Two August mornings that ended a world war’s Pacific chapter
In early August 1945, U.S. forces released nuclear weapons over Hiroshima and then Nagasaki, with estimated deaths between 150,000 and 246,000 people, mostly civilians, in World War II’s final days. Debate over ethics and necessity has never closed.
The road to the bombs began with the discovery of nuclear fission in 1938. Refugee scientists afraid that Germany would build a weapon first voiced that fear in the Einstein–Szilard letter to Roosevelt in 1939, and American research started later that year, gathering pace after a British committee’s 1941 report. The resulting Manhattan Project ran across dozens of sites, employed more than 125,000 people at its peak and cost over two billion dollars. J. Robert Oppenheimer led bomb design at Los Alamos, New Mexico, producing a uranium gun-type weapon called Little Boy and a second design called Fat Man. Japan had its own programme, but it never came close.
By 1945 the Pacific War was in its fourth year, and nearly a million of America’s 1.25 million wartime battle casualties had fallen in the twelve months to June 1945. Japan was starving of shipping: its merchant fleet shrank from 5.25 million gross tons in 1941 to about 557,000 by August 1945. Allied planners drew up Operation Downfall, with landings on Kyūshū from October 1945 and an assault near Tokyo in March 1946. Japan, correctly guessing the plan, readied 2.3 million soldiers and a civilian militia of 28 million.
Casualty forecasts varied wildly. A June 1945 staff study projected 132,500 to 220,000 American casualties, while a study for Secretary of War Henry Stimson put the figure between 1.7 and 4 million. George Marshall even weighed poison gas, and stocks of phosgene and mustard gas were shipped to Luzon.
After Britain gave the consent required under the Quebec Agreement, General Thomas Handy issued orders on 25 July naming Hiroshima, Kokura, Niigata and Nagasaki, large cities that also housed military facilities. Little Boy fell on Hiroshima on 6 August and Fat Man on Nagasaki three days later, following a firebombing campaign that had already wrecked 64 Japanese cities. They remain the only nuclear weapons used in war, and their justification is still argued.
Source: Atomic bombings of Hiroshima and Nagasaki
