members of the Chinese Communist Party (CCP) opposed these changes, believing that they would have negative repercussions for the worldwide Communist movement, among whom Stalin was still viewed as a hero. Mao believed that Khrushchev did not adhere to Marxism–Leninism, but was instead a revisionist, altering his policies from basic Marxist–Leninist concepts, something Mao feared would allow capitalists to regain control of the country. Relations between the two governments soured. The USSR refused to support China's case for joining the United Nations and reneged on its pledge to supply China with a nuclear weapon. Mao went on to publicly denounce revisionism in April 1960. Without pointing fingers at the Soviet Union, Mao criticized its ideological ally, the League of Communists of Yugoslavia. In turn, the USSR criticized China's ally the Party of Labour of Albania. In 1963, the CCP began to denounce the Soviet Union openly, publishing nine polemics against its perceived revisionism, with one of them being titled On Khrushchev's Phoney Communism and Historical Lessons for the World, in which Mao charged that Khrushchev was not only a revisionist but also increased the danger of capitalist restoration. Khrushchev's downfall from an internal coup d'état in 1964 also contributed to Mao's fears of his own political vulnerability, mainly because of his declining prestige among his colleagues after the Great Leap Forward. Precursor In 1963, Mao launched the Socialist Education Movement, which is regarded as the precursor of the Cultural Revolution. Mao had set the scene for the Cultural Revolution by "cleansing" powerful officials of questionable loyalty who were based in Beijing. His approach was less than transparent, achieving this purge through newspaper articles, internal meetings, and by skillfully employing his network of political allies. In late 1959, historian and Beijing Deputy Mayor Wu Han published a historical drama entitled Hai Rui Dismissed from Office. In the play, an honest civil servant, Hai Rui, is dismissed by a corrupt emperor. While Mao initially praised the play, in February 1965, he secretly commissioned his wife Jiang Qing and Shanghai propagandist Yao Wenyuan to publish an article criticizing it. Yao boldly alleged that Hai Rui was really an allegory attacking Mao; that is, Mao was the corrupt emperor, and Peng Dehuai was the honest civil servant. Yao's article put Mayor of Beijing Peng Zhen on the defensive. Peng, a powerful official and Wu Han's direct superior, was the head of the "Five Man