The Sino-Soviet split (1956–1966) was the breaking of political relations between the People's Republic of China (PRC) and the Union of Soviet Socialist Republics (USSR), caused by doctrinal divergences that arose from their different interpretations and practical applications of Marxism–Leninism, as influenced by their respective geopolitics during the Cold War (1947–1991). 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 world. Against that political background, the international relations of the PRC featured official belligerence towards the West, and an initial, public rejection of the Soviet Union's policy of peaceful coexistence between the Eastern and Western blocs, which Mao Zedong said was Marxist revisionism by the Russian Communists.