What was the primary concern of the United States during the Cold War?

The primary concern of the United States during the Cold War was communism. This period, which lasted roughly from the end of World War II in the late 1940s to the early 1990s, featured intense geopolitical tension between the U.S. and the Soviet Union, which was the leading communist power at the time. The U.S. viewed the spread of communism as a direct threat to democracy and capitalism, leading to various tactics aimed at containment, such as forming alliances (e.g., NATO), engaging in conflict (e.g., the Korean War and the Vietnam War), and participating in various international organizations in opposition to communist influence.

In contrast, while fascism was a concern during World War II, it was not the central issue during the Cold War era. Similarly, isolationism, which refers to a policy of non-involvement in international affairs, was largely abandoned by the U.S. following WWII as it sought to counter the spread of communism globally. Militarism, while present in terms of military build-up and arms races (such as the nuclear arms race), was a response to the communist threat rather than a primary concern in itself. Understanding communism's role in shaping U.S. foreign policy during this