SNIE 57/1 -67

Significance of Cambodia to the

Viet~namese Communist War Effort

14 December 1967

~%RELN? 142

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APPROVED E�(

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14 December 1967

SPECIAL ,...,. .

NATIONAL INTELLIGENCE ESTIMATE

NUMBER 57/1-67

Significance oF Cambodia~-

�amese Communist War Effort

�

. Submitted by.. �

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DEPUT~~O~f~ThLLIGENCE .

Concurred in by the

UNITED STATES INTELLIGENCE BOARD

�~4~ indicated overleaf

14 December 1967

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Authenticated:

~j~thCUTIVE

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SECRETA~/~I~

The following intelligence organizations participated in the preparation of

this estimate:

The ~entraI Intelligence Agency and the intelligence organizations of the Departments of State� and Defense, and the NSA.

Concurring:

Dr. R. J. Smith, for the Deputy Director, Cenfral Intelligence

Mr. Thomas 1. Hughes, the Director of Intelligence and Research, Departmentof State

Ii. Gen. Joseph F. Carroll, Director; Defense Intelligence Agency

Gen Marshall S Carter, the Director, National Security Agency

: Abs~aining~

Dr Charles H Reichardt for the Assistant General Manager, Atomic Energy Corn

mission and Mr William 0 Cregor for the Assistant Director, Federal

Bureau of Investigation, the sublect being outside of their jurisdiction

.~ WARNING .

ocument contains classified information affecting the national security, of

i State~

i~within the meaning, of the espionage laws, US Code Title ~8,

Sectlor

It is to be seen only by US person especially indoctrinated and authorized,

to receive information; its security must

be, m?intained in accordance with~ ~]REGU-�LATIONS.

No aØtion is to be taken on onyl which may

be cc~ntained herein, regardless of the advantages to be gained, u such

action� is first approved by the Director of Central Intelligence.

Dd?510fl

1

SIGNIFICANCE OF CAMBODIA TO THE

VIETNAMESE COMMUNIST WAR EFFORT

THE PROBLEM.

To estimate the extent and significance of Vietnamese Communist

use of Cambodian territory in support of the Communist war effort

in South Vietnam.

CONCLUSIONS

A. During the past year, increasing Allied pressure on the Corn

munists� military structure in South Vietnam has caused them to de

ipend more heavily on the use of border areas. They use Cambodian

territory as a sanctuary to evade Allied forces, as a refuge for rest, train

ing, medical care, and in some degree as a route for the infiltration of

personnel and military supplies from North Vietnam. We believe that

~ambodian rice currently provides an important proportion of the

food requirement of the VC/NVA regular forces in South Vietnam.

B. We still have no good evidence that military supplies or equipment are moved through Sihanoukville or other Cambodian ports to

Communist forces in South Vietnam. But the Communists continue to

smuggle small quantities of arms and other military equipment from

Cambodia, some of which probably represents unauthorized diversions

from arms imported by the Cambodian Government for its own forces.

C. If the Communists continue their present strategy, the irn

iportance of Cambodia to their war effort will probably grow in 1968,

particularly as a sanctuary and as a source of rice. Denial of Cam

bodian sanctuary would probably not cause the Communist war effort

~to collapse in the neighboring areas of South Vietnam, but would make

it much harder for the Communists to conduct effective military op~rations in these areas.

2

D. pver the past year, Sihanouk has become more aware of the

extent of Vietnamese Communist use of Cambodia and more apprehensive ov~r US intentions. He has made some small efforts to control

activit~ in the border area but he Jacks the military capability to im

pose effective measures. Sihanouk is likely to move toward more

criticislr of the US for real or imagined violations of Cambodian

sovereignty, hoping to deter the US from carrying the war into Cam

bodian territory and thus avoiding direct involvement in the war.

