The Pacific Theater:
The War Against Japan,
World War II as it was waged in Europe and Asia was, in many respects, two distinct conflicts. The ideological relationship was clear: the Allied powers were determined to defeat fascism as represented by the Axis Alliance. Clearly, military developments in one theater affected the other. But, on both sides, belligerents acted independently. The Germans and Japanese never coordinated strategy because their national interests dictated otherwise. Germany would have benefited from a Japanese attack on Russia or from a Japanese offensive across India and the Middle East, but Japan's leaders wanted to avoid war with the Soviet Union and believed their national survival necessitated concentrating resources in the Pacific and Southeast Asia.
Among the Allies, only the United States played a major role in both Europe and Asia. Given their preoccupation with the struggle against Germany, Britain contributed little to the war against Japan, and the Soviet Union did not declare war on Japan until August 8, 1945—shortly before the Japanese surrendered. The United States thus assumed responsibility for the Allied war