Anti-communism is political and ideological opposition to communist beliefs, groups, and individuals. Organized anti-communism developed after the 1917 October Revolution in Russia, and it reached global dimensions during the Cold War, when the United States and the Soviet Union engaged in an intense rivalry. Anti-communism has been expressed by several religious groups, and in art and literature. Anti-communism has been an element of many movements and different political positions across the political spectrum, including anarchism, centrism, conservatism, fascism, liberalism, nationalism, social democracy, socialism, leftism, and libertarianism, as well as broad movements resisting communist governance.
The first organization which was specifically dedicated to opposing communism was the Russian White movement, which fought in the Russian Civil War starting in 1918 against the recently established Bolshevik government. The White movement was militarily supported by several allied foreign governments which represented the first instance of anti-communism as a government policy. Nevertheless, the Red Army defeated the White movement and the Soviet Union was created in 1922. During the existence of the Soviet Union, anti-communism became an important feature of many different political movements and governments across the world.