The role of the United States in the Cold War was characterized primarily by its opposition to the spread of communism. Following World War II, the U.S. adopted a policy of containment, aiming to prevent Soviet expansion through political, military, and economic means. This involved forming alliances, such as NATO, and engaging in conflicts like the Korean War and Vietnam War to counter communist influence. The U.S. also invested in nuclear arms and propaganda efforts. This complex geopolitical struggle eventually shaped international relations and domestic policies that persist even after the Cold War's conclusion.