Nuclear proliferation

Nuclear proliferation is the increase in the amount of nuclear weapons a country has, or the spread of nuclear capabilities to non-nuclear countries.

Mao Zedong
Chairmain Mao

The superpowers feared nuclear weaponry could fall into the hands of ‘rogue’ governments or terrorist groups. This would have disastrous results for all.

Each side saw themselves as ‘responsible’. But if more countries had nuclear capability, the superpowers would have less power to control events.

The impact of China

The USSR and China had major political disagreements despite both sides being communist.

Khrushchev and Mao had different views on how a communist country should be governed. Khrushchev was determined to wipe out hardliner Stalinist policies, while Mao adopted many of them.

The USA and USSR agreed a policy of Peaceful Co-Existence. This frustrated Mao. He believed the USSR should be doing more to spread communism.

China became a much more serious threat to both sides when it successfully created its first atomic bomb in 1964.


In the late 1960s European countries took a role in promoting the idea of détente. West Germany under Willy Brandt developed Ostpolitik (Eastern Policy). This encouraged greater cooperation and communication through the Iron Curtain. Ostpolitik led to warmer relations between many Eastern and Western countries.

There was a great deal of cooperation and good will between the superpowers during the period of détente.

1972President Nixon visited MoscowNixon met Soviet leader Leonid Brezhnev. The first time a US President had been in the USSR since 1945.
1973Brezhnev visited WashingtonThis emphasised the commitment to work together.
1974President Nixon visited MoscowThis showed continued commitment.
1975Apollo-Soyuz Test ProjectJoint space flight by Soviet and American astronauts.
1970sIncrease in tradeThe Soviet economy was in trouble and had to accept grain shipments from the USA.

A number of political agreements were made during the détente period.

1963Nuclear Test Ban TreatySigned by the USSR, USA and UK. This banned the testing of nuclear weapons on the ground and in the atmosphere but not underground.
1967Outer-Space TreatySigned by the USSR, USA and UK. Banned the placement and testing of nuclear weapons in space and on the moon.
1968Nuclear Non-Proliferation TreatyAn agreement to stop or limit the spread of nuclear capability to non-nuclear countries. The five recognised nuclear countries were USA, USSR, UK, China and France.
1971Seabed TreatySigned by the USSR, USA and UK. Banned the placement of nuclear weapons anywhere on the seabed.
1972SALT ISigned by Nixon and Brezhnev in 1972. The first superpower agreement which put limits on nuclear missile numbers. However, proliferation continued as the limits were so high.
1975Helsinki AgreementThree ‘baskets’ of agreements. Both sides agreed to recognise the current borders of European countries, respect human rights and freedoms in their respective countries and help each other economically and technologically.
1979SALT IIThere was agreement over limiting the production of long-range missiles. However, the Soviet Union invaded Afghanistan in 1979 and the Cold War began to heat up once more.
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