On August 6, 1945, the United States military detonated the atomic bomb “Little Boy” 1,900 feet above Hiroshima, Japan, causing initial casualties of over 70,000. Three days later, “Fat Man” was detonated 1,540 feet above Nagasaki, causing initial casualties of over 40,000. After six days of debate between Japanese Emperor Hirohito and his military leaders, an announcement of unconditional surrender was delivered on August 15, effectively ending the Second World War. Debated to this day is the issue of whether these two weapons were needed to force Japan’s surrender.
On July 26, 1945, Allied forces signed the Potsdam Declaration giving Japan an ultimatum of unconditional surrender. If refused, the declaration would result in “the inevitable and complete destruction of the Japanese armed forces and just as inevitably the utter devastation of the Japanese homeland.” Japan did refuse and prepared for an invasion of the home islands. The Japanese felt that the expected high Allied casualties might work in their favor to negotiate better surrender terms. Four conditions were sought: preservation of the Imperial institution, responsibility for their own disarmament, no occupation, and responsibility to conduct any war crime trials.
Amphibious invasions never carry a guarantee of success, but they usually involve great cost in lives. The conquest of Okinawa had cost the Allies (mostly Americans) more than 84,000 casualties; Japanese forces suffered nearly 83,000 casualties, not counting the more than 75,000 listed among the Japanese civilian population. The shock of these extremely high losses sparked an inquiry by the U.S. government. Yet, an invasion for Japan had to be planned.
Operation Downfall consisted of two parts, one in October 1945 and the second in the spring of 1946. Japan’s geography made the plans obvious to the Japanese and they would adjust their defensive plans accordingly. Depending upon Japanese civilian resistance, American casualty estimates ranged from 1.7 to 4 million, with 5 to 10 million for the Japanese.
Such unusually high casualty estimates for the invasion, combined with the Japanese refusal to accept the ultimatum, caused President Harry S Truman to force Japan’s hand. Hiroshima and Nagasaki ultimately were chosen as targets because of their military value. Radio Saipan broadcast warnings across Japan between bombings, but no reaction came from Japanese authorities.
Following the second bombing, the Soviet Union declared war and invaded occupied Manchuria. The culmination of events between August 6th through 9th caused Emperor Hirohito himself to broadcast his decision to accept unconditional surrender to spare the Japanese people from further destruction.Below the Atlantic and Pacific victory pavilions within the World War II Memorial, there are lists of several of the campaigns and battles that brought about the end of the war. The Freedom Wall’s 4,048 Gold Stars represent the 405,399 Americans who paid the ultimate price for that ultimate victory; the blood spilled from fully 150,000 of these fallen American heroes led to Japan’s shores—and victory.
Last updated: May 12, 2020