Containment is a strategic policy aimed at preventing the expansion of a hostile power or ideology. It was notably used during the Cold War to limit the influence of Soviet Union communism. The idea was to stop the spread of communism to other countries, particularly in Europe and Asia, through various means, including military alliances and economic support. The policy of containment involved several key actions, such as the establishment of NATO and the implementation of the Marshall Plan. These efforts were designed to strengthen democratic nations and create a buffer against potential aggression, ultimately leading to a balance of power in international relations.