Nikita Sergeyevich Khrushchev was first secretary of the Communist Party and de facto leader of the Soviet Union between 1953 and 1964; he concurrently served as premier from 1958 to 1964. Some expert reckon Khrushchev was a reformer: He abolished the most ruthless aspects of the political system and removed the personality cult of Stalin. He tried with limited success to catch up with and overtake the U.S. economy. In foreign affairs, he forcefully maintained the unity of the Eastern bloc and veered between "peaceful coexistence" and several dangerous confrontations with the United States. He was undoubtedly one of the most important figures of the cold war.