During the Cold War, what was the primary concern of the United States?

The primary concern of the United States during the Cold War was communism. This era, spanning from the end of World War II until the early 1990s, was characterized by intense rivalry between the United States and the Soviet Union, with the latter promoting a communist ideology that posed a ideological challenge to American values and interests. The U.S. adopted a strategy of containment to prevent the spread of communism globally, which influenced its foreign policies, military interventions, and alliances.

Other options reflect different historical contexts. Fascism was a predominant concern during World War II but became less relevant as the Cold War progressed. Isolationism was more prevalent prior to World War II, and the U.S. was actively engaged in world affairs during the Cold War. Imperialism pertains to colonial expansion and was less about the ideological battle that defined U.S. foreign relations during this period. The focus on communism directly influenced numerous critical U.S. actions, including the Korean War and the Vietnam War, as well as significant domestic measures such as the Red Scare.