This Saturday will be the 60th anniversary of the atomic bombing of Hiroshima, Japan, by the United States of America. Given the state of education in the US and the wider world, one wonders how many people realize that the attack was not unprovoked - that the attack was part of a tactic to avoid a massive invasion of the Japan and the horrendous casualties such an invasion would have cost to both to the US and Allied Forces, as well as to the Japanese military and civilian population. That the attack ended World War II. That the Empire of Japan had invaded and butchered its neighbors, and had executed a devastating pre-emptive air strike against the US Navy at Pearl Harbor 3 1/2 years earlier, in order to prevent tue US from interfering with its war in the Pacific. That Japan was so prepared to fight to the finish that it took two atomic bombings to convince their leadership to give up. That anything less that Unconditional Surrender would have been immoral, after what Japan had done to its neighbors, because anything less than unconditional surrender would have failed to dismantle the leadership that made that war.
And now, with hindsight, one wonders whether an invasion followed by an occupation would have led to an insurgency. Perhaps the atomic bombing led the Japanese to believe that if they tried an insurgency, the occupiers would simply have withdrawn and resumed atomic bombing.
Still, there is the realization on the part of those who developed the bombs, especially Leo Szilard, that had the US lost some subsequent major conflict, those who had much to do with the atomic bombing of Japan might have been tried for war crimes. See his short story, "My Trial as a War Criminal," in The Voice of the Dolphins, Stanford University Press, 1961.
That is to say, the atomic bombings of Hiroshima and, some days later, Nagasaki, were evil in both their intent and their effects. It's just that they were less evil than the alternatives. May their like not ever happen again to any people.