I like to think of myself as a student of World War II history. It is a fascination of mine, particularly the experiences of infantry soldiers, in part because my generation (men who came of age in the late 1970s and early 1980s) were completely spared any combat of our own. Today, of course, is the 66th anniversary of the bombing of Hiroshima in Japan that was the beginning of the end of the war. Knowing what I know from reading -- and sensitive to what I most certainly do not know from experience, namely, what Paul Fussell* called "having to come to grips, face to face, with an enemy who designs your death," i.e., the experience of combat by front-line infantry troops -- I have no compunction in saying that the bombing of Hiroshima with a small nuclear weapon was completely justified. Japan's Army of some two million men was still intact, and the beaches of Kyushu and Honshu, the main Japanese islands, were heavily fortified. The Japanese population was committed to dying for their Emperor in a sort of mass kamikaze suicide. The casualties that would have occurred, not just on the American and British side, but on the Japanese side too, would have dwarfed the hundreds of thousands killed in Hiroshima and Nagasaki, and the terror and horror and inhumanity of non-nuclear combat in modern warfare is certainly not ontologically different, and may even be worse than the instantaneous obliteration of those cities, however horrible it may have been. Read about Stalingrad one time if you want to see what man can do to man, even without atomic bombs.
Perhaps the best comment on the decision by Truman to drop the bomb came from Winston Churchill:
There were those who considered that the atomic bomb should never have been used at all. I cannot associate myself with such ideas… I am surprised that very worthy people—but people who in most cases had no intention of proceeding to the Japanese front themselves—should adopt a position that rather than throw this bomb we should have sacrificed a million American and a quarter of a million British lives…
* In a great essay called "Thank God for the Atom Bomb," which can be found here.