Which countries were the main allies during World War II?

The main allies during World War II were the United States, the Soviet Union (often referred to as Russia), and Great Britain. These nations formed a coalition against the Axis powers, which included Germany, Italy, and Japan. The alliance among the US, the Soviet Union, and Great Britain was crucial in coordinating military strategies and resources to combat the threats posed by the Axis powers.

During the war, these allied nations worked together on various fronts, sharing intelligence and engaging in joint military operations. The collaboration was pivotal in significant battles and campaigns, such as the D-Day invasion in Europe and the Pacific theater operations against Japan. This partnership also laid the groundwork for post-war geopolitical alignments and the establishment of the United Nations.

The other options listed consist of nations that either were not part of the main Allied coalition or had different roles. For example, Germany, Italy, and Japan were the principal aggressors of the war. France, Spain, and Portugal were not aligned together as major allies, particularly since Spain remained neutral during WWII. As for China, India, and Australia, while they each played roles during the war, they were not organized as the central allies in the same way that the US, Soviet Union, and Great Britain were.