Americans like to think of World War II as a “great crusade,” but if it was, the country certainly didn’t seem all that fervent about rushing into it. Think of it: by the usual reckoning, World War II lasted six years, from the invasion of Poland on September 1, 1939, to Japan’s surrender on board the USS Missouri on September 2, 1945. US participation spanned less than four years of that total, a little over half the war. Of seven campaigning seasons, the United States missed the first three and was active only in the final four.
After the US strategic victories at the Battles of the Coral Sea (May 7–8, 1942) and Midway (June 4–7, 1942), the Japanese Imperial Navy was no longer capable of major offensive campaigns, which permitted the Allies to start their own offensive in the Pacific.