other partyhas usually contested the denunciation primarily on thebasis of the facts; and, if it has sometimes used languageappearing to deny that unilateral denunciation is ever

112 See Harvard Law School, Research in InternationalLaw, III, Law of treaties, pp. 1081-3; McNair, op. cit., p. 553.C. Rousseau seems to have doubted whether customary lawrecognizes a right to denounce a treaty on the ground ofthe other party's non-performance, because claims to do sohave usually been objected to. But for the reasons given inparagraph 2 this can hardly be regarded as sufficient evidenceof the non-existence of any such customary rights.

113 e.g. Hall, op. cit., p. 408; S. B. Crandall, Treaties, theirMaking and Enforcement, p. 456; Ch. Dupuis, " Liberte desvoies de communication, Relations internationales ", Recueildes cours de V Academie de droit international, 1924-1), vol. 2,p. 340; A. Cavaglieri, " Regies generates du droit de lapaix ", Recueil des cours de I'Academie de droit international(1929-1), vol. 26, p. 535.

111 See Oppenheim, op cit., p. 947.115 e.g., McNair, op cit.. p. 571; C. C. Hyde, Interna-

tional Law, vol. 2, p. 1543; E. Giraud, op. cit., p. 28.11(! See Harvard Low School, Research in International

Law. Ill, Law of treaties (articl 27), p. 1077 and pp. 1091-1092.

117 Hackworth, Digest of International Law, vol. 5, pp.342-348; Harvard Law School, Research in International Law,III, Law of treaties, pp. 1083-1090: McNair, op. cit., pp. 553-569; A. C. Kiss, Repertoire francais de droit international,Vol. 5, pp. 102-121; Fontes Juris Gentium, Series B, Sec-tion 1, tomus I, part I (2), pp. 791-792.


justified by any breach, this has usually appeared ratherto be a protest against the one-sided and arbitrarypronouncements of the denouncing State than a rejec-tion of the right to denounce when serious violationsare established. Thus, States which have on one occa-sion seemed to assert that denunciation is always illegiti-mate in the absence of agreement have on others them-selves claimed the right to denounce a treaty on thebasis of breaches alleged to have been committed bythe other party.

3. Municipal courts have not infrequently made pro-nouncements recognizing the principle that the violationof a treaty may entitle the innocent party to denounceit. But they have nearly always done so in cases wheretheir Government had not in point of fact elected todenounce the treaty and they have not found it necessaryto examine the conditions for the application of the prin-ciple at all closely.118

4. International jurisprudence has contributed compa-ratively little on this subject. In the case of the Diversionof Water from the River Meuse,119 the question of theeffect of a violation of a treaty upon the obligation ofthe other party to perform the treaty was raised, but ina somewhat different way. Belgium there contendedthat, by constructing certain works contrary to the termsof the Treaty of 1863, Holland had forfeited the rightto invoke the treaty against Belgium. While it did notclaim to denounce the treaty, Belgium did in effectassert a right, as a defence to Holland's claim, to suspendthe operation of one of the provisions of the treaty onthe basi of Holland's alleged breach of that provision,although pleading the claim rather as an application ofthe principle inadimplenti non est adimplendum. TheCourt, having found that Holland had not violated thetreaty, did not pronounce upon the Belgian contention.In a dissenting opinion, however, Judge Anzilottiexpressed the view 120 that the principle underlying theBelgian contention is " so just, so equitable, so univer-sally recognized that it must be applied in internationalrelations also ". That case did not therefore carry thequestion very far, and the only other case that seemsto be of any significance is the Tacna-Arica Arbitra-tion.1'21 Here Peru contended that by preventing theperformance of article 3 of the Treaty of Ancon, whichprovided for the holding of a plebiscite under certainconditions in the disputed area, Chile had dischargedPeru from its obligations under that article. The Arbi-trator,122 after examining the evidence, rejected thePeruvian contention, saying:

" It is manifest that if abuses of administrationcould have the effect of terminating such an agreement,it would be necessary to establish such serious condi-tions as the consequence of administrative wrongs aswould operate to frustrate the purpose of the agree-ment, and, in the opinion of the Arbitrator, a situationof such gravity has not been shown."

118 e.g. Ware v. Hylton (1796), 3 Dallas 261; Charlton v.Kelly, 229 U.S. 447; Lepeschkin v. Gosweiler et Cie., Jour-nal du droit international (1924) vol. 51 , p. 1136; In reTatarko, Annual Digest and Reports of Public InternationalLaw Cases, 1949, No . 110, p. 314.

119 P.C.I.J., Series A / B , N o . 70.12« Ibid., p. 50; cf. Judge Hudson, pp. 76-77.121 Reports of International Arbitral Awards, Vol. II , pp.

929 and 943-4.122 President Coolidge of the United States.

This pronouncement certainly seems to assume that onlya " fundamental " breach of article 3 could have justifiedPeru in claiming to be released from its provisions.

5. The previous Special Rapporteur (A/CN.4/107,articles 18-20 and commentary) leaned strongly to theside of those who are more impressed with the riskthat this ground of denunciation may be abused thanwith its value as a sanction for securing the observanceof treaties. His proposals therefore showed a markedconcern to circumscribe and regulate the right todenounce a treaty on the ground of a breach by theother party. This concern manifested itself in a numberof ways in his proposed rules.

6. In the first place, his draft limited the right ofdenunciation to cases of " fundamental breach ", whichhe defined as " a breach of the treaty in an essentialrespect, going to the root or foundation of the treatyrelationship between the parties, and calling in questionthe continued value or possibility of that relationshipin the particular field covered by the treaty ". The draftfurther provided (article 19, paragraph 2 (i) and (ii))that the breach " must be tantamount to a denial orrepudiation of the treaty obligation, and such as eitherto (a) destroy the value of the treaty for the other party;(b) justify the conclusion that no further confidencecan be placed in the due execution of the treaty by theparty committing the breach; or (c) render abortivethe purposes of the treaty". By another provision(article 18, paragraph 2) the draft distinguished cases offundamental breach from " cases where a breach by oneparty of some obligation of a treaty may justify anexactly corresponding non-observance by the other, or,as a retaliatory measure, non-performance of some otherprovision of the treaty ". He considered that " in suchcases there is no question of the treaty, or of its obliga-tions, as such, being at an end; but merely of particularbreaches and counter-breaches, or non-observances, thatmay or may not be justified according to circumstances,but do not affect the continued existence of the treatyitself ".

7. Secondly, the previous Special Rapporteur consi-dered " fundamental breach " as a ground for termina-tion to apply in principle only in the case of bilateral,not multilateral, treaties (article 19, paragraph 1 (i) ofhis draft) and he recognized a right to terminate a multi-lateral treaty only in one instance (ibid, article 19, para-graph 1 (ii)). He separated multilateral treaties into twobroad categories. One covered treaties where the obliga-tions are of a " reciprocal ", or " interdependent ", type,and with regard to these treaties his draft stated (ibid.)that a fundamental breach will justify the otherparties —

(a) in their relations with the defaulting party, inrefusing performance for the benefit of that party ofany obligations of the treaty which consist in a reciprocalgrant or interchange of rights, benefits, etc.;

(b) in ceasing to perform any obligations of the treatywhich have been the subject of the breach and whichare of such a kind that their performance by any partyis necessarily dependent on an equal or correspondingperformance by all the other parties.

His draft further stated (article 19, paragraph 1 (Hi)) thatin the case of this type of treaty, "if [one] partycommits a general breach of the entire treaty in such a

Law of Treaties 75

way as to constitute a repudiation of it, or a breachin so essential a particular as to be tantamount to arepudiation, the other parties may treat it as being atan end or any one of them may withdraw ". With regardto the second category of treaties, on the other hand,he did not consider that a breach can ever justify eithertermination of or withdrawal from the treaty, or evennon-performance by the other party of its obligationsin respect of the defaulting State. The treaties whichhe placed in this category were (a) law-making treaties,(b) treaties either creating international regimes for aparticular area, region, etc., or involving undertakingsto conform to certain standards and conditions, and (c)' any other treaty where the juridical force of the obliga-tion is inherent, and not dependent on a correspondingperformance by the other parties to the treaty . . . sothat the obligation is of a self-existent character,requiring an absolute and integral application andperformance under all conditions ".

8. Thirdly, the previous Special Rapporteur's draft(article 19, paragraph 3) negatived the right to terminatea treaty on the basis of a fundamental breach if —

(a) the treaty is due to expire in any event within areasonable period;

b) the claim to terminate is not made within a reason-able time of the breach;

(c) the other party has condoned or waived thebreach; or

(d) the party claiming to terminate itself caused orcontributed to the breach.The last three paragraphs are of course expressions ofwell-recognized general principles, (c) being covered inarticle 4 of the present draft articles.

9. Finally, the previous Special Rapporteur (in article20 of his draft) laid down certain procedural conditions,the observance of which would be a sine qua non forthe legitimate exercise of a right to terminate a treaty onthe ground of its alleged breach by the other party.These conditions would require a State claiming toterminate a treaty on the ground of another party'sbreach (a) to present a reasoned statement of its caseto the other party in question; (b) to give a reasonabletime for the other to reply; (c) if the other party con-tested the case, to offer to refer the matter to an inde-pendent tribunal for decision; and (d) not to denouncethe treaty unless the other party either failed to makeany reply to the statement of the case or declined theoffer to refer the matter to a tribunal. The question ofthe procedural requirements for denouncing a treatyalso arises in other connexions, not only in regard toother grounds of termination but also in regard to casesunder section II of the present draft. Accordingly, inthe present draft they will be found dealt with in ageneral article in section IV.

10. The present Special Rapporteur, while having thesame general approach to this question as his predeces-sor, believes that in some points his predecessor's draftmay go a little further in limiting the right to terminateor suspend treaty relations with a covenant-breakingState than is altogether acceptable. These points willemerge and be discussed later in the present Commen-tary. Fortunately, the area in which the role of this articleis likely to be important is somewhat narrowed by themodern practice of giving to many classes of treaties

comparatively short periods of duration or of makingthem terminable by notice. In these cases the injuredparty will usually have a simple and uncontroversialmeans of bringing the treaty to an end. It is primarilywhen treaties have been entered into either for longerfixed terms or indefinitely that the article may have asignificant part to play.

11. Paragraph 1 (a) states what appears to be theuniversally accepted principle that the violation of atreaty, however serious, does not of itself put an end tothe treaty.123 This principle has frequently been insistedupon by judges in municipal courts, when private par-ties have claimed that a treaty ought to be disregardedby reason of its violation by the other High Contract-ing Party.124 Paragraph 1 (b) merely states that underthe conditions laid down in the article a " material "breach may give rise to a right in the other party orparties to the treaty to terminate or withdraw from thetreaty or suspend its operation. The present SpecialRapporteur believes that the word " material " used bysome authorities is to be preferred to the word " fun-damental " to express the kind of breach which mayentitle the other party to terminate the relationshipestablished by the treaty. The word " fundamental "might be understood as meaning that only the violationof a provision directly touching the central purposes ofthe treaty can ever justify the other party in terminatingthe treaty. But other provisions considered by a partyto be essential to the effective execution of the treatymay have been very material in inducing it to enter intothe treaty at all, even although these provisions may beof an entirely ancillary character. For example, a clauseproviding for compulsory arbitration in the event of adispute as to the interpretation or application of thetreaty is purely ancillary to the main purposes of thetreaty, but it may well be regarded by some partiesas an essential condition for agreeing to be bound by thetreaty. In that case a refusal to arbitrate would go tothe root of the other party's consent to be in treaty rela-tions with the defaulting State.12. Paragraph 2 seeks to define, so far as it is possibleto do so, what may constitute a " material breach "giving rise to a right to terminate or suspend the treaty.The difficulties of this task were admirably stated by anineteenth-century writer: 125

" Some authorities hold that the stipulations of atreaty are inseparable, and consequently that theystand and fall together; others distinguish betweenprincipal and secondary Articles, regarding infractionsof the principal Articles only as destructive of thebinding force of a treaty. Both views are open toobjection. It may be urged against the former thatthere are many treaties of which slight infractions maytake place without any essential part being touched,that some of their stipulations, which were originallyimportant, may cease to be so owing to an alterationin circumstances, and that to allow states to repudiatethe entirety of a contract upon the ground of such

123 H a r v a r d L a w School , Research in International Law,HI, Law of Treaties p . 1078; Fauchi l le , Traite de droit inter-national public, 8th edition, vol . 1, par . I l l , pa ra . 854; J. Spi-ropoulos , Traite de droit international public, p . 257.

124 e.g. Ware v. Hylton (1796) 3 Dal las 2 6 1 ; Charlton v.Kelly (1913) 229 U.S . 447; In re Tatarko, Annual Digest ofInternational Law Cases 1949, N o . 110.

