From 1947 to 1991, the United States and the Soviet Union were locked in a conflict that did not lead to actual major fighting between their militaries—this is why the conflict is often called the “Cold War.” The threat of both sides using nuclear bombs, which would seriously if not catastrophically damage societies and the environment, was a key characteristic of the Cold War. Still, the Cold War did see military conflict in the form of proxy wars between nations supported by both sides, such as the Vietnam War. Although there were periods when the Cold War became less tense, it did not truly end until the dissolution of the Soviet Union in December 1991.

Communism is a political and economic strain of thought within socialism, established by the German philosopher Karl Marx in the 19th century. Interpretations vary even between Communists themselves and there are different schools of Communism. Still, Communism can be defined as a radical form of Socialism. It seeks to have a centralized government that controls both the production and distribution of goods such as food, clothing, and so on. This is in contrast to capitalism, where production and distribution is mainly managed by private for-profit groups, or most other forms of socialism, where only production is partially or entirely regulated and managed by a government.