The Significance of Detente and the End of the Cold War (1975-1990)

The term détente refers to the period of relaxed tensions and improved relations between the Soviet Union and the United States.
This period was marked by the Strategic Arms Limitation Talks (SALT I and SALT II), limiting the production of strategic missiles for delivery of nuclear weapons.
The Helsinki Accords (1975), recognising the borders of Europe as set after WWII, also played a significant role in easing tensions.
Détente effectively helped to stabilise the international system, increasing diplomatic contact and negotiation, but it was controversial domestically in the USA, with criticisms it was too soft on the USSR.

The early tenure of President Ronald Reagan was marked by a return to higher tensions and an arms race, effectively pushing pause on détente.
Reagan Doctrine outlined the American strategy of supporting anti-Communist insurgencies worldwide to overturn Soviet supported governments.
The proposed Strategic Defense Initiative (SDI or ‘Star Wars’) aimed to develop a defence system against nuclear attack, escalating the arms race.

The period saw a renewed approach towards détente with new Soviet leader, Mikhail Gorbachev, who introduced economic and political reforms (glasnost and perestroika).
The Intermediate-Range Nuclear Forces (INF) Treaty (1987) eliminated all nuclear-armed ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometres, marking a major step towards the end of the Cold War.
The fall of the Berlin Wall (1989) signified the collapse of Soviet control in Eastern Europe and marked the symbolic end of the Cold War.
The economic strain of the arms race caused the disintegration of the Soviet Union, offically ending the Cold War in December 1991.