12 s W. E . Hal l , op. cit., pp . 408-9.


infringements is to give an advantage to those whichmay be inclined to play fast and loose with theirserious engagements. On the other hand, it is truethat every promise made by one party in a treaty maygo to make up the consideration in return for whichessential parts of the agreement are conceded orundertaken, and that it is not for one contractingparty to determine what is or is not essential in theeyes of the other. It is impossible to escape altogetherfrom these difficulties. It is useless to endeavour totie the hands of dishonest states beyond power ofescape. All that can be done is to try to find a testwhich shall enable a candid mind to judge whetherthe right of repudiating a treaty has arisen in a givencase. Such a test may be found in the main object ofa treaty. There can be no question that the breachof a stipulation which is material to the main object,or if there are several, to one of the main objects, libe-rates the party other than that committing the breachfrom the obligations of the contract; but it would beseldom that the infraction of an article which is eitherdisconnected from the main object, or is unimportant,whether originally or by change of circumstances, withrespect to it, could in fairness absolve the other partyfrom performance of his share of the rest of theagreement. . . . "

The previous Special Rapporteur, as mentioned in para-graph 5 above, defined a " fundamental " breach as one" going to the root or foundation of the treaty rela-tionship between the parties and calling in question thecontinued value or possibility of that relationship in theparticular field covered by the treaty ". This definitionand the further qualifications put upon it by the previousSpecial Rapporteur seem perhaps to put the concept ofa *' fundamental " breach rather high. The present draft,though inspired by the same general considerations,seeks to define a "material " breach of a treaty by refe-rence to the attitude adopted by the parties with regardto reservations at the time when they concluded the treaty;and, if they said nothing about reservations at that time,then by reference to the " object and purpose " of thetreaty— the criterion used for determining the powerto make reservations in such a case.126 The reason, ofcourse, is that, although the two questions are notidentical, there is a certain connexion between theviews of the contracting States concerning the making ofreservations and their views concerning what are to beregarded as material breaches of the treaty. It thereforeseemed logical, in formulating the present article, to takeinto account the rules regarding the making of reserva-tions provisionally adopted by the Commission in ar-ticle 18 of part I.13. The definition of " material " breach in paragraph2 has three clauses. Sub-paragraph (a) gives the repudia-tion of the treaty as the first and most obvious form ofmaterial breach. Although the point is obvious, it needsto be stated, if only to underline that the repudiationof a treaty by one party does not of itself terminate itsobligations under the treaty. If that were true, as waspointed out by Vattel,127 " engagements could readilybe set aside and treaties would be reduced to empty for-malities ". The main definition is in sub-paragraph (b),

126 See generally the Commentary to article 18 of thepresent Special Rapporteur 's first report (A /CN.4 /144) .

127 The Law of Nations, Book IV, chapter IV, Section 54.

and under it the concept of a " material " breach con-tains two restrictive elements: the breach must be " sub-stantial ", so as to amount to a setting aside of the par-ticular provision by the defaulting party; and the provi-sion must be one apparently regarded by the parties as anecessary condition of their entering into the treaty. Thelatter point, however, is stated in as objective terms aspossible by linking it, for the reasons explained in theprevious paragraph, to the conditions under which thetreaty permits reservations to be made. Where the treatyis silent as to the power to make reservations then thetest, as in article 18 of the present Special Rapporteur'sfirst report (A/AC.4/144), is compatibility with theobject and purpose of the treaty. Sub-paragraph (c), inorder to remove any doubts of the kind mentioned inparagraph 11 of the present Commentary, specifies that,where the treaty expressly provides for compulsory refe-rence of disputes arising out of it to arbitration or judi-cial settlement, disregard of that provision will constitutea material breach.14. Paragraph 3 sets out the rights of the innocentparty in case of a material breach of a bilateral treaty.These are to abrogate the whole treaty or suspend itswhole operation or, alternatively, to terminate or sus-pend the operation only of the provision which hasbeen broken by the defaulting party. The latter right,like the former, is an application of the principle ina-dimplenti non est adimplendum, endorsed by JudgeAnzilotti in the Diversion of Water from the RiverMeuse case.128 Admittedly, it may also be put upon thebasis of a right to take non-forcible reprisals and uponthat basis it is arguable that the innocent party may sus-pend the operation not necessarily of the provision whichhas been broken of but some other provision of specialconcern to the defaulting party. The terms of para-graph 2 are not intended to exclude whatever otherrights may accrue to the innocent party by way or repri-sal; but it is thought better not to introduce the law ofreprisals, as such, into the present article. Naturally, anyabrogation or suspension of the whole or part of thetreaty under paragraph 3 will be without prejudice tothe innocent party's right to claim compensation forany loss or damage resulting from the breach.15. Paragraph 4 sets out in a parallel manner therights of the other parties in the case of a material breachof a multilateral treaty, with the difference that normallyan individual innocent party is not in a position to ter-minate the treaty, or suspend its operation, generallyas between all the parties. Its right is normally limitedto terminating or suspending the treaty or one of itsprovisions as between itself and the defaulting State. Thepresent draft does not take as its basis the division ofmultilateral treaties into different categories by referenceto the nature of their obligations, which was a centralfeature of the previous Special Rapporteur's proposals(see paragraph 6 above). While not in any way wishingto minimize the general significance of the distinctionswhich he draws between the different kinds of obligationthat may be contained in multilateral treaties, the presentSpecial Rapporteur doubts whether, as the law standstoday, they can be said to be of decisive importance inthe present connexion. However true it may be thatlaw-making treaties, treaties creating international re-gimes for particular areas and certain other types of

128 See paragraph 4 of this Commentary.

Law of Treaties 77

treaty may establish obligations of an objective character,there remains a contractual element in the legal relationcreated by the treaty between any two parties. No doubt,if one party violates the treaty, another innocent partycannot, as a rule, individually release itself on thataccount from its obligations under the treaty because ofits undertakings to the remaining contracting parties. Butit is quite another thing to say that it is bound, howeversubstantial and persistent the violation, to continue intreaty-relations with the defaulting State and remainliable to the latter for any non-performance affecting itsinterests. Quite apart from the essentially bilateral cha-racter of many of the rights and obligations created bylaw-making treaties and by international regimes, sucha rule hardly seems possible until the remedies forbreaches of international law are more highly organizedand certain. The mere fact that many such treatiesexpressly contemplate their own denunciation, whileothers contemplate the expulsion of aconvenant-breakingState,120 makes it doubtful whether such a rule wouldbe in harmony with existing principles, however desirableit may be that international law should one day be in aposition to adopt such a rule. In the cases distinguishedby the previous Special Rapporteur, an innocent partymay well be less inclined to terminate the treaty-rela-tion in consequence of the breach, but to forbid it to doso is almost to protect the covenant-breaking State inits wrong-doing.16. The primary distinction made in the present draftis between a multilateral treaty pure and simple and amultilateral treaty which is the constituent instrument ofan international organization or that has been concluded— like international labour conventions — within aninternational organization. Paragraph 4 deals with ordi-nary multilateral treaties and paragraph 5 with consti-tuent treaties and treaties concluded within an organiza-tion.17. Paragraph 4 (a) provides that in the case of amaterial breach an individual party may break off orsuspend the treaty relation as between itself and thedefaulting State or do the same with regard only to theprovision which is the subject of the breach; in otherwords, it provides in the bilateral relationships betweenparties to a multilateral treaty for rights correspondingto those which exist in the case of a bilateral treaty. Ifindividual States react against a material breach by ter-minating the treaty link between them and the defaultingState, the treaty remains in force as between the latterand the other parties to the treaty. It is conceivable,however, that, because of the key position held by thedefaulting State in the whole regime of the treaty, orbecause of the number of parties implicated in thebreach, the general body of the parties to the treatymight wish to terminate or suspend the whole treaty. Inthat event, their natural course would seem to be toproceed to terminate or suspend the treaty by subse-quent agreement under article 18, and this course isaccordingly indicated in paragraph 4 (b). But in casessuch as these, where the defaults of a key State or of anumber of States go far to undermine the whole treaty

129 Even a treaty like the European Convention of HumanRights, designed for the protection of the individual, is sub-ject to denunciation, while a party which ceases to be a mem-ber of the Council of Europe automatically ceases to be aparty to the treaty.

regime, it seems desirable that individual parties shouldalso have the right not merely of terminating their treaty-relation with the defaulting State but of withdrawingaltogether from the treaty. A proviso has accordinglybeen added to paragraph 4 recognizing such a right incases where the breach has the effect of frustrating theobject and purpose of the treaty also in the relationsbetween the States not involved in the breach.18. A plausible case could, perhaps, be made out infavour or recognizing a right in the other parties to thetreaty collectively, by a two-thirds majority, to declarethe defaulting State to be no longer a party — of expel-ling it from the regime of the treaty, just as in some inter-national organizations the members may expel a Statewhich persistently violates the obligations incumbentupon a member. The position is different, however, inthe case of an international organization, because nor-mally the members cannot by their individual actionterminate their relations with the defaulting State withinthe organization. They can only do so by a collectivedecision. The fact that any party to a multilateral treatycan individually put an end to the treaty relation betweenitself and the defaulting State removes the need tolegislate for the possibility of a collective expulsion ofthe treaty-breaking State.19. Paragraph 5 provides that in the case of the mate-rial breach of a constituent treaty of an internationalorganization the termination or suspension of the rightsor obligations of the parties under the treaty shall inprinciple be matter for decision by the competent organin accordance with the applicable rules of the constitu-tion of the organization in question. The constitutionsof many of the larger organizations contain provisionsrelating to the suspension or termination of membershipor to the suspension of voting rights in the event of amember's being in default in its obligations and as men-tioned in paragraph 20 of the Commentary to article 17,many of them provide for a right to denounce or with-draw from the treaty. In these cases, it seems clear thatany question of terminating or suspending the member-ship of the defaulting party or of suspending generallythe operation of a provision of the treaty must be one forthe competent organ of the Organization and not forthe individual parties to the treaty. Similarly, in the caseof treaties, such as international labour conventions,concluded within an organization, the reaction of theparties to a material breach is essentially a matter to besettled within the organization. Admittedly, some of themore loosely knit organizations contain no provisionsconcerning termination or suspension of membership,or concerning withdrawal from the organization; and insome cases the only form of common organ they envis-age is the occasional calling of a conference of the mem-bers. Even in such cases, however, it would seem that theexpulsion of a party from the treaty regime or the ter-mination or suspension of the treaty should, in principle,be questions for some form of " collegiate " decisionwithin the organization.

Article 21 —Dissolution of a treaty in consequence ofa supervening impossibility or illegality of performance

1. (a) Subject to the rules governing State successionin the matter of treaties, if the international personality ofone of the parties to a treaty is extinguished, any otherparty may invoke the extinction of such party —


(i) in the case of a bilateral treaty, as having dissolvedthe treaty;

(ii) in other cases as having rendered the treaty inappli-cable with respect to the extinguished State;

provided always that the extinction of such party wasnot brought about by means contrary to the provisionsof the Charter of the United Nations.

(b) In a case falling under sub-paragraph (a) (ii),if the extinction of the party in question materiallyaffects the fulfilment of the object and purpose of thetreaty as between the remaining parties, it may beinvoked by any such party as a ground for withdrawingfrom the treaty.

2. It shall be open to any party to call for the termina-tion of a treaty if after its entry into force its perform-ance shall have become impossible owing to —

(a) the complete and permanent disappearance ordestruction of the physical subject-matter of the rightsand obligations contained in the treaty; provided alwaysthat it was not the purpose of the treaty to ensurethe maintenance of the subject-matter;

(b) the complete and permanent disappearance of alegal arrangement or regime to which the rights andobligations established by the treaty directly relate.

3. If in a case falling under paragraph 2 there is sub-stantial doubt as to whether the cause of the impossibilityof performance will be permanent, the treaty may onlybe suspended, not terminated. In that event, the opera-tion of the treaty shall remain in suspense until the im-possibility of performance has ceased or, as the casemay be, has to all appearances become permanent.

4. It shall also be open to any party to call for thetermination of a treaty, if after its entry into force theestablishment of a new rule of international law havingthe character of jus cogens shall have rendered the per-formance of the treaty illegal under international law.

Commentary1. This article and article 22 cover the dissolution orsuspension of treaties by reason of events or develop-ments subsequent to their conclusion. Under the pre-vious articles of the present section, the termination ofa treaty comes about either by its own terms or throughthe exercise by one of the parties of a right expressly orimpliedly contained in it or through the exercise of aright arising out of the breach of the treaty. Under thisand the next article it comes about through events ordevelopments which occur outside the treaty, and it isoften spoken of as happening by operation of law inde-pendently of the will of the parties. Some authorities, itis true, put these cases upon the ground of an impliedresolutory condition, saying that every treaty is to under-stood as subject to a condition as to the continuedpossibility and legality of its performance and as to thecontinued existence, without essential change, of thecircumstances upon which the treaty was based. Butunder that theory also the termination of the treaty will,in principle, be automatic and come about independentlyof the will of the parties by the happening of eventsresulting in an impossiblity or illegality of performanceor a fundamental change in the circumstances.

2. It is true that in the cases dealt with in articles 21and 22 the termination of the treaty might be re-garded as taking place by operation of law, independent-

ly of any expression of will by the parties, when theterminating events or developments have occurred. Butdisputes may arise as to whether these events ordevelopments have in fact occurred, just as in cases of" essential validity " disputes may arise as to theexistence of the alleged ground of invalidity. As insection III, so also in these articles the absence ofany general system of compulsory adjudication makesit difficult to adopt the principle of automatic annul-ment of the treaty by operation of law without anyqualification. Otherwise, and especially with regard tothe doctrine of rebus sic stantibus, there is a danger ofa legitimate and relevant principle of law being usedas a mere pretext for repudiating treaty obligations. It isfor this reason that the present article and article 22have been formulated in terms of the right of a party todenounce the treaty, rather than in terms of the auto-matic extinction of the treaty by operation of law; andfor the same reason the right to claim that the treatyhas been dissolved on one or other of the grounds men-tioned in these articles is brought by article 4 under theprocedural requirements of section IV. The upshot isthat the cases arising under these articles are dealt withon the same lines as cases of essential validity and casesof termination following upon breach.3. Supervening impossibility or illegality of perfor-mance are necessarily cases where there is a fundamentalchange in the circumstances on the basis of which theparties entered into the treaty; and they could accord-ingly be regarded as falling within the general scope ofthe doctrine of rebus sic stantibus. The special Rappor-teur, however, agrees with his predecessor 130 in thinkingthat supervening impossibility and illegality of perfor-mance are distinct grounds for the dissolution of treatieshaving a juridical basis that is independent of the doc-trine of rebus sic stantibus. Moreover, they are groundsfor regarding a treaty as dissolved which are both morespecific and leave much less room for subjective appre-ciation than the rebus sic stantibus doctrine. It thereforeseems advisable to keep them apart from that doctrine,which is, in consequence, dealt with separately in ar-ticle 22.4. Paragraph 1 considers the special case of impossibi-lity of performance brought about by the disappearanceof one of the parties. This case is treated by most ofthe authorities as one of the instances of impossibility ofperformance, and it was so treated by the previousSpecial Rapporteur, altough he recognized that it mustbe subject to the law governing State succession in thematter of treaties. His draft article 17, paragraph I A (i),read:

" Total extinction of one of the parties to a bilateraltreaty, as a separate international personality, or lossor complete change of identity, subject however tothe rules of State succession in the matter of bilateraltreaties where these rules provide for the devolutionof treaty obligations."

