Nikita Sergeyevich Khrushchev (15 April [O.S. 3 April] 1894 – 11 September 1971) was the First Secretary of the Communist Party of the Soviet Union from 1953 to 1964 and chairman of the country's Council of Ministers from 1958 to 1964. During his rule, Khrushchev stunned the communist world with his denunciation of Stalin's crimes, and embarked on a policy of de-Stalinization with his key ally Anastas Mikoyan. He sponsored the early Soviet space program, and enactment of moderate reforms in domestic policy. After some false starts, and a narrowly avoided nuclear war over Cuba, he conducted successful negotiations with the United States to reduce Cold War tensions. In 1964, the Kremlin leadership stripped him of power, replacing him with Leonid Brezhnev as First Secretary and Alexei Kosygin