In July 1945, the American Secretary of War, Henry L. Stimson, commissioned a study on the human cost of an invasion of Japan. It estimated between 1.7 million and four million Allied casualties with 400,000 to 800,000 dead and between five and ten million Japanese dead. So many Purple Hearts (awarded to US soldiers wounded or killed in combat) were manufactured in preparation for the invasion and its expected feats of death—some half a million—that the stockpile has not been exhausted to this day, many wars and nearly eighty years later.