Owing to the links between this question and the ques-tion of State succession, which is being taken up sepa-rately by the Commission, the present Special Rappor-teur felt some hesitation in including paragraph 1 of thepresent article. However, where succession does not

130 Sir G. Fitzmaurice's second report (A/CN.4/107),article 17, and commentary, paragraphs 100-102.

Law of Treaties 79

take place, the extinction of a party is a ground for theautomatic dissolution of a treaty or, in the case of amultilateral treaty, for the application of the treaty tocease with respect to the extinguished State 131 Accord-ingly, paragraph 1 has been included in order that thepoint may be considered by the Commission. If para-graph 1 is included, it seems appropriate to reserve fromit the case of a State extinguished by means contrary tothe Charter. Sub-paragraph (b) has been added to coverthe possible case of the extinction of a party to a treatyconcluded amongst a small group of States, in whichevent the disappearance of one party might largelyimpair the usefulness of the treaty.5. Paragraph 2 covers cases where the treaty is literallyimpossible to perform by reason of the disappearanceof its subject-matter. This may happen in two ways,either through the disappearance of the physical subjectof the rights and obligations of the treaty or throughthe disappearance of a legal state of affairs which wasthe raison d'etre of those rights and obligations. Theformer type is defined in sub-paragraph 2 (a), andexamples of it are easier to imagine than to find inpractice. Amongst the theoretical possibilities suggestedby the previous Special Rapporteur were: the submer-gence of an island, the drying up of a river bed, thedestruction of a railway by an earthquake, the destruc-tion of plant, installations, a canal, lighthouse, etc.132

No doubt, any of these things may happen, but noneof them has so far given rise to a leading case ordiplomatic incident concerning the dissolution of treaties.As the previous Special Rapporteur pointed out, it isnecessary to distinguish cases where the maintenanceof the particular subject-matter was the express objectof the treaty, e.g. a treaty concerning the maintenanceof a lighthouse or other navigational aid, where theremay be a duty to replace the lost or destroyed object.6. The second type of case, which is defined in sub-paragraph 2 (b), is where a treaty relates to a legalarrangement or regime which is afterwards abolished,when the treaty necessarily ceases to be capable ofperformance and devoid of object. Examples aretreaties relating to the operations of capitulations, whichnecessarily fell to the ground as each system of capitula-tions was finally and, to all appearances, permanentlyabolished. Other examples given by the previous SpecialRapporteur (A/CN.4/107, paragraph 101) were treatiesrelating to a customs union or condominium whichwould also necessarily become incapable of performanceif the customs union or condominium disappeared alto-gether. These examples appear to be genuine cases ofimpossibility of performance by reason of the disappear-ance of the subject-matter of the treaty similar to thedisappearance of an island, river, etc. The previousSpecial Rapporteur formulated his rule rather morebroadly as covering any case of " Supervening literalinapplicability owing to disappearance of the treaty fieldof action "; and he included under this head such casesas Great Britain's declaration in 1921 that she regardedher bilateral treaties for combatting the slave trade asterminated since there was no longer any slave trade

1 :1 See Harvard Law School, Research in InternationalLaw, III, Law of Treaties, pp. 1165-1168; F. I. Kozhevnikov,International Law (Academy of Sciences of the USSR), p. 281.

132 Second report (A/CN.4/107, paragraph 97). See alsoMcNair, op. cit., p. 685.

to combat. This seems to be more a case of desuetudethan of impossibility of performance, and the presentSpecial Rapporteur prefers to confine the present articleto what are strictly cases of physical or legal impos-sibility of performance. Otherwise it may be difficultto separate the cases falling under the present articlefrom those falling under the doctrine of rebus sic stan-tibus.7. Paragraph 3 provides that where there is an impos-sibility of performance the permanence of which isdoubtful, the treaty may only be suspended, not ter-minated. These cases, it is true, might simply be treatedas cases where force majeure could be pleaded as adefence exonerating a party from liability for non-performance. But where there is a continuing impos-sibility of performance of continuing obligations itseems better to recognize that the treaty may be sus-pended. It should, perhaps, be added that one obviouscase of impossibility, namely impossibility resultingfrom the outbreak of hostilities, does not fall undereither paragraphs 2 or 3, and is not covered by thepresent article. The effect of war on treaties raises specialissues and is not covered by the present report.

8. Paragraph 4 covers cases of impossibility arisingfrom changes in the law itself and in the nature ofthings these are not likely to be very common in interna-tional law. A new inconsistent treaty may dissolve anearlier one between the same parties, but the processis properly to be regarded as one of implied abrogationby the parties, rather than of dissolution by operationof law; accordingly, such a case falls not under thepresent article but under article 14. The present articledeals rather with an illegality arising from the emer-gence of a new rule of jus cogens. Then it is not simplya question of the priority to be given to two equallyvalid norms; for the emergence of the new rule of juscogens renders the earlier treaty illegal and incapable ofperformance within the law. An example would beformer treaties not to combat but to regulate the slavetrade, some of which were concluded even in thenineteenth century.133 The subsequent condemnation ofall forms of slavery by general international lawultimately rendered such treaties incapable of appli-cation. Another illustration often given in the booksis treaties concerning facilities for privateers concludedbefore the abolition of privateering.134

Article 22 — The doctrine of rebus sic stantibus

1. (a) A change in the circumstances which existed atthe time when a treaty was entered into does not, assuch, affect the continued validity of the treaty.

(b) Under the conditions set out in the followingparagraphs of this article, however, the validity of atreaty may be affected by an essential change in thecircumstances forming the basis of a treaty.2. An essential change in the circumstances formingthe basis of a treaty occurs when:

(a) a change has taken place with respect to a factor state of facts which existed when the treaty wasentered into;

(b) it appears from the object and purpose of the

133 e.g., article 4 of the Anglo-Portuguese Treaty of22 January 1815; see McNair, op. cit., p. 685.

13-1 See Oppenheim, op. cit., p. 946.


treaty and from the circumstances in which it was enteredinto, that the parties must both, or all, have assumedthe continued existence of that fact or state of facts tobe an essential foundation of the obligations acceptedby them in the treaty; and

(c) the effect of the change in that fact or state offacts is such as —(i) in substance to frustrate the further realization of

the object and purpose of the treaty; or(ii) to render the performance of the obligationscontained in the treaty something essentially differentfrom what was originally undertaken.3. A change in the policies of the State claiming toterminate the treaty, or in its motives or attitude withrespect to the treaty, does not constitute an essentialchange in the circumstances forming the basis of thetreaty within the meaning of paragraph 2.4. An essential change in the circumstances formingthe basis of a treaty may not be invoked for the purposeof denouncing or withdrawing from a treaty if —

(a) it was caused, or substantially contributed to, bythe acts or omissions of the party invoking it;

(b) the State concerned has failed to invoke it withina reasonable time after it first became perceptible, orhas otherwise precluded itself from invoking the changeof circumstances under the provisions of article 4 of thispart;

(c) such change of circumstances has been expresslyor impliedly provided for in the treaty itself or in asubsequent agreement concluded between the parties inquestion.5. An essential change in the circumstances formingthe basis of a treaty may not be invoked for the purposeof terminating —

(a) stipulations of a treaty which effect a transfer ofterritory, the settlement of a boundary, or a grant ofterritorial rights;

(b) stipulations which accompany a transfer of terri-tory or boundary settlement and are expressed to be anessential condition of such transfer or settlement;

(c) a treaty which is the constituent instrument of aninternational organization.6. A party shall only be entitled to terminate or with-draw from a treaty on the ground of an essential changein the circumstances forming the basis of the treaty —

(a) by agreement under the provisions of articles 18and 19; or

{b) under the procedure laid down in article 25.

Commentary1. Almost all modern writers,135 however reluctantly,admit the existence in international law of the principlewith which this article is concerned and which is com-monly spoken of as the doctrine of rebus sic stantibus.Just as many systems of municipal law recognize that,quite apart from any actual impossibility of perfor-mance, contracts may become inapplicable through afundamental change of circumstances, so also, it is held,

international law recognizes that treaties may cease tobe binding upon the parties for the same reason. Mostwriters, however, at the same time enter a strong caveatas to the need to confine the scope of the doctrinewithin narrow limits and to regulate strictly the condi-tions under which it may be invoked; for the risks to thegeneral security of treaties which this doctrine presentsin the absence of any general system of compulsoryjurisdiction are even more serious than in the case ofdenunciation on the ground of an alleged breach of thetreaty or in the case of any other ground either ofinvalidity or of termination. As was said by the previousSpecial Rapporteur in his second report (A/CN.4/107,paragraph 142):

" It is all too easy to find grounds for alleging achange of circumstances, since in fact in internationallife circumstances are constantly changing. But thesechanges are not, generally speaking, of a kind that canor should affect the continued operation of treaties.As a rule, they do not render the execution of thetreaty either impossible or materially difficult, or itsobjects impossible of realization, or destroy its valueor raison d'etre. What they may tend to influence isthe willingness of one or other of the parties, onideological or political grounds — often of aninternal character — to continue to carry it out."

Tn short, this ground for obtaining release from treatyobligations is susceptible of being used even moreflexibly and more subjectively than any of the others.2. Despite the almost universal distrust of the doctrineand despite the differences of opinion which exist inregard to some aspects of it, there is a good deal ofevidence of its recognition in customary law. The Inter-national Court, it is true, has not yet committed itselfon the point. In the Free Zones case,136 having heldthat the facts did not in any event justify the applica-tion of the doctrine, the Permanent Court expresslyreserved its position. It observed that it became unne-cessary for it to consider " any of the questions ofprinciple which arise in connexion with the theoryof the lapse of treaties by reason of change of circum-stances, such as the extent to which the theory can beregarded as constituting a rule of international law, theoccasions on which and the methods by which effectcan be given to the theory, if recognized, and the ques-tion whether it would apply to treaties establishingrights such as that which Switzerland derived from thetreaties of 1815 and 1816 ". On the other hand, it canequally be said that the Court has never on any occa-sion m rejected the doctrine and that in the passage justquoted it even seems to have assumed that the doctrineis to some extent admitted in international law.Sir H. Lauterpacht138 thought it to be clear from thispassage that the Court was " prepared to recognize theprinciple, although it refused to say to what extent ".This statement seems, however, to go rather far, sincethe Court in dealing with the facts underlined that it

135 e.g., Oppenheim, op. cit., Vol. I, pp. 938-944; McNair ,op. cit., pp. 681-691; F . I. Koshevnikov, op. cit., p. 281; C.Rousseau, Principes generaux du droit international public,tome I, pp. 580-615; Harvard Law School, Research in Inter-national Law, III, Law of Treaties, pp. 1096-1126; ChesneyHill , The Doctrine of Rebus Sic Stantibus, University ofMissouri Studies (1934).

136 P.C.I.J. Series A / B N o . 46, pp. 156-8.137 e.g., in the Nationality Decrees Opinion (P.C.I.J.,

Series B, N o . 4, p . 29), where it merely observed that it wouldbe impossible to pronounce upon the point raised by Franceregarding the " principle known as the clausula rebus sicstantibus " without recourse to the principles of internationallaw concerning the durat ion of treaties.

338 The Development of International Law by the Inter-nationa! Court, p . 85.

Law of Treaties 81

was confining itself to the case as it had been arguedby France, without taking any position as to how farthat case might or might not be well founded in law.3. Municipal courts, on the other hand, have notinfrequently recognized the relevance of the rebus sicstantibus doctrine in international law, though for onereason or another they have always ended by rejectingthe application of the doctrine in the particular circum-stances of the case before them.139 These cases empha-size that the doctrine is limited to changes in circum-stances the continuance of which, having regard to theevident intention of the parties at the time, was regardedas a tacit condition of the agreement;140 that the treatyis not dissolved automatically by law upon the occur-rence of the change but only if the doctrine is invokedby one of the parties,141 and that the doctrine mustbe invoked within a reasonable time after the changein the circumstances was first perceived.142 Moreover,in Bremen v. Prussia 143 the German Reichsgericht, whilenot disputing the general relevance of the doctrine,considered it altogether inapplicable to a case whereone party was seeking to release itself not from thewhole treaty but only from certain restrictive clauseswhich had formed an essential part of an agreementfor an exchange of territory.

4. The doctrine of rebus sic stantibus has not infre-quently been invoked in State practice either eo nomineor in the form of a reference to a general principle claim-ed to justify the termination or modification of treatyobligations by reason of changed circumstances. Detailedexamination of this State practice is not possible in thepresent report.144 Broadly speaking, it shows a wideacceptance of the view that a fundamental change ofcircumstances may justify a demand for the terminationor revision of a treaty, but also shows a strong disposi-tion to question the right of a party to denounce a treatyunilaterally on this ground. The most significant indica-tions as to the attitude of States regarding the doctrineare perhaps to be found in statements submitted to theCourt in the cases where the doctrine has been invoked.In the Nationality Decrees case the French Governmentcontended that " perpetual " treaties were always subjectto termination in virtue of the rebus sic stantibus clauseand claimed that the establishment of the French pro-tectorate over Morocco had for that reason had theeffect of extinguishing certain Anglo-French Treaties.145

139 e.g., Hooper, v. United States, Hudson , Cases on Inter-national Law, second edition, p . 930; Lucerne v. Aargau(1888), Arrets du Tribunal Federal Suisse, Vol . 8, p . 57; Inre Lepeschkin, Annual Digest of Public International LawCases, 1923-1924, Case N o . 189; Bremen v. Prussia, Ibid.,1925-1926, Case N o . 266; Rothschild and Sons v. EgyptianGovernment, Ibid., 1925-1926, Case N o . 14; Canton of Thur-gau v. Canton of St. Gallen, Ibid., 1927-1928; Case N o . 289;Bertaco v. Bancel, Ibid., 1935-1937, Case N o . 2 0 1 ; Stranskyv. Zivnostenska Bank, International Law Reports, 1955,pp. 424-427.

140 Lucerne v. Aargau; Canton of Thurgau v. Canton ofSt. Gallen; Hooper v. United States.

111 In re Lepeschkin; Stransky v. Zivnostenska Bank.112 Canton of Thurgau v. Canton of St. Gallen.143 Annual Digest of Public International Law Cases,

1925-1926, Case No. 266.114 See the accounts of State practice in Chesney Hill, op.

cit., pp. 27-74; C. Kiss, op. cit., pp. 381-393; C. Rousseau,op. cit., pp. 594-615; Harvard Law School, Research in Inter-national Law, III, Law of Treaties, pp. 1113-1124; H. W.Briggs. A.J.I.L. 1942, pp. 89-96, and 1949, pp. 762-769.

