The document summarizes key communist world leaders from the 20th century including Nikita Khrushchev, the first secretary of the Soviet Union after Stalin's death who initiated the Cuban Missile Crisis; Fidel Castro, the revolutionary leader and prime minister of Cuba who initially received US support before aligning with communism; Mao Zedong, the ruler of China who established the communist party and launched economic campaigns; and Mikhail Gorbachev, the last Soviet leader who presided over the dissolution of the Soviet Union in 1991.