DISCUSSION�

1. Communist use of Cambodian territory for tactical sanctuary, for base areas,

for infiltration of personnel, and as a source of supply does not appear to have

changed fundamentally over the past year. However, as a consequence of grow

ing pressure on the Communist military structure in South Vietnam, border areas

have become of increasing importance in Communist strategy. Bases straddlingthe Cambodian-South Vietnamese border have facilitated Communist operationsby providing safety for command and communication elements and refuge for

Communist forces.

2. Base Areas.2 Of the major Communist base areas that make use of Cam

bodian territory, the most northerly is in the tn-border region where Laos, Cam

bodia, and South Vietnam meet. The Chu Pong and Sc San bases in western

Pleiku and southern Kontum provinces and the large War Zone C complex in

northern Tay Ninh province also lap over into Cambodia. The Kas Kok base

appears to lie principally in Cambodian territory, near where the Mekong River

crosses into South Vietnam. There are less important base areas along the

borders of the Cambodian province of Svay Rieng and the South Vietnamese

provinces of Quang Due and Kien Giang.

3. The functions of these base areas have remained about the same as last

year. They include facilities for resupply and training prior to major engage

ments, and various medical facilities to treat wounded after combat. Some Com

munist combat regiments, which were subsequently engaged in the battles of

Loc Ninh and Dak To, used Cambodian territory to refit and prepare for these

attacks.

4. Tactical Sanctuary. The Communists continue to use Cambodian territoryas a safe haven after combat, but the pattern varies and depends to a greatextent on the circumstances of the engagements with Allied forces. During a

major US search and destroy operation into War Zone C in early 1967, elements

of COSVN took refuge in adjacent Cambodian territory. On the other hand,we have no evidence as yet that Communist combat elements withdrew into

Cambodia after the Loc Ninh battle this fall.

5. Prior to the battle of Dak To, two elements of the Communist B-3 Front

Headquarters and the NVA First Division moved north from the Chu Pong base

to the tn-border area. At least part of this movement probably took place over

trails on the Cambodian side of the border. During the actual battle the two

elements of the B-3 Front Headquarters remained inside the northeastern tipof Cambodia, apparently directing the fight, and afterwards the First Division

1 SNIE 57-67. ~�Significance of Cambodia to the Vietnamese CommunistS War Effort,� dated

26 January 1967, SECRET, provides a considerable amount of background and detail on

Communist use of Cambodia, most of which is still valid.

See centcrspread map.

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6

Headquarters and the headquarters of at least one of its component regimentsmoved into Cambodian territory for sanctuary.

6. Cbmmunist troops withdrawing into northeastern Cambodia penetrate less

than 10 kilometers. Along the more populous southern half of the border, the

penetrations of Cambodia are shallower, and smaller numbers of Communist

troops are usually involved.

7. Infiltration of Personnel. In general, infiltration trails continuing south

ward from Laos follow the Cambodian-South Vietnamese border as far south

as the Phuoc Long-Binh Long region of South Vietnam. They cross back and

forth a~ross the border in many places and lie less than seven kilometers inside

the border on the Cambodian side. Along the trails are a number of way sta

tions fc~r rest, resupply, and medical attention. We have little evidence on the

actual use of the trails for infiltration during 1967. We do know, however, that

units iljl the B-3 Front and COSVN received replacements this year, and it is

likely that many of these replacements used trails in Cambodia for some portionof theii1 journey south.

8. Routes of Supply. We have observed few improvements on the numerous

supply routes from Cambodia into South Vietnam in the past year. In general,

movem~nt on the roads appears to be about the same as last year while move

ment on the waterways in the northeast appears to have increased somewhat.

The mdin direction of movement on these routes is north and east from Cambodia

into Lr~os and the highlands of South Vietnam, and the supplies moved consist

primarily of food. Some of the military supplies moving southward from Laos

to Conimumst forces in South Vietnam are apparently portered through Cambodia jver a system of trails. But there is still no good evidence that the Com

munists have been using Cambodian roads and waterways for this purpose.