145 P.C.I.J. Series C, No. 2, pp. 187-188.

The British Government, while contesting the FrenchGovernment's view of the facts, observed that the mostforceful argument advanced by France was that ofrebus sic stantibus.146 In the case concerning TheDenunciation of the Sino-Belgian Treaty of 1865, Chinainvoked, in general terms, changes of circumstances asa justification of her denunciation of a sixty-year-oldtreaty, and supported her contention with a referenceto Article 19 of the Covenant.147 This Article, however,provided that the Assembly of the League should " fromtime to time advise the reconsideration by Membersof the League of treaties which have become inappli-cable", and the Belgian Government was not slow toreply that neither Article 19 nor the doctrine of rebussic stantibus contemplated the unilateral denunciationof treaties. It further maintained that there could be noquestion of China's denouncing the treaty because ofa change of circumstances unless she had at least triedto obtain its revision through Article 19; that whereboth parties were subject to the Court's jurisdiction,the natural course for China, in case of dispute, was toobtain a ruling from the Court; and that if she didnot, she could not denounce the treaty without Belgium'sconsent.148 Even more striking, in the Free Zonescase,14y the French Government, the Government invok-ing the rebus sic stantibus doctrine, itself emphasizedthat the doctrine did not allow unilateral denunciationof a treaty claimed to be out of date. It argued that thedoctrine would cause a treaty to lapse only " lorsquele changement de circonstances aura ete reconnu parun acte faisant droit entre les deux Etats interesses ";and it further said: " cet acte faisant droit entre lesdeux Etats interesses peut etre soit un accord, lequelaccord sera une reconnaissance du changement des cir-constances et de son effet sur le traite, soit une sentencedu juge international competent s'il y en a un ".150

Switzerland, emphasizing the differences of opinionamongst writers in regard to the doctrine, disputed theexistence in international law of any such right to thetermination of a treaty because of changed circum-stances enforceable through the decision of a competenttribunal. But she rested her case primarily on three

contentions: (a) the circumstances alleged to havechanged were not circumstances on the basis of whosecontinuance the parties could be said to have enteredinto the treaty; (b) in any event, the doctrine does notapply to treaties creating territorial rights; and (c) Francehad delayed unreasonably long after the alleged changesof circumstances had manifested themselves.151 Francedoes not appear to have disputed that the doctrine isinapplicable to territorial rights; instead, she drew adistinction between territorial rights and " personal "rights created on the occasion of a territorial settle-ment.1'2 The Court upheld the Swiss Government'scontentions on points (a) and (c), but did not pronounceon the application of the rebus sic stantibus doctrine totreaties creating territorial rights.

»" Ibid., pp. 208-209.*" ibid.. No. 16, I, p. 52.148 Ibid., pp. 22-23; the case was ultimately settled by the

conclusion of a new treaty.i4» Ibid., Series A/B, No. 46.150 Ibid., Series C, No. 58, pp. 578-579, 109-146, and

405-415; see also Series C, No. 17, I, pp. 89, 250, 256,283-284.

" I Ibid., Series C, No. 58, pp. 463-476.152 ibid., pp. 136-143.


5. Brief reference may also be made to two instancesin which the rebus sic stantibus doctrine has been raisedin political organs of the United Nations. In 1947 Egyptreferred to the Security Council the question of thecontinued validity of the Anglo-Egyptian Treaty of1936,153 using arguments which, without mentioning iteo nomine, were based upon the rebus sic stantibusdoctrine. No resolution was adopted; but several repre-sentatives expressed objection to an interpretation of therebus sic stantibus doctrine which would allow a purelyunilateral denunciation of a treaty without some form ofadjudication upon the merits of a claim to invoke thatdoctrine. The second instance concerns a study, pre-pared by the Secretary-General at the request of theEconomic and Social Council, of the present legalvalidity of the undertakings relating to the protectionof minorities placed under the guarantee of the Leagueof Nations. The Secretary-General, while emphasizingits limited character, assumed the rebus sic stantibusdoctrine to be applicable in international law (E/CN.4/367, p. 37):

" International law recognizes that in some casesan important change of the factual circumstancesfrom those under which a treaty was concluded maycause that treaty to lapse. In such cases the clauserebus sic stantibus applies if invoked by the Govern-ments.

" But if international law recognizes the clauserebus sic stantibus, it only gives it a very limitedscope and surrounds it with restrictive conditions, somuch so that the application of the clause acquires anexceptional character."

Having mentioned the differences of opinion concerningthe conditions for the application of the doctrine, theSecretary-General said that for the purposes of thestudy he would be guided by a restrictive definition ofthe doctrine, without suggesting that it was necessarilythe one which should be adopted by internationaltribunals. On this basis, he stated that the doctrinerequires that (1) certain factual conditions, which existedat the moment of the conclusion of the treaty and inthe absence of which the parties would not haveconcluded the treaty, should have disappeared; (2) thenew circumstances should differ substantially from thosewhich existed at the time when the treaty was concluded,so as to render its application morally and physicallyimpossible; and (3) the State invoking the clause shouldobtain the consent of the other contracting parties and,in the absence of such consent, should secure recogni-tion of the validity of its claim by a competent interna-tional organ, such as one of the executive organs of theUnited Nations or the International Court of Justice.The general conclusion of the study was that the par-ticular changes of circumstances with respect to eachcountry concerned did not warrant the application ofthe doctrine; but that between 1939 and 1947 circum-stances as a whole had changed to such an extent withregard to the system of protection of minorities thatthe undertakings given by States during the Leagueperiod should be considered as having ceased to exist.This study was, of course, an objective, non-conten-tious, examination of the particular problem, and nodoubt it was for that reason that the question of the

consent of the interested parties was not taken intoconsideration by the Secretary-General in arriving athis general conclusions.6. The controversy that surrounds the doctrine and thedangers that it causes for the security of treaties justifysome hesitation on the part of the Commission inincluding it in the draft articles on the law of treaties.Nevertheless, on balance, the Special Rapporteur agreeswith his predecessor (A/CN.4/107, paragraph 144) inthinking that, carefully delimited and regulated, it shouldbe included. A treaty may remain in force for genera-tions and its stipulations come to place an undue burdenon one of the parties. Then, if the other party is obdu-rate in opposing any change, the fact that internationallaw recognized no legal means of terminating ormodifying the treaty otherwise than through a furtheragreement between the same parties may impose aserious strain on the relations between the Statesconcerned. It may be better to try and fill this gap inthe law even by a legal institution so imperfect as therebus sic stantibus doctrine, rather than to leave thatdissatisfied State ultimately to release itself from thetreaty by means outside the law. It is true that thenumber of such cases is likely to be comparatively small.As pointed out in the Commentary to article 15, themajority of modern treaties are expressed to be of shortduration, or are entered into for recurrent terms ofyears with a right to break the treaty at the end ofeach term, or are expressly or implicitly terminable uponnotice. In all these cases either the treaty expires auto-matically or each party, having the power to terminatethe treaty, has the power also to apply pressure uponthe other party to revise its provisions. Further, evenwhen a treaty is not subject to early termination in anyof these ways, the parties may be ready to agree uponthe termination or revision of an out-of-date treaty.Nevertheless, there remains a residue of cases in which,failing any agreement, one party may be left powerlessunder the treaty to obtain any relief from outmoded andburdensome provisions. It is in these cases that therebus sic stantibus doctrine may be required, not neces-sarily to effect the termination of the treaty, but as alever to induce a spirit of compromise in the otherparty. Moreover, despite the strong reservations oftenexpressed with regard to it, the evidence of the acceptanceof the doctrine in international law is so considerablethat it seems to indicate a general belief in the need fora safety-valve of this kind in the law of treaties.

7. Various theories have been advanced concerningthe juridical basis of the doctrine,154 three of whichwere isolated by the previous Special Rapporteur fordetailed examination (A/CN.4/107, paragraphs 146-148):(i) Under this theory the parties are presumed to have

had in mind the continuance of certain circum-stances as the basis of their agreement and to haveintended the treaty to be subject to an impliedcondition by which it is to come to an end if thereis an essential change in those circumstances.

(ii) Under the second theory, international law isconsidered to impose upon the parties to a treatyan objective rule of law prescribing that an essential

133 Treaty of Friendship and Alliance, London, 26 August1936, United Kingdom Treaty Series No. 6 (1937).

154 See Chesney Hill, op. cit., pp. 7-16; C. Rousseau, op.cit.. pp. 580-586.

Law of Treaties 83

change of circumstances entitles any of the partiesto require the termination of the treaty,

(iii) Under the third theory, which is a mixture of thefirst two, the doctrine is considered to be an objec-tive rule of law the operation of which is to importinto the treaty, regardless of the intention of theparties, an implied condition that it will come toan end if there is an essential change of circum-stances.

The previous Special Rapporteur thought there is to be acrucial point of difference between the second and thirdtheories. If the rule of law is considered to operate byinserting an implied condition in the treaty, the ter-mination of the treaty will occur automatically whenan essential change of circumstances takes place, whereasunder the second theory the rule operates only to confera right to call for the termination of the treaty. Thedifference between the two theories may not be so greatin practice, since under either theory the really criticalpoint is whether one party may unilaterally determinewhether or not an essential change has occurred. If apurely unilateral power of determination is not admitted,the practical effect of the two theories is not verydifferent. However, the present Special Rapporteuragrees with his predecessor in thinking that the thirdtheory is not an improvement on the second and shouldbe left aside.8. The Special Rapporteur likewise agrees with hispredecessor in recommending that the Commissionshould base itself upon the second rather than the firsttheory; that is, upon the view that the rebus sic stan-tibus doctrine is an objective rule of law rather than apresumption as to the original intention of the partiesto make the treaty subject to an implied condition.True, the theory of an implied clausula rebus sic stan-tibus has a long history going back, according to onewriter,155 to St. Thomas Aquinas, and the great majorityof writers have presented the doctrine in the form ofa term implied in every perpetual treaty. But, as waspointed out by the previous Special Rapporteur, thetendency today is to regard the implied term as only afiction by which it is attempted to reconcile the dissolu-tion of treaties in consequence of a fundamental changeof circumstances with the rule pacta sunt servanda. Inmost cases the parties have given no thought to thepossibility of a change of circumstances and, if theyhad done so, would probably have provided for it ina different manner. Furthermore, the fiction is consideredan undesirable one since, by making the doctrinedependent upon the the intentions of the parties, itmvites subjective interpretations and adds to the risk ofabuse. For these reasons a number of modern authori-ties,150 including the previous Special Rapporteur (A/CN.4/107, paragraph 149) reject the theory of animplied term and formulate the doctrine as an objectiverule of law by which, on grounds of equity and justice,an essential change of circumstances radically affecting

155 Baron de Taube , L'inviolabilite des Traites, Recneildes Cours, 1930, Vol. II, p . 361 .

156 C. Rousseau, op. cit., p . 584; Sir J. Fischer Will iams,A.J.I.L., 1928, pp . 93-94; C. D e Visscher, Theories et Rea-lties en droit international public, p . 391 ; J. Basdevant," Regies generates du Droi t de la Paix ", Recueil des Cours1936, Vol. IV, pp . 653-654; Lord McNair , however, so far ashe admits the doctrine at all, seems to consider it to be basedon an implied condition.

the basis of a treaty will entitle a party to call for itstermination. The Havana Convention on Treaties of1928 157 seems also to state the doctrine in the form ofan objective rule of law; and the present draft has beenprepared upon this basis.9. Many of the authorities (as also article 15 of theHavana Convention) limit the application of the doctrineto " perpetual treaties " and the previous Special Rap-porteur's draft limited it to " treaties not subject to anyprovision, express or implied, as to duration ". In para-graph 159 of his second report (Commentary to hisarticle 21) he said:

" There is a general consensus of opinion that theprinciple rebus is only relevant to the case of whatare sometimes called ' perpetual treaties ' — indeed itcan be said that the principle has no raison d'etre inthe case of other treaties, for it is precisely to remedythe hardship that might result from perpetuation, ifan essential change of the order contemplated by therebus principle occurs, that the principle exists. If thetreaty is not of this kind, either the question doesnot arise, for the treaty can be terminated by othermeans . . . or else the treaty will expire in due courseunder its own terms; and this event can reasonablybe awaited, for, short of supervening literal im-possibility of performance (which would terminatethe treaty in any case), a change of circumstances canhardly be of such a character that termination cannotawait the natural advent of the treaty term. Indeed,it is a legitimate inference, as a matter of interpreta-tion, that, if the parties provided a term, they meantto exclude earlier termination on any basis otherthan further special agreement, fundamental breach,or literal impossibility of performance."

10. The present Special Rapporteur does not find thisreasoning altogether persuasive. When a treaty is for abrief term or is terminable upon notice, the applicationof the doctrine is clearly without any utility. But whena treaty is expressly given a duration of ten, twenty,fifty or ninety-nine years, it cannot be excluded that afundamental change of circumstances may occur whichradically affects the basis of the treaty obligations. Thecataclysmic events of the present century show howradically circumstances may change within a period ofonly ten or twenty years. If the doctrine is put, as itwas put by the previous Special Rapporteur, on thegeneral ground of equity and justice, it is not evidentwhy a distinction should be made between " perpetual "and " long term " treaties. The inference which he drawsas to the intention of the parties to exclude earlier termi-nation is perfectly legitimate, if the doctrine is regardedfrom the point of view of the " implied condition '"theory; but it does not seem to be so, if the doctrine isregarded as an objective rule of law founded uponthe equity and justice of the matter. Moreover, as onemodern text book points out,158 practice does not alto-gether support the view that the doctrine is confined to" perpetual " treaties. Some treaties of limited durationactually contain what are equivalent to rebus sic stan-tibus provisions.1 r'9 The doctrine has also been invoked

157 Article 15; see: Harvard Law School, Research inInternational Law, III, Law of Treaties, p . 1206.

158 C. Rousseau, op. cit., p . 586.159 e.g., art. 21 of the Treaty on Limitat ion of Naval

Armament , signed at Washington, 6 February 1922 (Hudson,


sometimes in regard to limited treaties as, for instance,in the Resolution of the French Chamber of Deputiesof 14 December 1932, expressly invoking the doctrineof rebus sic stantibus with reference to the Franco-American war debts agreement of 1926.1G0 Desirablethough it may be to limit the scope of the doctrineas narrowly as possible, the present Special Rapporteurconsiders that, if the doctrine is accepted as an objectiverule of law, no distinction should be made between" perpetual " and limited treaties. The rule has accord-ingly been framed in the present articles as one ofgeneral application, though for purely practical reasonsit may seldom or never have relevance for treaties oflimited duration or which are terminable upon notice.

