The other invasion also began on June 6, 1944. By virtue of the International Date Line, the two invasions sailed on different days, but both sortied within the same 24-hour period. One invasion involved 127,000 U.S. soldiers and Marines and 535 ships and landing craft. The second invasion had 10 times that number.
One invasion was headed for Normandy in France. The “other” invasion was headed farther, a 10-day voyage from Hawaii and other bases to Saipan, an island 1,200 nautical miles from Tokyo, 12 miles long and 46.5 square miles in area. Once taken, it would provide the U.S. Army Air Forces with a base for the huge Boeing B-29 Superfortress bombers to pound Tokyo. Also up for invasion in the same attack were Saipan’s neighbors, Tinian, and a small piece of American soil that had been violated since Pearl Harbor, the island of Guam, under Japanese occupation for three long years.
Seizing the Northern Marianas would thus redeem American honor. It would also signal to Japan that the Empire’s main defense line had been breached and force the Combined Fleet to emerge from two years of hibernation and training to fight the decisive battle against the Americans to save that Empire—the biggest carrier battle yet fought and one of the most decisive naval battles in history.
A New Generation of Ships and Planes
By 1944, the American counterattack against Japan’s aggression was in full flood. The losses at Pearl Harbor and thereafter had been made good with what was virtually a new navy and air force, and a series of invasions had taken the Gilbert and Marshall Islands from the Japanese.