Détente in the Cold War and diplomacy in the shadow of nuclear annihilation

By the late 1960s, both the United States and the Soviet Union had compelling reasons to reduce tensions.

The Cuban Missile Crisis of October 1962 had brought the world terrifyingly close to nuclear war, and since that confrontation had nearly ended in catastrophe, both governments recognised that unregulated competition carried unacceptable risks.

The direct communications hotline that was installed between Washington and Moscow in August 1963 was colloquially known as the “red telephone” and was an early acknowledgement of that reality (though the system originally operated through secure teletype messages rather than a voice line).

That same effort to reduce nuclear danger also appeared in the 1968 Nuclear Non-Proliferation Treaty, which attempted to prevent the spread of nuclear weapons to additional states.

Equally significant was the economic strain of the arms race. The United States was pouring enormous resources into the Vietnam War, which cost many billions of dollars and placed heavy pressure on American finances.

The Soviet economy, for its part, struggled to produce adequate consumer goods under its Five-Year Plans and had suffered from slowing growth during the 1970s.

Additionally, the Sino-Soviet split had fractured the communist world, and border clashes along the Ussuri River in 1969, especially around Damansky Island, which China called Zhenbao Island, meant that Moscow now faced a potential adversary on its eastern flank.

Nixon and his National Security Adviser, Henry Kissinger, exploited this dynamic through triangular diplomacy and leveraged the tension between China and the Soviet Union to extract concessions from both.

Kissinger’s secret trip to Beijing in July 1971 was followed by Nixon’s visit to China in February 1972, and together these visits gave Washington greater diplomatic flexibility in its dealings with Moscow.

As the centrepiece of détente, arms control negotiations produced several landmark agreements.

The SALT I treaty consisted of two main components: the Anti-Ballistic Missile (ABM) Treaty, which restricted each superpower to only two missile defence sites, one around the national capital and one around an intercontinental ballistic missile field, and the Interim Agreement, which froze the number of intercontinental ballistic missile launchers at existing levels for five years.

The logic of the ABM Treaty held that if neither side could defend itself against a nuclear strike, neither would be tempted to launch one.

In 1974, a further protocol reduced the permitted number of ABM sites from two to one for each side, which tightened these limitations even more.

In practical terms, SALT I contained significant gaps, since it did not cover multiple independently targetable re-entry vehicles (MIRVs), a technology that allowed a single missile to carry several warheads at different targets.

The Interim Agreement also preserved an existing strategic imbalance, since the Soviet Union retained a larger number of land-based ICBM launchers and the United States held important advantages in submarine-launched ballistic missiles along with MIRV technology.

Negotiations for SALT II continued through the Ford and Carter presidencies, and Carter and Brezhnev finally signed the agreement in Vienna in June 1979.

SALT II set a ceiling of 2,400 strategic nuclear delivery vehicles for each side, with a later reduction to 2,250 planned under its terms.

The treaty never received Senate ratification, however, because the Soviet invasion of Afghanistan in December 1979 destroyed the political will needed to push it through Congress.

One of détente’s most consequential dimensions unfolded through Ostpolitik, which was pursued by West German Chancellor Willy Brandt from 1969.

Inspired by his adviser Egon Bahr’s concept of “Wandel durch Annäherung” (change through rapprochement),

Brandt believed that normalising relations with Eastern Europe would foster gradual liberalisation behind the Iron Curtain.

In August 1970, he signed the Treaty of Moscow, which renounced the use of force and accepted existing European borders, and later that year the Treaty of Warsaw formally recognised Germany’s post-war territorial losses east of the Oder-Neisse Line.

In December 1970, Brandt also performed his famous Kniefall von Warschau and knelt at the Warsaw Ghetto memorial in a gesture that became one of the most powerful symbols of post-war German reconciliation.

Perhaps the most important outcome was the Basic Treaty of 1972, which regularised relations between West Germany (officially the Federal Republic of Germany), and East Germany (officially the German Democratic Republic), for the first time since partition and which led to the exchange of permanent missions.

Under its terms, both states accepted each other’s territorial integrity and committed to developing neighbourly relations on the basis of equality, which allowed both countries to join the United Nations in 1973.

Brandt received the Nobel Peace Prize in 1971 for his efforts, and his Ostpolitik created a European framework that complemented the superpower negotiations that were taking place between Washington and Moscow.

On 1 August 1975, thirty-five nations signed the Helsinki Final Act at the Conference on Security and Co-operation in Europe.

The agreement was organised into thematic “baskets” that covered European security and economic cooperation, as well as human rights.

For Brezhnev, the Accords appeared to be a triumph, since Basket I confirmed the inviolability of post-war borders in Eastern Europe, a goal that the Soviet Union had pursued since the 1950s.

In an outcome that few anticipated, Basket III proved far more consequential.

Because the Soviet Union had formally committed itself to respecting human rights and the free flow of information, dissident movements now possessed a powerful tool with which to challenge their governments.

By 1976, activists in Moscow had formed the Moscow Helsinki Group to monitor Soviet compliance, and similar organisations appeared across the Eastern Bloc, including Charter 77 in Czechoslovakia and KOR in Poland.

Daniel Fried, who is a former American diplomat and commentator on the region, has argued that the Helsinki process became synonymous with human rights activism behind the Iron Curtain and contributed to the trends that ended communist rule by 1989.

Several factors contributed to the unravelling of détente in the late 1970s, and proxy conflicts between rival client states, which had continued throughout the period, proved particularly damaging.

The 1973 Yom Kippur War was one notable example, since the United States raised its nuclear alert status to DEFCON 3 on 25 October 1973 in response to fears of Soviet intervention.

Such episodes demonstrated that détente had arguably redirected superpower competition away from direct confrontation rather than eliminating it entirely, and (as mentioned above) the event that definitively ended the period was the Soviet invasion of Afghanistan in December 1979.

President Carter responded by withdrawing SALT II from Senate consideration, imposing a grain embargo, leading a boycott of the 1980 Moscow Olympics, and announcing the Carter Doctrine in January 1980, which declared that the United States would use force if necessary to defend its interests in the Persian Gulf.

Ronald Reagan’s election in 1980 was built on an explicitly anti-détente platform and ushered in what many historians call the Second Cold War.

In assessing the period, the scholar Galen Jackson has challenged the conventional view that Soviet aggression alone destroyed détente and has argued that American actions in the Middle East contributed significantly to its failure.

Whatever the causes of its collapse, détente’s most unexpected achievement may have been the Helsinki Accords, which were an agreement that had been designed to preserve the status quo but that inadvertently planted the seeds of revolutionary change across Eastern Europe.

The later rise of Solidarity in Poland in 1980 offered one of the clearest examples of how human rights language and organised dissent could erode communist authority from within.