11. Paragraph 1 (a), in order to emphasize thenarrow scope of the doctrine, begins with the negativeproposition that a change of circumstances does not,as such, affect the validity of a treaty. Paragraph 1 (b)then formulates the general rule that an essential changein the circumstances forming the basis of the treatymay be considered to affect its validity, and at the sametime expressly limits the application of this principleto cases fulfilling the requirements stated in the furtherparagraphs of the article.

12. Paragraph 2 seeks to define the changes of circum-stances which may give rise to a right to invoke therebus sic stantibus doctrine. Although the basic conceptis clear, a definition that is completely adequate is noteasy to find. Many Common Law judges have similarlytried to formulate the corresponding definition of thechanges of circumstances which justify an appeal to theanalogous doctrine of frustration of contract, withoutfinding any combination of words that satisfied allminds.161 Although the doctrine is properly to beregarded as an objective rule of law, its application inany given case cannot be divorced from the intentionsof the parties at the time of entering into the treaty;for the rationale of the rule is that the change ofcircumstances makes the treaty obligations today some-thing essentially different from the obligations originallyundertaken. The problem is to define the relation whichthe change of circumstances must have to the originalintentions of the parties and the extent to which thatchange must have affected the fulfilment of those inten-tions.

13. The previous Special Rapporteur made an exhaus-tive study of this problem in his second report (para-graphs 150-154, and 169-174), and it is not necessaryto restate all the various considerations here. The defi-nition which he proposed was contained in the followingprovision of article 22, paragraph 2, of his draft:

" (ii) The change must relate to a situation offact, or state of affairs, existing at the time of theconclusion of the treaty, with reference to whichboth the parties contracted, and the continued exis-

International Legislationfor the Limitation of25 March 1936 {Ibid.,regarding the regime20 July 1936 (Leaguep. 229).

160 For the text ofpp. 384-385.

161 See, for example,1919 A.C., p. 457-460;1944 A.C., p. 274-281;Urban District Council,

, vol. II, p. 820); art. 26 of the TreatyNaval Armament, signed at London,

vol. VII, p. 280); and Conventionof the Straits, signed at Montreux,of Nations Treaty Series, vol. 173,

the resolution, see C. Kiss, op. cit.,

Bank Line Ltd, v. Capel and Co.,Denny Mott and Dickson v. Fraser,

; Davis Contractors Ltd. v. Fareham1956 A.C., p. 719 and 727.

tence of which, without essential change, was envi-saged by both of them as a determining factor movingthem jointly to enter into the treaty, or into theparticular obligation to which the changed circum-stances are said to relate." (iii) The change must have the effect either (a)of rendering impossible the realization, or furtherrealization, of the objects and purposes of the treatyitself, or of those to which the particular obligationrelates; or (b) of destroying or completely altering thefoundation of the obligation based on the situation offact or state of affairs referred to in sub-para-graph (ii)."

Paragraph 2 of the present draft incorporates the mainelements of the above provisions, but is worded alittle differently. The criterion laid down in sub-para-graph (ii) of the previous Special Rapporteur's draft" the continued existence of which, without essentialchange, was envisaged by both of them as a determiningfactor moving them jointly to enter into the treaty "seems, perhaps, to be framed in terms which are toosubjective. They come near to reintroducing the fictionof the implied condition and, if literally interpreted,might almost exclude any operation of the rebus sicstantibus doctrine. In the great majority of cases theparties will have given no conscious thought at all tothe circumstance, which has subsequently changed, as" a determining factor " in moving them to conclude thetreaty, but will have simply taken it for granted as partof the then existing international order of things.Accordingly, difficult although it may be to find the rightcombination of words, it seems desirable to try andexpress the criterion in terms of an objective interpreta-tion of the treaty and of the circumstances whichsurrounded its conclusion.

14. The definition in paragraph 2 contains the mainelements. First, the change must relate to a fact orfactual situation which existed at the time when thetreaty was concluded. Secondly, it must appear from theobject and purpose of the treaty and the circumstancessurrounding its conclusion that the parties assumed theexistence and continued existence of that fact or situa-tion to be a necessary foundation of the obligationsaccepted by them. In other words, it must appear froman objective interpretation of the treaty and the circum-stances surrounding its conclusion that the partiescontracted on the assumption that the fact or situationin question was a necessary basis for the operation ofthe treaty. Thirdly, the effect of the change must besuch as either (i) in substance to frustrate the furtherrealization of the object and purpose of the treaty or(ii) to render performance of the treaty obligationssomething essentially different from what was under-taken. The previous Special Rapporteur expressedalternative (ii) in terms of the destruction or alterationof the foundation of the treaty obligations. It is thought,however, that in determining the relation which thechange of circumstances must have to the original treaty,the relevant consideration is rather the nature and extentof the effect upon the performance of the treaty obliga-tions.

15. Paragraph 3 underlines what is already clearlyimplied in paragraph 2, namely, that a subjective changein the views adopted by a State with regard to atreaty can never furnish a basis for invoking the rebus

Law of Treaties 85

sic stantibus doctrine. The reason for underlining thepoint in a separate paragraph is that appeals to therebus sic stantibus doctrine are so often due in practicenot to essential changes of circumstances, but to a changein a State's policy or attitude towards the treaty.16. Paragraph 4 sets out three cases in which, althoughan essential change of circumstances forming the basisof the treaty has occurred, it may not be invoked forthe purpose of denouncing or withdrawing from thetreaty. Sub-paragraph (a) covers the case where theparty invoking the rebus sic stantibus doctrine hasitself been largely responsible for bringing about thechange of circumstances. Sub-paragraph (b) covers thecase where, after the change of circumstances has takenplace and become perceptible, the State invoking it hasnot raised the question of its effect upon the treaty, buthas continued to act as if the treaty was still in force.The previous Special Rapporteur in article 22, para-graph 3 (iii), of his draft put this exception on thebasis that a failure to invoke the change of circum-stances with reasonable promptness raises a presump-tion that the change was not a fundamental one. Thisis very much how the Court dealt with the questionof France's delay in raising the alleged change ofcircumstances in the Free Zones case,182 and how theSwiss Federal Court dealt with a similar question ofdelay in the case of the Canton of Thurgau v. TheCanton of St. Gallen.1G3 In other words, the previousSpecial Rapporteur and the two Courts in the cases justmentioned seem to have regarded an unreasonable delayin invoking the change of circumstances as raising acase of preclusion (estoppel) covered by the generalprovision in article 4 of the present draft. This seemscorrect, and sub-paragraph (b) has therefore been framedin terms bringing cases of undue delay under the excep-tion in that article. Sub-paragraph (c) covers the contin-gency that the parties might themselves have foreseenthe possibility of a particular change of circumstancesand provided for it expressly or impliedly in the treaty;for in that case the treaty would govern the case andthe rebus sic stantibus doctrine could not be invoked toset aside the treaty.17. Paragraph 5 excepts two classes of treaty provi-sion from the rebus sic stantibus doctrine. Sub-para-graph (a) covers a provision actually effecting a transferof territory, boundary settlement, or grant of territorialrights, such as rights of passage. The contention of theSwiss Government in the Free Zones case, that thedoctrine does not apply to provisions establishing terri-torial rights, seems to be correct, as does also thedistinction made by the French Government betweenprovisions establishing territorial rights and provisionsmerely accompanying a transfer of territory.164 Sub-paragraph (a) is therefore limited to actual transfers ofterritory, boundary settlements, or grants of territorialrights. Sub-paragraph (b), however, adds one case wherea stipulation not creating a territorial right but merelyaccompanying transfer of territory is excluded from thedoctrine, namely, the type of stipulation found in Bremenv. Prussia, where it was clear that the restriction uponthe use of the territory as a fishing port had been an

162 P.C.I.J., Series A / B , N o . 46, p . 157.163 Annual Digest of Public International Law Cases,

1927-8, Case N o . 289.164 See paragraph 4 above.

essential condition of Prussia's willingness to transferthe territory.165 The decision of the German court inthat case would seem to have been entirely correct, andsub-paragraph (b) accordingly incorporates the point inthe present article. Sub-paragraph (c) excepts from therule treaties which are constituent instruments of inter-national organizations, since the dissolution of an orga-nization and the withdrawal of a member from it arematters to be settled by the organization itself.18. Paragraph 6 in effect provides that a State may onlyterminate or withdraw from a treaty on the basis of therebus sic stantibus doctrine either by agreement or by fol-lowing a procedure which offers an objecting party thepossibility of some form of independent determination ofthe claim to invoke the doctrine. Although there are cer-tainly examples of purely unilateral denunciation on thisground, the weight of the opinion both amongst juristsand in State practice is strongly in favour of the viewthat unilateral termination or withdrawal without atleast attempting first to secure the agreement of the otherparties is inadmissible. The precise nature of the actionrequired to be taken before termination or withdrawal ispermissible on the ground of a change of circumstancesraises delicate problems, however, that are similar tothose which arise in connexion with certain other groundsof termination and invalidity. It must therefore be leftto be covered in a general provision in article 25 ofsection IV.

SECTION IV—PROCEDURE FOR ANNULLING, DENOUNCING,TERMINATING, WITHDRAWING FROM OR SUSPENDING ATREATY AND THE SEVERANCE OF TREATY PROVISIONS

Article 23 — Authority to annul, denounce, terminate,withdraw from or suspend a treaty

The rules laid down in article 4 of part I with regardto the authority of a representative to negotiate, drawup, authenticate, sign, ratify, accede to, approve oraccept a treaty on behalf of his State shall also apply,mutatis mutandis, to the authority of a representative —

(a) to annul, denounce, terminate, withdraw from orsuspend a treaty; or

(b) to consent to the act of another State annulling,denouncing, terminating, withdrawing from or suspend-ing a treaty.Commentary

The power to annul, terminate, withdraw from orsuspend treaties, no less than the power to concludetreaties, forms part of the treaty-making power of theState. If that power is normally exercised through themedium of a simple notification in writing, it is never-theless important that ither States should be able tosatisfy themselves as to the regularity and binding cha-racter of an instrument of termination, withdrawal orsuspension. The present article accordingly providesthat the rules concerning the authority of representativesto negotiate and enter into treaties on behalf of theirState, which have been provisionally adopted by theCommission in article 4 of part I (A/5209, chapter II)shall also apply, mutatis mutandis, to the authority ofrepresentatives to terminate, withdraw from or suspendtreaties.

165 See paragraph 3 above.


Article 24 — Termination, withdrawal or suspensionunder a right expressed or implied in the treaty

1. Where a treaty expressly provides for a right to ter-minate, withdraw from or suspend it, or where such aright is to be implied in the treaty under article 17,paragraph 3, of this part, a notice to terminate, with-draw from or suspend the treaty, in order to be effective,must —

(a) be in writing and signed by a representative com-petent for that purpose as prescribed in article 23;

(b) comply with any conditions laid down in thetreaty with regard to the circumstances, period of timeor manner in which such notice may be given;

(c) specify the provision of the treaty under whichsuch notice is given or, failing any such provision, in-dicate the ground upon which a right to give such noticeis claimed under article 17, paragraph 3;

(d) specify the date of the notice and the date uponwhich it is to take effect.2. Unless the treaty otherwise provides, any suchnotice must be formally communicated through thediplomatic or other official channel —

(a) in the case of a treaty for which there is no depo-sitary, to every other party to the treaty;

(b) in other cases, to the depositary, which shalltransmit a copy of the notice to every other party to thetreaty.

3. Unless the notice is one that takes effect imme-diately or the treaty otherwise provides, a notice of ter-mination, withdrawal or suspension may be revoked atany time —

(a) before the date specified in the treaty for thenotice to take effect; or

(b) failing any such specific provision, before theexpiry of the period of time prescribed in the treaty or inarticle 17, paragraph 3, of this part for the giving of thenotice.Commentary1. This article concerns the procedure for exercisinga power of termination, withdrawal or suspension con-ferred either by the terms of the treaty or by operationof law under article 17, paragraph 3. The procedural actrequired, as mentioned in the previous Commentary, isa notification in writing. But, if difficulties are to beavoided, it is essential that the notice should be in dueform, emanate from an authority competent for thepurpose, and be regularly communicated to the otherinterested States.2. Paragraph 1 sets out the requirements to be met ingiving notice or termination or withdrawal. Sub-para-graph (a) provides that the notice must be in writing andsigned by an authority competent for the purpose. Sub-paragraph (b) underlines that it must conform to anyconditions laid down in the treaty itself; e.g. the conditionfrequently found in treaties for recurrent periods of yearsthat notice must be given not less than six months beforethe end of one of the periods. Sub-paragraph (c) providesthat the notice should indicate the legal basis uponwhich the State claims to have a right to terminate,withdraw from or suspend the treaty — either an expressprovision or the legal ground for implying such a right.If such an indication may not be strictly necessary inthe case of an express treaty right, it may neverthelessserve to minimise the risk of an irregular notice by focus-

ing attention on the terms of the treaty provision. Inother cases, it seems desirable to insist upon the legalground for implying a right of termination being statedin the notice, since the implication of the right may becontroversial. In general it is thought better, in theinterests of regularity and certainty in treaty relations,to require the legal basis of the notice to be stated inevery case. Again, in the interests of regularity andcertainty, it is thought desirable to require that the dateof the notice and the date when it is considered to takeeffect should be specified in the instrument; and sub-para-graph (d) so provides.

3. Paragraph 2 insists that a notice of termination etc.should be formally communicated to the other partieseither directly or through the depositary. It sometimeshappens that in moments of stress the termination of atreaty or a threat of its termination may be made thesubject of a public statement either in parliament or inthe Press. But it is considered essential that such state-ments, at whatever level they are made, should not beregarded as a sufficient substitute for the formal legal actwhich both diplomatic propriety and the needs of regu-larity and certainty in treaty relations so clearly require.

