Why did détente end?

Détente is known as a period of cooperation and relaxation, after the cold war had been underway for two decades. It started in 1969 and ended in the late 1970´s-1980. The end of détente was followed by disillusionment for its failure and by the rise of the New Right in the US and the Soviet invasion of Afghanistan.In this essay we will examine the causes that drove détente to an end while focusing on different (International Relations) theories.

Focus on Realism.The basic argument for realists is that détente ended because of it changed balance of power and national interests were more important than cooperation.

Classical realism: Thucydide once stated “ growth of Athenian power and the fear caused in Sparta”, this can be compared to the fear of the Soviet union (both international and domestic), which changed balance of power. The US reaction was the second Cold War (Rejection of SALT II, cut of trade…) which reflects the egoist, self-seeking human nature.

Structural realism: It has a similar approach to Classical realism, with the difference that they focus on the international system (change of balance of power) only and when explaining US reaction they don´t give importance to the human nature.We found two different schools of thought within structural realism:1.Defensive realism: It clearly explains détente itself but it doesn´t give an explanation to the Soviets invasion of Afghanistan, as they state that expansion leads to conflict and that states like to remain in their position.2.Offensive realism: It explains both, the Soviet invasion of Afghanistan, as they defend the maximizing of power, and the US reaction as they defend military force. As Mearsheimer once stated “ every state would like to be the most formidable military power, as it is the only guarantee of survival in this world that can be very dangerous”.

Neo-classical realism: The US felt humiliated after giving so many concessions to the USSR (Vietnam, Iran…), and the rise of the New Right plus the election of Reagan(who was quite harsh on the USSR) who made some structural changes, meant a new foreign policy, which drove détente to an end

Focus on Liberalism.Détente was an opportunity of cooperation and both the US and the USSR decided to take that opportunity as they had mutual interests. But in the end the desire for power was stronger than those interests and therefore USSR invades Afghanistan and the US votes for the New Right and rejects the SALT II as they realize USSR had won a lot from détente.Liberal commercial theory, which defends that material interests are important, fails because USSR would have never risked the end of détente for material gains.

The Liberal idea about how mutual interests equal cooperation fails too, as both USSR and US had mutual interests in the end of the arms race but id did not end in cooperation.

There is an ongoing debate in International Relations, which is the one of Agency against Structure.Personalists are the individuals who made an impact in the politics of the moment, in this context being Reagan because of his charisma and authority, which led to a change in US foreign policy, and Brezhnev, whose health and weakness made it easier for hardliners to take over.Structuralists are the ones who say détente ended because of what was going on in the international structure.

In conclusion, both structure and agency are important; Reagan and the New Right , and the structure of the international system had an impact and shaped the end of détente.After examining different theories it is clear that Neo-classical realist theory is the one who best combines both (structure and agency), as liberalism is weak to explain the end of détente and fails to explain the shift to the second Cold War.