Détente and Its Collapse 1969–1985

Détente — the relaxation of Cold War tensions — represented the most sustained attempt to manage superpower relations cooperatively. From the late 1960s to the mid-1970s, the United States and the Soviet Union negotiated arms control agreements, expanded trade, and developed rules for their relationship. Yet by the early 1980s, détente had collapsed and the Cold War had intensified to levels not seen since the Cuban Missile Crisis. The key question is: was détente a genuine transformation of the Cold War, or merely a temporary pause driven by mutual convenience?

Key Definition: Détente (French for "relaxation") refers to the easing of strained relations between the USA and USSR, approximately 1969–1979. It encompassed arms control agreements, diplomatic summits, trade expansion, and the Helsinki Accords, but did not end ideological competition or the arms race.

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Why Did Détente Emerge?

Both superpowers had reasons to pursue détente:

American Motivations

Factor	Detail
Vietnam	The war demonstrated the limits and costs of military intervention
Economic pressure	The cost of Vietnam and the arms race strained the US economy
Nuclear parity	The USSR had achieved rough strategic parity by the late 1960s; superiority was no longer achievable
Nixon's realpolitik	Nixon and Kissinger pursued a pragmatic foreign policy based on national interest rather than ideology
Sino-Soviet split	The Sino-Soviet split (openly hostile from 1960, border clashes in 1969) offered the opportunity to play China against the USSR

Soviet Motivations

Factor	Detail
Economic stagnation	The Soviet economy was slowing; Western technology and trade were needed
Nuclear parity	Having achieved parity, the USSR wanted it recognised and stabilised
China	The Sino-Soviet split and border clashes made improved relations with the US desirable
European security	Recognition of post-war borders in Europe, particularly the Oder-Neisse line and the division of Germany

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Nixon, Kissinger, and Triangular Diplomacy

Richard Nixon and his National Security Adviser (later Secretary of State) Henry Kissinger pursued a strategy of triangular diplomacy — exploiting the Sino-Soviet split to gain leverage with both communist powers.

Nixon's Visit to China (February 1972)

Nixon's visit to Beijing (21–28 February 1972) was a diplomatic revolution. The "Shanghai Communiqué" laid the groundwork for normalisation of Sino-American relations (full diplomatic recognition came in 1979 under Carter). The visit shocked Moscow and incentivised Soviet willingness to negotiate.

Moscow Summit (May 1972)

Three months after visiting Beijing, Nixon visited Moscow. The summit produced:

• SALT I (Strategic Arms Limitation Talks) — the Anti-Ballistic Missile (ABM) Treaty and an Interim Agreement limiting ICBMs and SLBMs
• Trade agreements, including a major grain deal
• The Basic Principles Agreement — rules for superpower conduct

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Arms Control Agreements

Agreement	Date	Key Provisions
SALT I — ABM Treaty	May 1972	Limited anti-ballistic missile systems to two sites per side (later one)
SALT I — Interim Agreement	May 1972	Froze ICBM and SLBM numbers at existing levels for five years
Vladivostok Accord	November 1974	Framework for SALT II: equal ceilings of 2,400 delivery vehicles
SALT II	June 1979	Limited each side to 2,250 delivery vehicles; never ratified by the US Senate

Exam Tip: SALT I was significant but limited — it froze numbers but did not reduce them, and it did not limit MIRVs (Multiple Independently-targetable Re-entry Vehicles), which allowed existing missiles to carry multiple warheads. The arms race continued within the framework of arms control.

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The Helsinki Accords (August 1975)