Cold War Timeline

The Cold War pitted the Soviet Union and its communist allies against the United States and its Western allies. From 4 to 11 February 1945, Roosevelt, Churchill and Stalin met at Yalta to plan Germany's defeat and arrange the postwar world. At Potsdam, Truman told Stalin of the new atomic bomb. The United States dropped atomic bombs, the first used in war, on Hiroshima and Nagasaki, on 6 and 9 August 1945. The Soviets blocked the free elections Yalta had promised, and eastern Europe passed under communist rule. Stalin wanted that control as a buffer against a renewed threat from Germany.

George Kennan's 'Long Telegram' set out a policy of 'containment' toward the Soviet Union. Churchill's famous speech declared an 'iron curtain' had fallen across Europe. After Britain announced it could no longer support Greece, Truman presented the Truman Doctrine before Congress on 12 March 1947. Speaking at Harvard on 5 June 1947, Secretary of State George Marshall urged a program for rebuilding Europe. When the Western Allies introduced a new currency in Berlin, the Soviets blockaded the city, cutting it off from the West.

An airlift of supplies kept West Berlin alive until the Soviet Union, on 12 May 1949, lifted the blockade. The blockade and the airlift made Berlin a symbol of the West's resistance to Soviet expansion and communism. In the North Atlantic Treaty, Western nations agreed to treat an armed attack on any member as an attack on all. Not long after the blockade ended, Germany divided into two states: West Germany came first, then East Germany. The first Soviet atomic bomb test ended America's monopoly on the atomic bomb. After victory in China's civil war, Mao Zedong proclaimed the People's Republic of China, and Chiang Kai-shek's Nationalists fled to Taiwan.

North Korea invaded South Korea in 1950, and the United States, with other UN members, committed troops to defend the South. When the US-led forces crossed into North Korea, China sent troops to help the North. The armistice was signed on 27 July 1953, ending the fighting, and Korea stayed divided roughly where the war had begun. In February 1956 Khrushchev condemned Stalin's crimes and his personality cult before the Soviet Communist Party's 20th Congress. The attack on Stalin helped provoke the uprisings against Soviet rule in Poland and Hungary later that year, and Soviet forces invaded Hungary, crushing the revolt.

Sputnik 1 fed American fears that Soviet technology had moved ahead. In 1961 East Germany raised the Berlin Wall against East German flight west. After the US-backed landing at the Bay of Pigs failed, Khrushchev and Castro put Soviet nuclear missiles in Cuba to discourage another attack. On 28 October 1962, Khrushchev consented to withdraw them for a United States pledge not to invade Cuba; sobered, both sides opened a direct Washington-Moscow hotline and pursued nuclear arms treaties.

A treaty signed on 5 August 1963 by the US, the Soviet Union and Britain banned nuclear tests except underground. China's first nuclear test, on 16 October 1964, made it a nuclear power. Mao closed China's schools in the Cultural Revolution and aimed Red Guards at party officials and 'bourgeois' values. Israel beat Egypt, Jordan and Syria in the Six-Day War, seizing Sinai, Gaza, the West Bank, East Jerusalem and the Golan Heights. The Tet Offensive failed militarily yet drained public support in America for the war in Vietnam. After Tet, President Johnson limited bombing of North Vietnam, sought peace talks and announced he would not run again.

Alexander Dubček's Prague Spring pursued 'socialism with a human face', ending censorship and freeing the press. On 1 July 1968, the Soviet Union, the United States, Britain and 59 other states signed the Non-Proliferation Treaty, designed to halt the spread of nuclear weapons. Warsaw Pact forces under Soviet leadership then invaded Czechoslovakia, crushed the reforms and ended the Prague Spring. Moscow justified the move with the Brezhnev Doctrine, claiming a right to step in wherever socialism came under threat. The invasion left China more fearful of the Soviet Union. Richard Nixon, who followed Johnson, took forward the strategic arms limitation talks his predecessor had backed.

On 20 July 1969, Apollo 11 carried the first people to the Moon, a victory for the United States in the space race against the Soviet Union. The rivalry soon eased into détente, which brought more trade and cooperation along with arms control talks. Nixon's better relations with China, including his visit there, drove the Soviet Union to seek détente with the United States. In Moscow on 26 May 1972, Nixon and Brezhnev signed the ABM Treaty along with an interim SALT I agreement that limited strategic arms. On 1 August 1975, the Helsinki Final Act recognized the postwar borders of Europe and supported human rights. Soviet troops then invaded Afghanistan to keep its communist government in power, beginning a long war against the Muslim rebels.

Rivalry between the superpowers in the Third World and the Soviet intervention in Afghanistan weakened détente and brought the Cold War back. On 31 August 1980, Poland's communist government yielded to Gdańsk shipyard strikers, who then created the independent union Solidarity. On 13 December 1981, Jaruzelski declared martial law across Poland to break Solidarity. On 23 March 1983, Reagan put forward the Strategic Defense Initiative, a missile shield partly in space, nicknamed "Star Wars". The early 1980s brought renewed Cold War tension; even with Solidarity's leaders under arrest, the union continued underground.

Mikhail Gorbachev became leader of the Soviet Union on 11 March 1985, after Konstantin Chernenko died. He launched reforms called perestroika, or restructuring, and glasnost, or openness. After meeting at the Reykjavik Summit, Gorbachev and Reagan signed the INF Treaty, scrapping intermediate-range nuclear missiles. On 4 June 1989, China's government violently put down protests in Tiananmen Square. As Gorbachev relaxed Moscow's grip on Eastern Europe, communist rule collapsed across the region. On 9 November 1989, East Germany threw open the Berlin Wall, and East Germans crossed freely to the West.

Gorbachev accepted the reunification of Germany and agreed that the reunited country would join NATO. On 31 July 1991, he and Bush signed START I, the Strategic Arms Reduction Treaty. In August 1991, a coup by Communist hard-liners against Gorbachev failed, and his authority was badly weakened afterward. The reforms he had introduced ended up breaking the Soviet Union apart. He resigned the Soviet presidency, and the state ceased to exist. With that collapse, the Cold War was over.