This approach to the issue is, IMO, too simplistic. First, I would hardly call the Japaneese “helpless” in the summer of 1945. Additionally, it fails to take into consideration the fact that thousands of American lives would have been lost attempting to pacify the Japaneese archipelago. Similarly, it neglects the very real desire most Americans had for revenge. Whether or not revenge is a proper emotion with which to enter into a decision of the magnitude Truman did in August '45, is another question, though. He obviously took it into consideration, as he explained to the American people on Aug. 12, 1945:
“We have used (the bomb) on the people who attacked us without warning at Pearl Harbor, against those who have starved and beaten and executed American prisoners of war, against those who have abandoned all pretense of obeying international laws of warfare. We have used it in order to shorten the agony of war…”
Most Americans who would have born the brunt of the pacification of Japan in 1945 and 1946 were thankful for his decision. Paul Fussell, the reknowned literary historian and critic, has written as much in his 1988 essay, “Thank God for the Atom Bomb,” (sadly, I have this only as an offprint without a citation of the book from which it was taken). Fussell, who fought in and was injured in WWII, was part of a division scheduled for a potential 1946 invasion of Honshu. He writes,
"When the atom bombs were dropped and news began to circulate that “Operation Olympic” would not, after all, be necessary, when we learned to our astonishment that we would not be obliged in a few months to rush up the beaches near Tokyo assault-firing while being machine-gunned, mortared, and shelled, for all the practical phlegm of our tough facades we broke down and cried with relief and joy. We were going to live. We were going to live to adulthood after all. The killing was all going to be over, and peace was actually going to be the state of things…
"The purpose of the bombs was not to “punish” people but to stop the war. To intensify the shame (Glenn) Gray insists we feel, he seems willing to fiddle with the facts. The Hiroshima bomb, he says, was dropped “without any warning.” But actually, two days before, 720,000 leaflets were dropped on the city urging everyone to get out and indicating that the place was going to be (as the Potsdam Delcaration has promised) obliterated. Of course, few left.
“Experience whispers that the pity is not the we used the bomb to end the Japaneese war but that it wasn’t ready in time to end the German one. If only it could have been rushed into production faster and dropped at the right moment on the Reich Chancellery or Berchtesgarden or Hitler’s military headquarters in East Prussia (where Colonel Stauffenberg’s July 20 bomb didn’t do the job because it wasn’t big enough), much of the Nazi hierarchy could have been pulverized immediately, saving not just the embarrassment of the Nuremberg trials but the lives of around four million Jews, Poles, Slavs, and gypsies, not to mention the lives and limbs of millions of Allied and German soldiers. If the bomb had only been ready in time, the young men of my infantry platoon would not have been so cruelly killed and wounded.”
Clearly Fussell is a very skilled writer and writes from a perspective very close to the heart of the matter. In his wonderful book, Just and Unjust Wars (1977), Michael Walzer specifically considers arguments in favor of the bombings such as those put fort by Fussell, but rejects them:
“It had to do with our war aims. The military estimate of casualties was based not only on the belief that the Japaneese would fight to the last man, but also on the assumption that the Americans would accept nothing less than unconditional surrender. The war aims of the American government required either invasion of the main islands…, or the use of the atomic bomb. Given that choice, one might well reconsider those aims. Even if we assume that unconditional surrender was morally desirable because of the character of Japaneese militarism, it might still be undesirable because of the human costs it entailed… If people have a right not to be forced to fight, they also have a right not to be forced to continue fighting beyond the point when the war might be justly concluded. Beyond that point, there can be no supreme emergencies, no arguments about military necessity, no cost accounting in human lives. To press the war further than that is to re-commit the crime of aggression. In the summer of 1945, the victorious Americans owed the Japaneese people an experiment in negotiation. To use the atomic bomb, to kill and terrorize civilians, without even attempting such an experiment, was a double crime.” (pp. 267-8)
I think Walzer makes important points. They are arguments for peacetime, though, that during war, take a backseat to emotion and the polarization of finer sentiments created by combat. In 1945, I don’t think it was politically or emotionally possible for any American leader to calmly sit down and engage in an “experiment in negotiation” with Japan. The next most expedient and least costly solution for the Americans, the victors of the war, after all, was the use of the bomb. I do not see waiting out the Japaneese through months or years of sanctions as a credible alternative. Nor do I think that by illustrating our power by dropping a bomb off the coast, we would have forced the Japaneese to surrender unconditionally. Moreover, fallout, one of the dangers of atomic warfare we came to understand later, would have done plenty of damage in any case. Regardless of how much war is discussed and debated during peacetime, it will never be sanitized. And decisions on when and how to manipulate technology for killing, will continue to be contentious and the source of moral debate.