The Communist International (Comintern), also known as the Third International, was an international organization founded in 1919 that advocated world communism, and which was led and controlled by the Communist Party of the Soviet Union. The Comintern resolved at its Second Congress in 1920 to "struggle by all available means, including armed force, for the overthrow of the international bourgeoisie and the creation of an international soviet republic as a transition stage to the complete abolition of the state". The Comintern was preceded by the dissolution of the Second International in 1916. Vladmir Lenin and Leon Trotsky were both honorary presidents of the Communist International.

The Communist Party of the Soviet Union (CPSU), at some points known as the Russian Communist Party, All-Union Communist Party and Bolshevik Party, and sometimes referred to as the Soviet Communist Party (SCP), was the founding and ruling political party of the Soviet Union. The CPSU was the sole governing party of the Soviet Union until 1990 when the Congress of People's Deputies modified Article 6 of the 1977 Soviet Constitution, which had previously granted the CPSU a monopoly over the political system. The party's main ideology was Marxism–Leninism.