 The Sino-Albanian split was caused by Albania's rejection of China's "Realpolitik" of Sino–American rapprochement, specifically the 1972 Mao–Nixon meeting which the anti-revisionist Albanian Labor Party perceived as an ideological betrayal of Mao's own Three Worlds Theory that excluded such political rapprochement with the West.To the Albanian Marxist–Leninists, the Chinese dealings with the United States indicated Mao's lessened, practical commitments to ideological orthodoxy and proletarian internationalism.In response to Mao's apparently unorthodox deviations, Enver Hoxha, head of the Albanian Labor Party, theorised anti-revisionist Marxism–Leninism, referred to as Hoxhaism, that retained orthodox Marxism–Leninism when compared to the ideology of the post-Stalin Soviet Union.