The Cold War was the continuing state of political conflict, military tension, proxy wars, and economic competition existing after World War II (1939–1945), primarily between the Soviet Union and its satellite states, and the powers of the Western world, particularly the United States. Although the primary participants' military forces never officially clashed directly, they expressed the conflict through military coalitions, strategic conventional force deployments, extensive aid to states deemed vulnerable, proxy wars, espionage, propaganda, a nuclear arms race, and economic and technological competitions, such as the Space Race.
Despite being allies against the Axis powers and having the most powerful military forces among peer nations, the USSR on the one side, and the UK, France, China and the USA on the other, disagreed about the configuration of the post-war world while occupying most of Europe. The Soviet Union created the Eastern Bloc with the eastern European countries it occupied, annexing some as Soviet Socialist Republics and maintaining others as satellite states, some of which were later consolidated as the Warsaw Pact (1955–1991). The US and some western European countries established containment of communism as a defensive policy, establishing alliances such as NATO to that end.
Several such countries also coordinated the Marshall Plan, especially in West Germany, which the USSR opposed. Elsewhere, in Latin America and Southeast Asia, the USSR assisted and helped foster communist revolutions, opposed by several Western countries and their regional allies; some they attempted to roll back, with mixed results. Some countries aligned with NATO and the Warsaw Pact, and others formed the Non-Aligned Movement.