Operation Downfall

70 years ago, on November 1, 1945, the invasion of Japan was scheduled to take place. The first part of Operation Downfall was the invasion of the southernmost island of Japan, Kyushu, this was called Operation Olympic. It was only intended to occupy the southern part of the island and would serve as a base of operations for Operation Coronet, the invasion of the main island of Honshu near Tokyo, scheduled for spring of 1946. It would have been the largest amphibious operation in the history of war. The possible invasion beaches of the island of Kyushu were well known to the Japanese and they intended to defend them to the death. While there was no possibility of winning the war, Japan’s leaders thought that by making the cost of the war to high for the Allies, they could get better terms of surrender. Japan’s own plans for the defense of Kyushu, Operation Ketsugo, Included thousands of Kamikaze aircraft, hundreds of suicide midget submarines and a good number of their ground forces, leaving little in reserve for the defense of Honshu. In addition they planned to train and arm much of the civilization population to help in the fight. Because of the number of forces facing the Allies and the additional threat of a possible armed civilian army, an investigation was made into the tactical use of atomic bombs to drop behind the beachheads and on Kyushu cities. At least seven ‘Fat Man’ plutonium bombs could be made available by the invasion date. The radiation risk of nuclear fallout was not well known and it was thought that by waiting 48 hours before occupying a bombed area, it would minimize the exposure. The U.S. had been pressuring the Soviet Union to declare war on Japan and had provided them about 100 naval vessels, including amphibious assault ships for them to use in their own invasion of Japan. Based on the number of killed and wounded during the difficult battle for Okinawa, estimates of casualties for the invasion varied widely but a figure of a half-million men, killed, wounded or missing was the generally accepted figure. To this end, 500,000 Purple Heart medals were created for the anticipated wounded. With a war-weary population in the U.S. who would not understand the high casualties necessary to invade and occupy Japan, it was decided to try the newly available atomic bombs on Japan cities first. These, along with the Soviet Union’s declaration of war on Japan on August 8th convinced the Japanese of the futility of their position and on August 15th they surrendered. The use of atomic bombs on the Japanese civilian population is now widely condemned, but the horrific fighting that would have come with a land invasion would have been far more devastating to both sides. I still feel that the incredibly difficult choices at the time did not leave much room for any other decision. (Below, my photograph of the Enola Gay, which dropped the first atomic bomb on Hiroshima, August 6, 1945, on display at the Smithsonian Air and Space Museum.)