In the summer of 1945, President Harry Truman found himself searching for a decisive blow against the Empire of Japan. Despite the many Allied victories during 1944 and 1945, Truman believed Emperor Hirohito would urge his generals to fight on. America suffered 76,000 casualties at the battles of Iwo Jima and Okinawa, and the Truman administration anticipated that a prolonged invasion of mainland Japan would result in even more devastating numbers. Even so, plans were drawn up to invade Japan under the name Operation Downfall.
The estimates for the potential carnage were sobering; the Joint Chiefs of Staff pegged the expected casualties at 1.2 million. Staff for Admiral Chester Nimitz and General Douglas MacArthur both expected over 1,000 casualties per day, while the personnel at the Department of the Navy thought the totals would run as high as four million, with the Japanese incurring up to 10 million of their own. The Los Angeles Times was a bit more optimistic, projecting one million casualties.
With those numbers, it’s no wonder the US opted to (literally) take the nuclear option by dropping Little Boy on Hiroshima on August 6, and then Fat Man on Nagasaki on August 9. Japan formally surrendered 24 days later, sparing potentially millions of US servicemen and vindicating the horrifying-yet-necessary bombings.
At least this is the common narrative we’re all taught in grade school. But like so many historical narratives, it’s an oversimplification and historically obtuse.