No single military event in history had long term consequences so profound as the dropping of the atomic bomb on Hiroshima on August 6, 1945. It was not simply that a city full of people died horribly that had happened, before, and even on a slightly larger scale, in several conventional "fire raids" during World War II. But those previous raids had required on the order of a thousand planes; Hiroshima was destroyed by a single plane dropping a single bomb. By simple extension, a thousand nuclear armed planes could destroy a thousand cities in a single raid: civilization could be incinerated in a day.
It is usually in the broad, long term and moral context that the atomic bombing of Hiroshima (and of Nagasaki three days later) has been considered. But it was also a military operation of war and seemingly a decisive one, since Japan surrendered unconditionally within days. President Harry Truman called it "the greatest thing in history."1 Other Americans at the time greeted the atomic bombings with almost universal relief, even joy none more so than the half million men who were slated to hit the beaches of Japan in an amphibious invasion planned for 1946. Based on the experience of invading Japanese held Pacific islands such as Iwo Jima, they had every reason to expect the worst.2 American military planners anticipated that casualties in the invasion and reduction of Japan would be comparable to the total already suffered in both the European and Pacific theaters since the U.S. entered the war.
1John Lukacs, 1945: Year Zero (Garden City, NY: Doubleday, 1978), 150.
2Richard Rhodes, The Making of the Atomic Bomb (New York: Simon & Schuster, 1988), 593 95. But was the atomic bombing actually decisive? Or was it simply "insult added to injury" a final, unnecessary blow delivered against an enemy already driven to his knees and on the verge of surrender? Or, the most cynical theory...