In the late 1950s and early 1960s, Sino-Soviet debates about the interpretation of orthodox Marxism became specific disputes about the Soviet Union's policies of national de-Stalinization and international peaceful coexistence with the Western Bloc, which Chinese founding father Mao Zedong decried as revisionism. Against that ideological background, China took a belligerent stance towards the Western world, and publicly rejected the Soviet Union's policy of peaceful coexistence between the Western Bloc and Eastern Bloc. In addition, Beijing resented the Soviet Union's growing ties with India due to factors such as the Sino-Indian border dispute, and Moscow feared that Mao was too nonchalant about the horrors of nuclear warfare.

In 1956, CPSU first secretary Nikita Khrushchev denounced Josef Stalin and Stalinism in the speech On the Cult of Personality and its Consequences and began the de-Stalinization of the USSR. Mao and the Chinese leadership were appalled as the PRC and the USSR progressively diverged in their interpretations and applications of Leninist theory. By 1961, their intractable ideological differences provoked the PRC's formal denunciation of Soviet communism as the work of "revisionist traitors" in the USSR. The PRC also declared the Soviet Union social imperialist. For Eastern Bloc countries, the Sino-Soviet split was a question of who would lead the revolution for world communism, and to whom (China or the USSR) the vanguard parties of the world would turn for political advice, financial aid, and military assistance. In that vein, both countries competed for the leadership of world communism through the vanguard parties native to the countries in their spheres of influence.

By the 1960s, the relationship between Russia and China had only intensified the tensions about which country had control over the lands on their borders. China felt that the Soviet Union had gained these lands through underhanded treaties, while the leaders of the Soviet Union felt that the treaties were legitimate and should be honored. During 1963 and 1964, the Chinese government started to openly challenge their former communist ally for those areas culminating in the Sino-Soviet Border Conflict. Since both countries were nuclear powers, it further intensified the potential dangers both countries posed.