Who did the United States fight in World War II?

The United States fought against Japan, Germany, and Italy during World War II as part of the larger Allied Powers coalition. When the war began, these three countries formed the Axis Powers, opposing the Allies, which included the United States.

Japan initiated the conflict in the Pacific after the attack on Pearl Harbor in December 1941. Germany, under Adolf Hitler, was a dominant force in Europe, launching extensive campaigns and invasions across the continent. Italy, initially led by Benito Mussolini, was part of the Axis alliance before ultimately switching sides as the war progressed.

This answer is supported by the historical context of the war: the U.S. was fully engaged on multiple fronts, including the Atlantic against Germany and the Pacific against Japan. Italy was also a significant participant, though their involvement shifted after the fall of Mussolini's regime. In contrast, other options, such as France and England, were not adversaries of the United States during this conflict; they were allies in the fight against the Axis Powers.