133 2. After World War II, the United States and the Soviet Union emerged as superpowers. They each created military alliances made up of nations they protected or occupied. THE UNITED STATES HELPED FORM THE NORTH ATLANTIC TREATY ORGANIZATION (NATO), WHICH COMPRISED WESTERN EUROPEAN ALLIES. The Soviet Union signed the Warsaw Pact with Eastern European countries. The line between the democratic West and communist East was called the Iron Curtain. Many revolts challenging Soviet domination were extinguished with military force.
The superpowers also engaged in a weapons race-both developed nuclear weapons. To reduce the threat of war, the two sides held several disarmament talks. One agreement was intended to limit the use of anti-ballistic missiles (ABMs). These weapons were designed to shoot down missiles launched by hostile nations. The ABMs were considered a threat because they could give one side more protection, which might encourage it to attack. Then during the 1980s, President Ronald Reagan proposed a missile defense program called "Star Wars." Other agreement limited the number of nuclear weapons that nations could maintain, which eased Cold War tensions. This period was called the era of detente. It ended, however, when the Soviet Union invaded Afghanistan in 1979.
During the 1950s, Fidel Castro led a revolution in Cuba and be came its leader. To bring Castro's communist regime, U.S. President John F. Kennedy supported an invasion of Cuba, but the attempt failed. One year later, the Soviet sent nuclear missiles to Cuba. Many feared a nuclear war. After the United States blockaded Cuba, Soviet leader Nikita Khrushchev agreed to remove the missiles.
The Soviet wanted to spread communist ideology around the globe. When Khrushchev came to power, he eased censorship and increased tolerance. However, repression returned under Leonid Brezhnev. American leaders followed a policy of containment. This was a strategy of keeping communism from spreading to other nations. In addition, a "red scare" in the United States resulted in Senator Joseph McCarthy leading an internal hunt for communists in the government and military. The House Un-American Activities Committee (HUAC) also sought out communist sympathizers.
2. What ended the period of detente between the United States and the Soviet Union?