4. Paragraph 3, following a similar provision in thedraft of the previous Special Rapporteur (A/CN.4/107,article 26, paragraph 9), provides that a notice of ter-mination, withdrawal or suspension may be revoked atany time before it takes effect. This happens either upona specific date indicated in the treaty, e. g. at the end of aparticular " recurrent " period, or by the expiry of aperiod of notice specified in the treaty or in article 17,paragraph 3. The previous Special Rapporteur's draft hada proviso requiring the assent to the revocation of anyother party " which, in consequence of the original notifi-cation of termination or withdrawal, has itself given sucha notification or has otherwise changed its position ".While the idea behind this proviso is clearly sound, itseems doubtful whether the proviso is really necessary;for any other State, which had followed the example ofthe first State in giving notice of termination or with-drawal, would equally have a right to revoke the notice.5. The previous Special Rapporteur's draft also had aprovision (ibid., article 26, paragraph 6) laying downthat, unless the treaty specifically allows it, a notice oftermination or withdrawal may not be made conditional.But, as long as a notice is framed as a firm and unam-biguous notice of termination or withdrawal, there doesnot seem to be great objection to allowing it to beexpressed to be subject to a condition. If it is permissibleto revoke a notice before it becomes effective, it wouldseem equally permissible to revoke it in advance uponthe happening of a particular contingency. Similarly, ifa condition were to be expressed as a condition prece-dent, it might well affect the date upon which the noticecould be said to have been effectively given; but if theintention to give notice and the form of the conditionwere both unambiguous, the existence of the conditionwould hardly seem sufficient to vitiate the notice as anotice.

Article 25 — Annulment, denunciation, termination orsuspension of treaty obligations under a right arising by

operation of law

1. If a party to a treaty claims to have a right to annul,denounce, terminate, withdraw from or suspend a treaty

Law of Treaties 87

under any of the provisions of articles 5 to 9, 11 to 14,or 19 to 22 of the present articles, it shall be boundfirst to give notice of such claim to the other party orparties to the treaty. The said notice must —

(a) be in writing and signed by a representative com-petent for that purpose as prescribed in article 23;

(b) contain a full statement of the grounds uponwhich the claim is based and of the provision of thepresent articles by which it is said to be justified;

(c) specify the precise action proposed to be takenwith respect to the treaty;

(d) specify a reasonable period within which the otherparty is requested to state whether or not it contests theright of the party in question to take the action proposed;provided that, except in cases of special urgency, theperiod mentioned in sub-paragraph (d) shall not be lessthan three months.2. Any such notice must be formally communicatedthrough the diplomatic or other official channel —

(a) in the case of a treaty for which there is no de-positary, to every other party to the treaty;

(b) in other cases, to the depositary, which shall trans-mit a copy of the notice to every other party to thetreaty.3. If no party makes any objection, or if no reply isreceived before the expiry of the period specified in thenotice, the claimant party shall be free to carry out theaction proposed in its previous notice. In that event, itshall address a further communication to the other partyor parties in the manner laid down in paragraph 2, stat-ing that, in accordance with its previous notice, it annulsor, as the case may be, denounces, terminates, with-draws from or suspends the treaty.4. If, however, objection has been raised by any party,the claimant party shall not be free to carry out the actionspecified in the notice referred to in paragraph 1, butmust first —

(a) seek to arrive at an agreement with the otherparty or parties by negotiation;

(b) failing any such agreement, offer to refer thedispute to inquiry, mediation, conciliation, arbitration orjudicial settlement by an impartial tribunal, organ orauthority agreed upon by the States concerned.5. If the other party rejects the offer provided for inparagraph 4 (£>), or fails within a period of three monthsto make any reply to such offer, it shall be considered tohave waived its objection; and paragraph 3 shall thenapply.6. If, on the other hand, the offer provided for inparagraph 4 (b) is accepted, the treaty shall continue inforce, pending the outcome of the mediation, concilia-tion, arbitration or judicial settlement of the dispute;provided always, however, that the performance of theobligations of the treaty may be suspended provision-ally —

(a) by agreement of the parties; or(b) in pursuance of a decision or recommendation of

the tribunal, organ or authority to which the mediation,conciliation, arbitration or judicial settlement of thedispute has been entrusted.7. Where the treaty itself provides that any disputearising out of its interpretation or application shall bereferred to arbitration or to the International Court of

Justice, such provision, to the extent that there may beany conflict, shall prevail over the provisions of thepresent article.Commentary1. Article 25, although essentially concerned withprocedure, is in many ways the key article for all thosecases where a claim is made to set aside or put an endto a treaty on a ground not expressly or impliedly pro-vided for in the treaty. As already emphasized in theCommentary to article 3, some of the grounds for invali-dating or terminating a treaty, although legitimate inthemselves, carry definite risks to the security of treaties,if they may be arbitrarily asserted and acted upon inface of the objections of other parties. These risks areparticularly serious with regard to claims to denouncea treaty on the ground of an alleged breach or on thebasis of the doctrine of rebus sic stantibus, because itis these grounds which offer the largest scope for uni-lateral assertion and subjective judgment of the facts.But the possibility also exists of unilateral and arbitrarydenunciation of a treaty on other grounds, such as error,limited authority of the representative in concluding thetreaty, or impossibility of performance. The only meansof avoiding or reducing these risks is, first, by givingas much precision as possible to the definition of theseveral grounds in sections II and III, secondly, byprocedural provisions limiting the opportunities for ar-bitrary action. However precise the definitions of thesegrounds may be made, the justification of any claim toannul, denounce, etc., a treaty in any particular casewill often turn upon facts, the determination of which iscontroversial. Accordingly, it is upon the proceduralprovisions regulating the exercise of the right to invokethese grounds that the effectiveness of this branch of thelaw of treaties will ultimately depend.

2. If State practice provides instances of claims todenounce treaties unilaterally, it also shows that the: otherparties have normally expressed strong opposition tosuch claims and have insisted that the treaty could notlegally be abrogated without their agreement.166 [n theFree Zones case even the claimant State took the posi-tion that either the agreement of the other party or adecision of a competent tribunal was necessary to bringabout the termination of a treaty on the basis of therebus sic stantibus doctrine. The Havana Convention onTreaties lli7 also provided that, failing the agreement ofthe other party, a State invoking the rebus sic stantibusdoctrine should appeal to arbitration and that the treatywas to remain in force pending the outcome of thearbitration. The Harvard Research Draft, not only in itsarticles on violation of treaty obligations and rebus sicstantibus, but also in those on fraud and mutual error,required the party claiming the termination of the treatyto seek a declaration to that effect from a "competentinternational tribunal or authority V68 It contemplatedthat the claimant party should have the right, at its ownrisk, to suspend performance of its obligations pendingthe decision of the tribunal or authority; but it saidnothing as to what should happen if the other partydeclined to co-operate in obtaining a decision.

166 See the Commentar ies to articles 20 and 22 above.167 Art icle 15; see: Harva rd Law School, Research in

International Law, III, Law of Treaties, p . 1206.168 Ibid., pp. 1126 and 1144.


3. Sir H. Lauterpacht, in the articles of his first reportdealing with essential validity (A/CN.4/63, articles 11to 15) provided for reference to the International Courtof Justice in the case of treaties imposed by force andillegality of object; and for reference to " the Interna-tional Court of Justice or any other tribunal agreed uponby the parties " in cases of disregard of constitutionallimitations, fraud or error. He explained these provisionsin the following comment upon his article concerningerror: *' The principle of compulsory jurisdiction of in-ternational tribunals to determine the existence of erroras a cause of invalidity of a treaty must, upon analysis,be regarded as a principle de lege lata. This is so for thereason that any acknowledgment of the right of a partyto terminate unilaterally a treaty on the ground of error— or, generally, of any other allegation of absence ofreality of consent — would be tantamount to a denial ofthe binding force of the treaty."

4. The previous Special Rapporteur covered the ques-tion in articles 20 (cases of breach) and 23 (cases ofrebus sic stantibus) of his second report (A/CN.4/107)and article 23 (all cases of essential validity) of his thirdreport (A/CN.4/115). Leaving aside a small differencein his treatment of rebus sic stantibus cases,169 his pro-posals may be summarized as follows:

The claimant party must first communicate to theother party or parties a reasoned statement of thealleged ground on which annulment, termination orwithdrawal is claimed. If the claim is rejected or notaccepted within a reasonable period, the claimantparty may " offer to submit the matter to an appro-priate tribunal to be agreed between the parties (or,failing such agreement, to the International Court ofJustice) ". If that offer is not accepted within a rea-sonable period, the claimant party may " declare thesuspension of any further performance of the treaty ";and, if the offer still remains unaccepted after sixmonths, the claimant party may declare the actualinvalidity of the treaty. Should the claimant party notoffer reference to a tribunal, the treaty continues inforce. If, on the other hand, the offer is made andaccepted, it lies with the tribunal to decide what tem-porary measures of suspension or otherwise may betaken pending its decision. Finally, if the treaty itselfprovides for reference of disputes concerning it toarbitration or judicial settlement, the treaty provisionis to apply and, in cases of conflict, to prevail over thegeneral provisions.

When explaining these proposals in the context of thedoctrine of rebus sic stantibus, the previous SpecialRapporteur justified them on the basis that " the mainweight of opinion undoubtedly is that a party whichconsiders that, by reason of an essential change of cir-cumstances, a treaty should be revised or terminated,should begin by addressing a request (or at least a rea-soned statement) to that effect to the other party or par-ties, and that there is no automatic or immediateright of unilateral denunciation (A/CN.4/107, para-graph 155). He further said that to admit a right ofunilateral denunciation would be inconsistent with theDeclaration of London of 1871, which denies the rightof a State to release itself from the provisions of a treaty,or to modify them in any way, except with the consent of

169 xhe rebus sic stantibus draft contemplated only suspen-sion of the treaty, not its termination.

the other contracting parties; and that Declaration heconsidered to be still " part of the corpus of writteninternational public law " (ibid., paragraph 156).

5. There is, perhaps, some element of petitio principiiin the previous Special Rapporteur's contention that toadmit a right of unilateral denunciation would be incon-sistent with the principle that a State may not releaseitself from its treaty obligations or modify them withoutthe consent of the other parties, as there is also in hispredecessor's statement that to do so would be tan-tamount to a denial of the binding force of the treaty.The very question at issue in these cases is whether underthe general law any binding treaty ever existed or whe-ther, if it did come into existence, it has, by operation oflaw, been dissolved and ceased to exist. These are ques-tions which, in principle, precede the application of therule pacta sunt servanda; for, if in either case the correctanswer is that in law no treaty obligation existed atthe time of the denunciation, neither is there any roomfor the application of the rule pacta sunt servanda noris it justifiable in law for the other party to invoke therule. In other words, the objection to admitting a rightof unilateral denunciation is not that unilateral denun-ciation of a treaty, as such, violates the rule pacta suntservanda', it is the risk, evidenced by historical instances,that, unless subject to procedural controls, unjustifiedclaims to annul or denounce treaties on legal groundsmay be asserted and the pacta sunt servanda rule beviolated under the pretence of asserting a legal right.This objection is a very real one, and a strong body ofopinion supports the general position taken by the twoprevious Special Rapporteurs in regard to the need forprocedural controls to regulate recourse to alleged legalgrounds for asserting the invalidity, dissolution or sus-pension of treaties.

6. The question then is as to the nature of the proce-dural requirements upon which it may be legitimate toinsist in framing the present articles. Some authoritiesand some States have almost seemed to maintain thatin all cases annulment, denunciation or withdrawal froma treaty are inadmissible without the consent of the otherparties. This presentation of the matter, understandablealthough it is in the absence of compulsory jurisdiction,subordinates the legal principles governing invalidityand termination of treaties entirely to the rule pacta suntservanda and goes near to depriving them of legal signifi-cance. Sir H. Lauterpacht, as already noted, sought tosolve the problem by making all cases of invaliditysubject either to the compulsory jurisdiction of the Inter-national Court or to compulsory arbitration. This wouldcertainly be the ideal solution and the simplest way ofguaranteeing the effectiveness of the rule pacta sunt ser-vanda. But, having regard to the difficulties which pro-posals for compulsory jurisdiction encountered at theGeneva Conference of 1958 on the Law of the Sea, itdoes not seem possible for the Commission to adopt thissolution.

7. Sir G. Fitzmaurice's draft, without subjecting ques-tions of invalidity or termination generally to compul-sory jurisdiction, sought to make willingness to submitthe matter to the Court or to arbitration a means oftesting the legitimacy of a claim to annul, repudiate,denounce or suspend a treaty. If the claim were disputed,and no offer were made to submit the matter to the Courtor to arbitration, the treaty would continue in force and

Law of Treaties 89

unilateral annulment, repudiation, etc., of the treatywould then be illegitimate and a violation of the rulepacta sunt servanda. On the other hand, if the offerwere made and were either not accepted or met with noresponse, the claimant party would be free to act unilate-rally, first by suspending performance of its obligationsand then, after a further interval of six months, byterminating the treaty. Should the offer be made andaccepted, the matter would pass into the hands of thetribunal, whose decision the claimant party would bebound to await.

8. In this system also there is an element of compul-sion; but it is given expression in the form of a conditionwhich a party to a treaty must comply with before itmay lawfully tear up or suspend the treaty under analleged but contested claim of right. The claimant Stateis not bound to accept compulsory adjudication or arbi-tration of the dispute at the instance of the other party,simply because there is an unresolved difference betweenthem with regard to the treaty. Thus, it cannot be takento Court at the instance of the other party when the latterfinds that the negotiations have reached deadlock. Butit may not lawfully proceed to destroy or suspend thetreaty unilaterally on its own ipse dixit as to the legalmerits of its claim; it must first offer arbitration orjudicial settlement. Article 25 of the present draftadopts the same general system as that proposed by theprevious Special Rapporteur, but modifies it in certainrespects.

9. First, paragraph 4 provides that a claimant partymay offer to refer the dispute to " inquiry ", " media-tion " or " conciliation ", as well as to " arbitration " or" judicial settlement ", and that the authority to whichthe dispute is offered to be referred may be any " impar-tial tribunal, organ or authority agreed upon by theStates concerned ". Since arbitration and judicial settle-ment are not acceptable to all States as a means ofresolving disputes, it seems necessary to widen the rangeboth of the procedures and the organs the use of whichmay be offered by the claimant State. This modification,it may be added, brings the system more into line witharticle 33 of the Charter of the United Nations. It alsoserves to emphasise that the basis of the proceduralprovisions laid down in article 25 is not that of imposinga system of compulsory jurisdiction but of framing aprocedural requirement compliance with which is to bea condition of a lawful denunciation or suspension oftreaty obligations without the consent of the other party.

