Marxism–Leninism is a political philosophy or worldview founded on ideas of Marxism and Leninism, and seeks to establish socialist states and develop them further. Marxist–Leninists espouse a wide array of views depending on their understanding of Marxism and Leninism, but generally they support the idea of a vanguard party, one-party state, state-dominance over the economy, internationalism, opposition to bourgeois democracy, and opposition to capitalism. It remains the official ideology of the ruling parties of China, Cuba, Laos, Vietnam, and Kerala, and was the official ideology of the Communist Party of the Soviet Union (CPSU) and the other ruling parties making up the Eastern Bloc.
Marxism–Leninism first became a distinct philosophical movement in the Soviet Union during the 1920s, when Joseph Stalin and his supporters gained control of the Russian Communist Party (bolsheviks). It rejected the notions, common among Marxists at the time, of world revolution as a prerequisite for building socialism in Russia (in favor of the concept of Socialism in One Country), and of a gradual transition from capitalism to socialism (signified by the introduction of the First Five-Year Plan). The internationalism of Marxism–Leninism was expressed in supporting revolutions in foreign countries (e.g., initially through the Communist International or through the concept of "socialist-leaning countries" of late Soviet Union).