9. Food. Food shipments from Cambodia to the Communist forces in South

Viethath and Laos have continued in 1967 but it is difficult to determine the

quantit!es involved. We believe that the VC/NVA Regular forces and admin

isfraliv~ support troops in South Vietnam require about 180 tons of food per day,of whic~h 15 to 20 percent probably comes from Cambodia either directly or via

Laos. Cambodian food is also shipped northward into Laos to support the in

filtration network there.

10. ~ambodian rice is particularly important for Communist troops operatingout of the tn-border, Se San, and Chu Pong base areas in the rice-deficit highlands. Communist troops in these areas are almost certainly unable to obtain

sufficiei~t rice locally or from the coastal plain. If Cambodian rice were not

available, Communist forces in the tn-border base area probably could be sup

plied b~� shipments of North Vietnamese rice down the Laotian route system.This w~uld substantially increase the daily tonnage of supplies moved and the

movem~nt would be more vulnerable to US aerial interdiction. It would, how

_

-~LIII1

�LIIlever, be exceedingly difficult to move sufficient rice farther south to the Se San

and Chit Pong base areas, and Communist troops there might be forced to relocate.

In the �~Var Zone C complex, loss of Cambodian rice would probably force the

Commu~usts to allocate additional personnel to the task of collecting rice from

nearby areas.

11. Weapons and Ammunition. Because of South Vietnamese controls, it is

unlikelyØ that any sizable amount of arms or ammunition is being smuggled up

the Mekong to Phnom Penh and thence to South Vietnam. There is a greaterchance ~hat such material could be brought in through Sihanoukville or else

where along the coast. But despite occasional reports we still have no goodevidenc~ of such movements. We believe that in time we would have tangibleindicatidns of any continuing substantial shipments of arms and ammunition to

Commuhist forces through Sihanoukville, should such movements occur. The

Commuhists do, however, continue to smuggle small quantities of arms and other

miitary~ equipment from Cambodia, some of which probably represents Un

authori~ed diversions from Communist arms imported by the Cambodian Gov

ernment for its own forces.

12. Chemicals and Other Supplies. Some potassium chlorate and other chem

icals us~ful in the manufacture of explosives continue to reach the Communists

via Ca4bodia. But we have little more information concerning the quantitiesinvolved than we did a year ago. The amount of drugs, communications equipment, ahd other supplies obtained from Cambodia appears to have increased

slightly over the past year probably because increased Allied pressures make

it hard~er to procure them within South Vietnam.

13. Outlook. If the Communists continue their present strategy, the im

portanc~ of Cambodia to their war effort will probably grow in 1968, particu

larly as a sanctuary and as a source of rice. Denial of Cambodian sanctuary

would probably not cause the Communist war effort to collapse in the neighboring area~s of South Vietnam, but would make it much harder for the Communists

to conduct effective military operations in these areas.

14. Si~hanouk�s Position. Over the past year, Sihanouk has become more aware

of the e~tent of Vietnamese Communist use of Cambodia and he has made some

small efforts to curtail it. Nevertheless, we do not believe he is likely to make a

major effort, principally because the Cambodian Armed Forces are just not strong

enough.~ The army totals only 32,000 and less than 9,000 regular troops are sta

tioned in provinces along the entire 700 mile border with South Vietnam. In

the tw~ large northeastern provinces of Cambodia, moreover, there are onlyeight border posts and these are manned by small paramilitary units. Four of

these aide clustered around the junction of Route 19 and the South Vietnamese

border, bust north of the Communist Chu Pong base area. Along this sparsely

manned~ frontier from Kontum to northern Tay Ninh are over 20,000 regularCommunist troops.

~�LII1

F

XI

XI

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I ~IIII1

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~III115. Sihanouk�s basic aim continues to be to avoid involvement in the war.

�e is increasingly apprehensive that the US will carry the war against the Corn

unists into Cambodian territory. Since he cannot keep the Vietnamese Corn

unists from using his territory, Sihanouk is likely to move toward more criticism

the US for real or imagined violations of Cambodian sovereignty, hopingus to deter the US.

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