WARNING: This video contains archival footage depicting violence and death. Teacher discretion is advised. For 13 days during the Cuban Missile Crisis in 1962, the world faced the threat of a nuclear holocaust. A year later the Sino-Soviet Split reached it's lowest ebb, and the Vietnam War escalated after the Gulf of Tonkin Incident. Political and military tension diminished in the late 1960s, during the period of détente which lasted until 1979. Disarmament agreements were signed by the superpowers, but flash points threatened to destabilise any move towards a stability. The Red Army's intervention in Czechoslovakia during the Prague Spring of 1968, demonstrated that the Soviets were going to keep Eastern Europe firmly under control. The Yom Kippur War of 1973 in the Middle East saw the USA and the Soviet Union again supporting opposing nations at war. The Soviet invasion of Afghanistan in 1979 signalled the end of détente. Ronald Reagan was elected as the president of America in 1981, and his attitude and policies were extremely anti-Soviet. However, upon forming a friendly relationship with Mikhail Gorbachev, his attitude, and US-Soviet relations improved dramatically. A change swept through Eastern Europe, and in 1989 communism collapsed. The Soviet Union disintegrated in 1991 into fifteen independent republics. The Cold War was finally over.