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 Allied Powers. This conflict involved a global struggle that erupted in 1939 when Germany, led by Adolf Hitler, invaded Poland. Japan expanded its influence in Asia and the Pacific, attacking territories such as Pearl Harbor in 1941, which prompted the United States to formally enter the war. Italy, under Benito Mussolini, was also allied with Germany and fought against the Allies.

These three nations formed the Axis Powers, which were opposed by the Allies, including the United States, the United Kingdom, the Soviet Union, and others. The significance of the conflict against the Axis Powers shaped much of modern history, leading to major geopolitical changes and the establishment of the United Nations.

The other choices reference countries or alliances that either did not constitute the primary adversarial forces in World War II or are not relevant within the context of the main combatants involved in the conflict faced by the United States.