10. The other main modification of the previous SpecialRapporteur's system is in paragraph 3 of article 25,which contemplates that the claimant State shall be freeto act unilaterally at once, if the other parties either replymaking no objection or make no reply at all within theperiod specified in the notice. The previous SpecialRapporteur prescribed a further waiting period of sixmonths, during which it would be permissible to sus-pend the performance of obligations under the treaty,but not to denounce the treaty. The utility of such aprovision in giving the maximum security against uni-lateral termination of treaties is not doubted. But, ifthe primary object of the procedural requirements is toprovide protection against unilateral denunciation oftreaties, account also has to be taken of the interests ofa party which has legitimate cause to invoke one of thegrounds of invalidity or termination contained in sec-

tion II or III. Accordingly, the present Special Rappor-teur has not thought it right to go beyond requiring theclaimant party to state its case to the other party andto allow a reasonable period for the other party tocomment upon that case. The other party, even if notable immediately to take up a definitive position withregard to the claim, should be able within a reasonableperiod to indicate whether it finds anything to contest inthe claimant's statement of its case. A notice 1:0 thateffect will then set in motion the further procedure ofnegotiation, etc., prescribed in paragraph 4, duringwhich the respondent party can develop its objections tothe claimant's case.11. Paragraph 1 provides that any party claiming toannul, denounce, terminate, withdraw from or suspenda treaty must furnish the other party or parties with afull statement of its case in writing and specify, first, theprecise action which it proposes to take and, secondly, areasonable period within which the other party is to saywhether or not it contests the claimant's right to takethat action. The paragraph also provides that the " rea-sonable period " is not to be less than three months,except in cases of special urgency. Whether threemonths is adequate for the general rule is a matter forthe Commission to consider. On the other hand, it ispossible to imagine some cases, such as a case of a gravebreach of the treaty, where there might be special reasonsfor a shorter period of notice.

12. Paragraph 2 merely provides for the regular com-munication of the notice to the other parties eitherdirectly or through the depositary.13. Paragraph 3, for reasons already explained in para-graph 10 above, lays down that, if other party eitherreplies making no objection or makes no reply at allwithin the period specified, the claimant is to be freeto act upon its previous notice and to annul, denounce,etc., the treaty.14. Paragraph 4 lays down that, if any party conteststhe claimant's right to take the action specified in itsnotice, the claimant must in the first instance seek tosettle the matter by negotiation. The negotiations might,no doubt, end in the acceptance or withdrawal of theclaimant's contention or in an agreement to revisethe treaty. If, however, they end in a deadlock, the pro-cedural check upon unilateral denunciation, already de-scribed in paragraphs 8 and 9 above, comes into play.The claimant party, if it wishes to press its point of viewwith regard to the termination or suspension of thetreaty, cannot proceed unilaterally, but must offer torefer the dispute to " enquiry, mediation, conciliation,arbitration or judicial settlement by an impartial tribunal,organ or authority agreed upon by the States con-cerned ".

15. Paragraph 5 provides that, if the offer is rejectedor no reply is forthcoming from the other party withina period of three months, the check upon unilateralaction is removed and the claimant is free to carry outthe action specified in his original notice.16. Paragraph 6 covers the case where the offer ismade and accepted and provides that the treaty shallremain in force pending the outcome of the mediation,conciliation, arbitration or judicial settlement of thedispute agreed upon by the parties. At the same time itrecognizes the possibility of the performance of theobligations of the treaty being suspended provisionally


either by agreement or under a decision or recommenda-tion of the tribunal or body to whom the dispute hasbeen referred. The Special Rapporteur is not unawarethat difficulties may arise in practice in reaching agree-ment concerning the method of peaceful settlement tobe employed or concerning the nomination of thepersons or body to whom the mediation, conciliationor arbitration of a dispute should be entrusted. But itwould hardly seem appropriate to try to resolve allsuch difficulties in the present article. If the partiesfailed to arrive at any agreement on these matters, thequestion might arise whether one or other of the partieswas applying the procedure of the present article ingood faith.

17. Paragraph 7 merely safeguards the operation of" disputes " clauses in treaties which expressly providefor the reference of disputes either to the InternationalCourt of Justice or to arbitration.

Article 26 — Severance of treaties

1. Unless the treaty itself otherwise provides, a noticeframed under article 24 for the purpose of terminating,withdrawing from or suspending the provisions of atreaty shall apply to the treaty as a whole.

2. Except as provided in paragraphs 3 and 4, andunless the treaty itself otherwise provides, a noticeframed under article 25 for the purpose of annulling,denouncing, terminating, withdrawing from or suspend-ing the provisions of a treaty shall apply to the treatyas a whole.

3. (a) A notice framed under article 25 and invokinga ground which relates exclusively to one part of atreaty shall be limited so as to apply only to such part,if —

(i) the provisions of that part are, in their operation,self-contained and wholly independent of theremainder of the treaty (general provisions and finalclauses excepted); and

(ii) acceptance of that part was not made an expresscondition of the acceptance of other parts either bya term in the treaty itself or during the negotiations.

(b) Subject to paragraph 4, the notice shall apply tothe whole of such part and not be limited to particularprovisions.

4. A notice framed under article 25 and invoking aground relating exclusively to one provision of a treatyshall be limited so as to apply exclusively to thatprovision, if —

(a) the provision in question is, in its operation,wholly independent of the other provisions of the treaty(general provisions and final clauses excepted); and

(b) the provision is one with regard to which it ispermissible to make reservations under article 18, para-graph 1, of part I.

Commentary

1. Most writers have examined the severance of treatyprovisions only in discussing how far a breach of atreaty confers upon the injured party a right to terminatethe treaty. Earlier writers tended to regard the provi-sions of a treaty as indivisible, so that the breach ofany provision would entitle the injured party to termi-

nate the whole treaty.170 Later writers came to distinguishbetween breaches of essential and non-essential condi-tions and to that extent can be said to have recognizedthat treaty provisions are in a certain degree separable.In point of fact, two questions of severance arise inconnexion with cases of breach: (1) the question ofsevering inessential from essential provisions for thepurpose of determining what is a material breach; and(2) the question of the injured party's right to denouncethe whole treaty or only those provisions to whichthe breach relates. In the present draft these questionsare covered in article 20, paragraphs 2, 3 and 4. Ithas, however, to be emphasized that the case of breachis a somewhat special one, since the violation of itsrights under the treaty may entitle the injured party toinvoke the principle inadimplenti non est adimplendumand the doctrine of reprisals. In other words, in casesof breach there may be a right to terminate or suspendonly part of the treaty on grounds which are independentof any general concept of the severance of treaty obliga-tions which may be applicable in other connexions.The problem in cases of breach is not so much whetherthe injured party may be entitled to limit its act ofdenunciation or suspension to parts only of the treaty,but whether, despite the material character of thebreach, the injured party may in any circumstances bebound to limit its act of denunciation or suspension tothose provisions, or to that part, of the treaty to whichthe breach relates. This problem will be consideredbelow.

2. Outside the special case of " breach ", there is thegeneral question whether in invoking other grounds oftermination or of invalidity, a party to a treaty is inany circumstances entitled or bound to limit its claimto the provisions, or to the part, of the treaty to whichthe ground of termination or invalidity itself relates.This question is not dealt with in the reports of theprevious Special Rapporteur, but was made the subjectof an article in the Harvard Research Draft. Thisarticle,171 entitled " Separable Provisions ", stated thatthe provisions of the articles relating to cases ofseverance of diplomatic relations, violation of treatyobligations, rebus sic stantibus and mutual error " maybe applied to a separate provision of a treaty if suchprovision is clearly independent of other provisions inthe treaty ".

3. The existence of a general doctrine of the separa-bility of treaty provisions was thought by the authors ofthe Harvard Research Draft to be supported by anumber of considerations. First, it was noted that in1912 the Institute of International Law in its " Regle-ment concernant les effets de la guerre sur les traites " 172

had accepted the principle of separability in the caseof treaties containing provisions of more than one kind.Then it was emphasized that many multilateral treaties

170 For a useful historical summary, see Harvard LawSchool, Research in International Law, III, Law of Treaties,pp. 1135-1139.

171 Article 30; see Harvard Law School, Research in Inter-national Law, III, Law of Treaties, p . 1134.

172 Article 3; see: L'Institut de droit international, Tableaugeneral des resolutions, 1873-1956, pp. 174-175. Curiouslyenough, the Harvard Research Draft, having cited the viewof the Institute with evident approval, did not itself makeprovision for the principle of separability in its article 35dealing with the effect of war on treaties.

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today contain large numbers of articles dealing with avariety of disconnected subjects and that the provisionsrelating to one subject may be quite independent ofthose relating to another. In such cases, it was urged," one provision may be terminated or suspended withoutnecessarily disturbing the balance of rights and obliga-tions established by the other provisions of the treatyand others to remain in force would produce an inequa-lity with respect to the rights and obligations of thetreaty V 7 3 It was recognized that some multilateraltreaties must be regarded as an indivisible whole becauseto allow some provisions to be terminated or suspendedand others to remain in force would produce an inequa-lity with respect to the rights and obligations of theparties under the treaty. It was not thought possible tolay down any generally applicable criterion for deter-mining the treaties which fall within the class ofindivisible treaties, but disarmament treaties and treatiesof mutual assistance against aggression, alliance andguarantee were given as examples; and treaties in whichthe obligations of the parties differ were also consideredto belong to this class. As to the class of divisibletreaties, it was said that even bilateral treaties, forexample treaties of commerce, may be found whichcontain very diverse provisions, some of which are notnecessarily dependent upon the others. But the mainemphasis was placed on the growing number of volu-minous multilateral treaties, such as the Treaty of Ver-sailles, with its 440 articles, the Sanitary Conventionof 1928, with its 172 articles, and other treaties of thesame character, which not infrequently deal with amultitude of different and often unrelated matters. Itwas also pointed out that in a number of instancesparticular provisions of the peace treaties of the FirstWorld War had been revised or terminated while therest of the treaty continued in force; and that sometreaties, like the Treaty of Neuilly, actually providedfor a power to terminate or suspend particular provi-sions, while leaving the rest of the treaty in force.4. The Harvard Research Draft further relied on thefact that the Permanent Court had recognized that" certain articles or parts of a treaty may be quiteindependent of others either because of their arrange-ment or because of the different subject-matter with whichthey deal ".174 In this connexion it cited pronounce-ments of the Court in the Free Zones case,175 in twoadvisory opinions relating to the International LabourOrganisation m and in the Wimbledon case,177 all ofwhich concerned the interpretation of the Treaty of Ver-sailles. They do not seem to carry the matter much beyonda recognition by the Court that some treaties may dealwith one or more subjects in separate series of provi-sions establishing self-contained regimes for each subject;and that this may affect the way in which the interpreta-tion of the various provisions should be approached.178

Although these pronouncements of the Permanent Court

i : a Ha rva rd Law School, Research in International Law,HI, Law of Treaties, pp . 1138-1139.

174 Harva rd Law School, Research in International Law,III, Law of Treaties, p . 1144.

175 P.C.I.J. Series A / B , N o . 46, p . 140.176 Ibid., Series B, N o . 2, pp . 23 and 25; Series B, N o . 13,

p. 18.177 Ibid., Series A, N o . 1, p . 24.178 See generally Hudson , Permanent Court of Interna-

tional Justice, p . 647.

have also been cited by other authorities 179 as evidenceof a general concept in international law of the separa-bility of treaty provisions, it seems necessary to be carefulnot to read too much into them. The considerationswhich may make it legitimate to interpret particularprovisions of a treaty as a self-contained code of rulesare not necessarily identical with those which may makeit legitimate to annul, terminate or suspend a particularpart, whilst leaving the rest of the treaty in force. Arule which, as in the Harvard Research Draft, wouldallow the severance of any " separate provision of atreaty if such provision is clearly independent of otherprovisions in the treaty " may for that reason be toobroadly stated.

5. The most recent text-book on the law of treaties,1SO

while taking the same general line on the separabilityof treaty provisions, is more cautious in proposing ageneral rule. Thus it rightly insists that in cases wheredenunciation takes place under a power conferred bythe treaty, severance is not permissible unless the treatyexpressly contemplates the separate denunciation ofparticular articles. On the other hand, it supports thedistinction between essential and non-essential provisionsin cases of breach, but does not express a view as tothe conditions under which the injured party may limitits denunciation to parts of the treaty. It further givesfirm support to the principle of severance in determiningthe effect of war on treaties, citing a number of decisionsof municipal courts which distinguish between differentkinds of provisions for this purpose. Finally, withoutformulating a precise rule, it suggests that the principleof the separate treatment of treaty provisions has nowgone so far in international law that the principle ofseverance should be regarded as applicable to cases ofinvalidity, whether original or supervening; and itappears to consider that severance may operate eitherto save a particular provision by eliminating from ita part which is invalid or to prevent the invalidity ofa particular provision from striking down the wholetreaty.

6. Neither the Permanent Court nor the present Courthas made any pronouncement upon the separability oftreaty provisions in the context of essential validity orof termination of treaties. The question was raised,however, in both the Norwegian Loans m and Inter-handel182 cases in connexion with the so-called " auto-matic " reservation to declarations under the optionalclause and was dealt with in the opinions of someindividual judges. The fullest treatment of the matteris that of Judge Lauterpacht in the Norwegian Loans ] R3

case, who admitted the principle of severance in the lawof treaties but declined to apply it to the " automatic "reservation. Having noted that early writers consideredevery single provision of a treaty to be indissolublylinked with each other, he said that this is not themodern view. Having referred to the pronouncementsof the Permanent Court mentioned in paragraph 4 ofthis Commentary, he observed that the Opinion of theInternational Court of Justice in the Reservations to the

179 e.g. Lord McNair , Law of Treaties (1961), chapter 28 ;and see Judge Lauterpacht 's Individual Opinion in the Nor-wegian Loans case, I.C.J. Reports, 1956, at p . 56.

