Détente and Improved Relations

After the Cuban Missile Crisis, both superpowers recognised the need to reduce the risk of nuclear war. The period from the mid-1960s to the late 1970s saw a gradual easing of tensions known as détente (a French word meaning "relaxation"). This lesson examines the key agreements, summits, and developments that characterised this period.

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What Was Détente?

Détente was not the end of the Cold War — the superpowers remained rivals. Instead, it was a period of reduced tension and increased communication, driven by the recognition that nuclear war was unwinnable and must be avoided.

Feature of Détente	Explanation
Arms control	Agreements to limit the growth of nuclear arsenals
Diplomacy	Regular summits between US and Soviet leaders
Trade	Increased economic cooperation
Cultural exchange	Joint scientific and cultural programmes
Reduced rhetoric	Less aggressive public language

Key Term: Détente — a period of eased tension between the superpowers, primarily from the mid-1960s to the late 1970s. It did not end the Cold War but made it less dangerous.

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Why Did Détente Happen?

Both sides had practical reasons for wanting to reduce tensions.

US Motivations

Reason	Explanation
Vietnam War	The USA was bogged down in Vietnam and could not afford another confrontation
Cost of arms race	Nuclear weapons were enormously expensive
Public opinion	The American public was tired of Cold War confrontation
Cuban Missile Crisis	The near-disaster of 1962 showed the need for better communication

Soviet Motivations

Reason	Explanation
Economic problems	The Soviet economy was struggling to keep up with the arms race
Sino-Soviet split	The USSR's relationship with China had deteriorated sharply; the Soviets wanted to reduce the number of their enemies
Cuban Missile Crisis	Like the USA, the USSR was shaken by how close they had come to nuclear war
Desire for Western technology and trade	Access to Western goods and technology could help the Soviet economy

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Key Agreements and Treaties

The Nuclear Non-Proliferation Treaty (NPT, 1968)

• The USA, USSR, and Britain agreed to prevent the spread of nuclear weapons to other countries.
• Non-nuclear states agreed not to develop nuclear weapons in exchange for access to civilian nuclear technology.
• Significant, but notable absentees included France, China, and Israel.

SALT I — Strategic Arms Limitation Talks (1972)

Feature	Detail
Signed	26 May 1972, Moscow
Signatories	President Nixon (USA) and General Secretary Brezhnev (USSR)
Anti-Ballistic Missile (ABM) Treaty	Both sides limited to two ABM deployment sites each
Interim Agreement	Froze the number of ICBMs and SLBMs at existing levels for five years
Significance	First agreement to limit strategic nuclear weapons; symbolised the spirit of détente

Exam Tip: SALT I did not reduce nuclear weapons — it only froze their numbers. Both sides could still develop new types of weapons and improve existing ones. This is an important limitation to note in exam answers.

The Helsinki Accords (1975)

The Conference on Security and Cooperation in Europe (CSCE) produced the Helsinki Accords, signed by 35 nations including the USA and the USSR.

Basket	Content
Basket 1: Security	Recognition of post-war borders in Europe; respect for sovereignty
Basket 2: Cooperation	Increased economic, scientific, and environmental cooperation between East and West
Basket 3: Human rights	Commitment to respect human rights, including freedom of thought, religion, and movement

The Helsinki Accords were controversial:

• Western critics argued that Basket 1 effectively accepted Soviet control of Eastern Europe.
• Supporters argued that Basket 3 gave dissidents in the Soviet bloc a powerful tool — they could now hold their governments to account for human rights abuses.

SALT II (1979)

Feature	Detail
Signed	18 June 1979, Vienna
Signatories	President Carter (USA) and Brezhnev (USSR)
Agreement	Limited each side to 2,250 missile launchers; limited MIRVs (multiple warheads per missile)
Outcome	The US Senate never ratified SALT II because of the Soviet invasion of Afghanistan in December 1979

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Nixon's Visit to China (1972)

One of the most remarkable diplomatic moves of the Cold War was President Richard Nixon's visit to Communist China in February 1972.

Significance	Explanation
Triangular diplomacy	Nixon exploited the Sino-Soviet split by building relations with China, putting pressure on the USSR
Leverage	The USSR was more willing to negotiate with the USA because it feared a US-China alliance
Symbolism	A US President visiting Mao's China was unthinkable just a few years earlier

Exam Tip: Nixon's visit to China is a great example of how realpolitik (practical politics) overrode ideology during détente. Both the USA and China were willing to set aside their ideological differences for strategic gain.

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Limitations of Détente

Despite the agreements, détente had significant weaknesses.

Limitation	Detail
Arms race continued	Both sides developed new weapons (e.g., MIRVs) not covered by treaties
Proxy wars	The superpowers continued to fight through allies (e.g., in Angola, Ethiopia, and Central America)
Human rights	The USSR largely ignored Basket 3 of the Helsinki Accords
Mutual suspicion	Neither side fully trusted the other
End of détente	The Soviet invasion of Afghanistan (December 1979) effectively ended détente

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Summary

Key Event	Date	Significance
NPT	1968	Limited the spread of nuclear weapons
Nixon visits China	February 1972	Exploited Sino-Soviet split
SALT I	May 1972	First strategic arms limitation agreement
Helsinki Accords	1975	Recognised borders; introduced human rights commitments
SALT II	June 1979	Further arms limits, but never ratified

Détente was a period of genuine progress in US-Soviet relations, but it had clear limits. The arms race continued, proxy wars raged, and the spirit of cooperation was ultimately shattered by the Soviet invasion of Afghanistan in 1979.

Exam Tip: For a "How successful was détente?" question, weigh the genuine achievements (SALT I, Helsinki, reduced risk of nuclear war) against the limitations (continued arms race, proxy wars, Soviet invasion of Afghanistan). A balanced answer that reaches a clear judgement will score highest.

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Extended Worked Paragraph: Evaluating Détente