The Cold War was a state of political and military tension between the Western bloc, led by the United States, and the Eastern bloc, led by the Soviet Union, that lasted from the end of World War II in 1945 until the collapse of the Soviet Union in 1991. The two sides never engaged in direct military conflict, but instead relied on economic, political, and military strategies to compete for global influence. The Cold War was characterized by a buildup of arms, the spread of communism, and the fear of nuclear war. It also had a profound impact on international relations, shaping the global balance of power and the development of new technologies and military strategies.
Source: Gaddis, J. L. (1997). We Now Know: Rethinking Cold War History. Oxford University Press.