Hell To Pay: Operation Downfall and the Invasion of Japan, 1945-1947 is the most comprehensive examination of the myriad complex issues that comprised the strategic plans for the American invasion of Japan. U.S. planning for the invasion and military occupation of Imperial Japan was begun in 1943, two years before the dropping of atom bombs on Hiroshima and Nagasaki. In final form, Operation Downfall called for a massive Allied invasion—on a scale dwarfing “D-Day”-- to be carried out in two stages. In the first stage, Operation Olympic, after the dropping of multiple atom bombs the U.S. Sixth Army would lead the southern-most assault on the Home Island of Kyushu to secure airfields and anchorages to support the second stage, Operation Coronet, a decisive invasion of the industrial heartland of Japan through the Tokyo Plain, 500 miles to the north, led by the First and Eighth armies. These facts are well known and have been recounted— with varying degrees of accuracy— in a variety of books and articles. A common theme in these works is their reliance on a relatively few declassified high-level planning documents. An attempt to fully understand how both the U.S. and Japan planned to conduct the massive battles subsequent to the initial landings was not dealt with in these books beyond the skeletal U.S. outlines formulated nine months before the initial land battles were to commence, and more than a year before the anticipated climactic series of battles near Tokyo. On the Japanese side, plans for Operation Ketsu-go, the “decisive battle” in the Home Islands, have been unexamined below the strategic level and seldom consisted of more than a rehash of U.S. intelligence estimates of Kamikaze aircraft available for the defense of Kyushu. Hell To Pay examines the invasion of Japan in light of substantial new sources, unearthed in both familiar and obscure archives, and brings the political and military ramifications of the enormous casualties and loss of material projected by trying to bring the Pacific War to a conclusion by a military invasion of the island. This ground breaking history counters the revisionist interpretations questioning the rationale for the use of the atom bomb and shows that the U.S. decision was based on very real estimates of the truly horrific cost of a conventional invasion of Japan.