Cold War, a term used for the period of tense relations between the United States and the Soviet Union, stretching from the late 1940s to the late 1980s when Communism collapsed in Eastern Europe and the USSR ceased to exist. The two superpowers faced each other as leaders of conflicting political, economic and ideological alliances; became engaged in a nuclear arms race; and fought surrogate wars with each other in various locations in the Third World, from Korean, to Cuba and to Afghanistan. The two superpowers became rivals through immensely different social ideolo