A post-war or postwar period is the interval immediately following the end of a war. The term usually refers to a varying period of time after World War II, which ended in 1945. A post-war period can become an interwar period or interbellum, when a war between the same parties resumes at a later date. By contrast, a post-war period marks the cessation of armed conflict entirely.

The Cold War was a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc, that started in 1947, two years after the end of World War II and lasted to 1991, the fall of the Soviet Union.