180 Lord McNair , op. cit., chapter 28.181 I.C.J. Reports, 1957, p . 9.™* Ibid., 1959, p. 6.1S3 Ibid., 1957, pp. 55-59.


Genocide Convention case181 also showed that "theremay be reasonable limits to the notion of the indivisi-bility of a treaty and that some of its provisions maynot be of a nature essential to the treaty as a whole ".He then continued: 185

" International practice on the subject is not suffi-ciently abundant to permit a confident attempt atgeneralization and some help may justifiably be soughtin applicable general principles of law as developedin municipal law. That general principle of law is thatit is legitimate — and perhaps obligatory — to severan invalid condition from the rest of the instrumentand to treat the latter as valid provided that, havingregard to the intention of the parties and the natureof the instrument, the condition in question does notconstitute an essential part of the instrument. Utilenon debet per inutile vitiari. The same applies alsoto provisions and reservations relating to the jurisdic-tion of the Court . . . However, I consider thatit is not open to the Court in the present case to severthe invalid condition from the Acceptance as a whole.For the principle of severance applies only to provi-sions and conditions which are not of the essence ofthe undertaking."

He considered that the automatic reservation had beenan essential condition of the State's Acceptance as awhole, and was not therefore severabie from it.7. In the Interhandel case Judge Lauterpacht186

reiterated the above views and in this case JudgeSpender 187 also took the same general position, holdingthat the automatic reservation was not severable fromthe declaration because it was " not a mere term butan essential condition of the United States Acceptance "." The reservation ", he said, " could be described as acritical reservation without which the Declaration ofAcceptance would never have been made." JudgeKlaestad,188 on the other hand, was prepared to applythe principle of separability to the automatic reserva-tion in the particular case. He had formed the viewthat the United States had intended to issue a real andeffective declaration accepting compulsory jurisdiction,even if with far-reaching exceptions. That being so, hewas of the opinion that the circumstance that part ofthe reservation conflicted with the Statute of the Courtdid " not necessarily imply that it is impossible for theCourt to give effect to the other parts of the Declarationof Acceptance which are in conformity with the Statute ".This view was shared by Judge Armand-Ugon. Thelatter, however, also arrived at the conclusion that thereservation had not been a " determining factor " at thetime of the formulation and submission of the UnitedStates declaration, and was only an " accessory stipula-tion ".8. The opinions discussed in the two previous para-graphs related to a question of " essential validity "arising out of the conflict of the automatic reservationwith the Statute of the Court. Although the Judgesconcerned differed as to whether severance should orshould not be applied in the particular instance, theyall started from the basis that treaty provisions are,

i « Ibid., 1951, p. 15.185 Ibid., 1957, pp. 56-57.™« i.e.]. Reports, 1959, pp. 116-117.« ' Ibid., p. 57.«» ibid., pp. 77-78.

in principle, severable in cases of essential validityunder certain conditions. They differed primarily in theirfindings as to whether in the particular case severancewould or would not defeat the original intentions ofthe contracting State in making its Declaration ofAcceptance. Clearly, the opinions of these Judgesprovide strong endorsement of the view that the prin-ciple of separability is applicable to cases of essentialvalidity, and this for the purpose of severing a particularprovision from the rest of the instrument. It is necessary,however, when considering their pronouncements con-cerning the conditions for the application of the prin-ciple, to remember that the case concerned a unilateraldeclaration where the intentions of one party only wereinvolved.

9. One other judicial pronouncement needs to bementioned, that of Judge Lauterpacht in the AdvisoryOpinion on AdmissibiUty of Hearings of Petitioners bythe Committee for South-West Africa. Dealing with thegap created in the regime of the Mandate by the refusalof the Mandatory State to co-operate with the Commis-sion, that Judge emphasized that a Mandate constitutesan international status " transcending a mere contractualrelation ". He then continued: 189

" The unity and the operation of the regime createdby them cannot be allowed to fail because of a break-down or gap which may arise in consequence ofan act of a party or otherwise. Thus viewed, theissue before the Court is potentially of wider importthan the problem which has provided the occasionfor the present Advisory Opinion. It is just becausethe regime established by them constitutes a unitythat, in relation to instruments of this nature, thelaw — the existing law as judicially interpreted —finds means for removing a clog or filling a lacunaor adopting an alternative device in order to preventa standstill of the entire system on account of afailure in any particular link or part. This is unlikethe case of a breach of the provisions of an ordinarytreaty — which breach creates, as a rule, a right forthe injured party to denounce it and to claim damages.It is instructive in this connexion that with regard togeneral texts of a law-making character or thoseproviding for an international regime or administra-tion the principle of separability of their provisionswith a view to ensuring the continuous operation ofthe treaty as a whole has been increasingly recognizedby international practice. The treaty as a whole doesnot terminate as the result of a breach of an individualclause. Neither is it necessarily rendered impotentand inoperative as the result of the action or inactionof one of the parties. It continues in being subject toadaptation to circumstances which have arisen."

The case of " separability " discussed in the abovepronouncement was, of course, a very special one, andthe other Members of the Court adopted a somewhatdifferent approach to the case. Moreover, althoughthe Court's three Opinions concerning the South-WestAfrica Mandate may be said to involve a question ofthe impossibility of performing particular stipulationsof the Mandate, the question has not really been treatedby the Court as one of separating the impossible stipula-tion from the remainder of the Mandate.

Ibid., 1956, p. 23, at pp. 48-9.

Law of Treaties 93

10. The broad conclusions at which the SpecialRapporteur has arrived in the light of the availableevidence are reflected in the provisions of article 26.That the principle of separability applies in somemeasure both to cases of invalidity and to cases oftermination or suspension must, it is thought, beaccepted. Clearly it is undesirable that treaties betweensovereign States should be anulled or brought to anend in their entirety upon grounds of invalidity or oftermination or suspension which relate to quite inessen-tial points in the treaty. There is also much force inthe point made by certain of the authorities that sometreaties, more especially peace treaties, contain whatis really a series of separate treaties combined in thesame instrument. Nor is it to be doubted that in multi-lateral treaties laying down objective norms it may notinfrequently be possible to eliminate certain provisionswithout materially upsetting the balance of the parties'interests under the treaty. On the other hand, theconsensual element in all treaties, whether contractualor law-making, requires that the principle of the separ-ability of treaty provisions should not be applied insuch a way as materially to alter the basis of obligationupon which the consents to the treaty were given. Theproblem, therefore, is to find a solution which will keepthe original basis of the treaty intact but at the sametime prevent the treaty from being brought to nothingbecause of grounds of original or supervening invaliditywhich relate to inessential matters.

11. Paragraph 1 covers the case where a partydenounces or suspends treaty provisions in the exerciseof a power expressly or impliedly contained in thetreaty. If cases can be found where a treaty authorizesdenunciation or suspension of particular provisionsonly, it is very clear that the parties to a treaty cannotbe supposed to have intended to authorize such partialdenunciation or suspension of its provisions unless theyhave done so expressly in the treaty.

12. Paragraph 2 states what is conceived still to bethe primary rule, notwithstanding the wide acceptancetoday of the principle of severability. The presumptionstill is that if any part of a treaty is vitiated either bysome original or by some supervening cause of invalidity,the whole treaty will fall to the ground, unless the partiesagree to continue it in force in a modified form. The rea-son is that, whether the treaty be essentially of a contrac-tual or law-making character, there is a process of giveand take in its conclusion and the elimination of any oneprovision from the treaty alters the basis on which theconsents were given. Accordingly, it is only when theprovision in question can fairly be shown not to havebeen material in inducing the consents to the treaty, ornot to have been a material factor in inducing theconsents to other parts of the treaty, that the primaryrule is displaced in favour of the principle of separ-ability.

13. The next two paragraphs deal with cases whereannulment, termination or suspension is claimed onlegal grounds outside the treaty. Paragraph 3 is designedto cover the case, to which attention has already beendrawn, where there is within the treaty one or moreseries of provisions establishing a separate, self-contained regime for a particular matter or matters. Inother words, the instrument contains within itself whatare really two or more separate treaties linked together

in their negotiation and conclusion and by the generalprovisions and final clauses of the instrument, but inother respects quite independent of each other. Thelogical solution here seems to be to regard each partas a separate treaty for the purpose of applying therules of essential validity and termination laid downin sections II and III, provided always that the partsreally are independent of each other and that thecontracting States did not regard acceptance of one partas an essential condition of the acceptance of the otherpart.

14. Paragraph 4 concerns the type of problem illu-strated by the treatment of the " automatic " reserva-tion by some of the Judges in the Norwegian Loans andlnterhandel cases, which is discussed in paragraphs 6-8above. It seems to the Special Rapporteur that theprinciple of severability ought only to be applied toparticular provisions within comparatively narrowlimits; and that it is inadmissible to permit the principleto be so applied as to alter in any essential point thebasis upon which the consents of the parties were givento the treaty. The drafting of the paragraph takesaccount of the opinions expressed by the various Judgesin the cases before the International Court of Justice.It also seemed appropriate here, as in the definition ofmaterial breach in article 20, to relate the questionof the inessential character of the stipulation to thequestion whether or not it is permissible to make it thesubject of a reservation.

SECTION V — LEGAL EFFECTS OF THE NULLITY,AVOIDANCE OR TERMINATION OF A TREATY

Article 27— Legal effects of the nullityor avoidance of a treaty

1. In the case of a treaty void ab initio, any acts donein reliance upon the void instrument shall have no legalforce of effect, and the States concerned shall berestored as far as possible to their previous positions.

2. In the case of a treaty avoided as from a datesubsequent to its entry into force, the rights and obliga-tions of the parties shall cease to have any force oreffect after that date. Any acts performed and any rightsacquired pursuant to the treaty prior to its avoidanceshall retain their full force and effect, unless —

(a) the parties otherwise agree, or(b) the avoidance of the treaty has been occasioned

by the fraudulent acts of one of the parties, in whichcase it may be required to restore the other party asfar as possible to its previous position.

3. Paragraphs 1 and 2 shall also apply, mutatismutandis where a particular State's consent to a multi-lateral treaty is void ab initio or is avoided upon a datesubsequent to the entry into force of the treaty withrespect to that State.

Commentary1. This article deals only with the legal effects of thenullity or avoidance of a treaty. It does not deal withany questions of responsibility or of redress arising fromacts which are the cause of the nullity or avoidance ofa treaty. Fraud or coercion, for example, clearly raisequestions of responsibility and redress as well as ofnullity or avoidance. But those questions fall outside the


scope of the present part, which is concerned only withthe nullity or avoidance of the treaty.2. Paragraph 1 provides that when a treaty is voidab initio any acts done under it are without any legalforce or effect; and that the States concerned are as faras possible to be restored to their previous positions.It could perhaps be urged that in the case of a treatyvoid ab initio for conflict with a rule of jus cogens, theprivate law principle in pari delicto potior est conditiodefendentis should be applied. But it is believed that arule requiring the parties to be restored as far as possibleto their previous positions would be more suitable fortreaties between States and more conducive to thegeneral international interest.3. Paragraph 2 provides that, in the case of a treatysubsequently avoided as from a particular date, its provi-sions cease to apply after that date, but that acts doneor rights acquired prior to its avoidance remain valid.This is the normal consequence of the avoidance of atreaty which is merely voidable. On the other hand, itwould seem right to provide for a right to restitutio inintegrwn in cases where the ground of the avoidanceof the treaty was the use of fraud by one of the partiesin procuring the other's consent to the treaty.4. Paragraph 3 adds that the same rules apply mutatismutandis, where a particular State's consent to a multi-lateral treaty is void ab initio or is subsequently avoided,without the general validity of the treaty being affected.Such cases are likely to be rare; but if one should occur,it seems logical that it should be governed by the sameprinciples.

Article 28 — Legal effect of the termination of a treaty

1. Unless the treaty otherwise provides or the partiesotherwise agree, the lawful termination of a treaty underany of the provisions of section III —

(a) shall automatically release the parties from anyfurther application of the provisions of the treaty; but

(b) shall not affect the validity of any act performedor of any right acquired under the provisions of thetreaty prior to its termination.2. Paragraph 1 also applies mutatis mutandis in caseswhere a particular State lawfully denounces, or with-draws, from a multilateral treaty.3. The fact that under paragraph 1 or 2 of thisarticle a State has been released from the further execu-tion of the provisions of a treaty shall in no way impairits duty to fulfil any obligations embodied in the treatywhich are binding upon it also under international lawindependently of the treaty.

Commentary1. Article 28, like the previous article, does not dealwith any question of responsibility or redress that mayarise from acts which are the cause of the terminationof a treaty, such as breaches of the treaty by one ofthe parties; it is limited to the legal effects of a treaty'stermination.

2. Paragraph 1 provides that the termination of a treatyreleases the parties from any further execution of thetreaty, but does not affect the validity of acts performedor rights acquired under the treaty prior to its termina-tion. These provisions are, of course, subject to variationeither by the terms of the treaty itself or by agreementof the parties at the time of termination. Article XIXof the Convention on the Liability of Operators ofNuclear Ships,190 for example, expressly provides thateven after the termination of the Convention liabilityfor a nuclear incident is to continue for a certain periodwith respect to ships the operation of which was licensedduring the currency of the Convention.

3. The provisions of paragraph 1 are largely self-evident and their main importance is to underline thatthe termination of a treaty does not in principle haveany retroactive effects on the validity of the acts of theparties during the currency of the treaty nor dissolverights previously acquired under the treaty. The applica-tion of the treaty during the period when it was in forceand the legal consequences flowing therefrom are not inany way affected by the treaty's termination.

4. Paragraph 2 provides that the position of anindividual State which denounces or withdraws froma multilateral treaty is governed by the same principles.Occasionally, a multilateral treaty expressly providesthat the denunciation of the treaty by an individual Statedoes not release it from its obligations with respect toacts done during the currency of the Convention; e.g.the European Convention on Human Rights andFundamental Freedoms m (article 65). But in the greatmajority of cases the treaty is silent upon the pointand simply assumes that the principles contained in thepresent article will apply.

5. Paragraph 3 provides — ex abundanti cautela —that release from the execution of the provisions of atreaty does not affect the liability of the parties toperform obligations embodied in the treaty which arealso binding upon them under general international lawor under another treaty. The point, although self-evident, is perhaps worth including in the draft articles,seeing that a number of major Conventions embodyingrules of general international law and even rules ofjus cogens contain denunciation clauses. A few Conven-tions, such as the Geneva Convention of 1949 for thehumanising of warfare, expressly lay down that denun-ciation does not impair the obligations of the partiesunder general international law. But the majority oftreaties do not, and even the Genocide Convention 192

provides for its own denunciation without indicating thatthe denunciating State will remain bound by its obliga-tions under general international law with respect togenocide.

190 Signed at Brussels on 25 May 1962.191 United Nations Treaty Series, vol. 213, p. 252.!92 Ibid., vol. 78, p. 277.