Cold War
In 1953, the Soviet leader Joseph Stalin died, and Nikolai Bulganin and Nikita Khrushchev took his place. Khrushchev later took sole control of the Soviet Union. Khrushchev's Secret Speech marked a period of de-Stalinization, and Khrushchev tried to undo many of the things done by Stalin (such as the Gulag prisons and Stalin's cult of personality).