D. M. Giangreco, "Hell to Pay: Operation Downfall and the Invasion of Japan, 1945-1947", Naval Institute Press, Annapolis, 2009
Giangreco, a longtime former editor for Military Review, synthesizes years of research in a definitive analysis of America's motives for using atomic bombs against Japan in 1945. The nuclear bombing of Japan, he concludes, was undertaken in the context of Operation Downfall: a series of invasions of the Japanese islands American planners estimated would initially cause anywhere from a quarter-million to a million U.S. casualties, plus millions of Japanese.
Giangreco presents the contexts of America's growing war weariness and declining manpower resources. Above all, he demonstrates the Japanese militarists' continuing belief that they could defeat the U.S.
Japan had almost 13,000 planes available for suicide attacks, and plans for the defense of Kyushu, the U.S.'s initial invasion site, were elaborate and sophisticated, deploying over 900,000 men. Japanese and American documents presented here offer a chillingly clear-eyed picture of a battle of attrition so daunting that Army Chief of Staff George C. Marshall considered using atomic and chemical weapons to support the operation.
Faced with this conundrum, in Giangreco's excellent examination, President Truman took what seemed the least worst option.
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A former editor at Military Review provides us with one of the first books to detail the planned U.S. invasion of the Japanese home islands in October 1945 and the Japanese preparations for that invasion. Drawing on solid research in both countries, Giangreco lays out the U.S. planning and the whole scenario of what would have happened: millions of casualties, prolongation of the Pacific war, possibly past 1947, and manpower shortages and war weariness in the United States, with Japanese militarists and their no-surrender policy in control in Japan.
The two-pronged invasion would have begun on the island of Kyushu, preceded by no fewer than nine atom-bomb drops behind the landing beaches. Illustrative of just how much the war with Japan was a close-run thing, this is essential reading.