The Japanese people were not going to surrender until they saw the mass destruction caused by the two atomic bombs. I believe Truman felt that the "shock and awe" of those was the only way the war was going to end without losing many more American lives.
There was no good way out of the predicament Truman found himself in. His actions were extreme as a means of finally bringing the Japanese military into a surrender. Civilian death and destruction is always a casualty of war, and do not forget that the Japanese drew the US into the war.
The use of the atomic bombs dropped on Hiroshima and Nagasaki brought a very abrupt end to World War II. While it is true that thousands of innocent people perished, it also got the point across. The United States wanted an unconditional surrender after the first bomb was dropped (August 6, 1945) but the Japanese did not want to surrender unconditionally. This is why the second bomb was dropped (August 9, 1945). On August 16 the Japanese officially surrendered and signed the Japanese Instrument of Surrender.
I do not think that Truman had many options available either. Invading would have brought just as much death in the long run.
Truman believed that the use of the atomic bomb on Hiroshima was defensible because it effectively shortened the war and saved the lives of many Americans. However, after the fact, history has brought to light the fact that other options were left unexplored that might have been able to end the conflict without the need for such a degree of escalation. Truman acted more out of a need for revenge than from the voice of a calm and reasoned diplomat. His own papers state:"The Japanese began the war from the air at Pearl Harbor. They have been repaid many fold."
("Public Papers of the Presidents: Harry S Truman, 1945", pg. 197). It was his contention that we had the right to use the bomb, but having the right ti do something does not automatically make it the right thing to do.
In my opinion, weapons of mass destruction should only be considered as a last resort, when all other efforts have failed, and when there is a clear and immediate danger to self and to national security. Whether or not these conditions were met against Japan is subject to interpretation. The Japanese had bombed Pearl Harbor. The United States wanted to retaliate, and they did with as much force as they could muster, but whether or not this was a reasonable reaction or an act of retribution is definitely subject to debate.
After the fact, many Americans spoke out against Truman;s decision. Dwight Eisenhower, for instance, voiced:
grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and secondly because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment was, I thought, no longer mandatory as a measure to save American lives (Dwight Eisenhower, Mandate For Change, pg. 380)
Admiral Leahey voiced his concern that the use of this weapon had future implications that could potentially lead to more violence and could open a door to the use of Weapons of Mass destruction in the future for even less compelling reasons. He stated:
The lethal possibilities of atomic warfare in the future are frightening. My own feeling was that in being the first to use it, we had adopted an ethical standard common to the barbarians of the Dark Ages. I was not taught to make war in that fashion, and wars cannot be won by destroying women and children(William Leahy, I Was There, pg. 441)
Hebert Hoover, too, was repulsed by its use:
The use of the atomic bomb, with its indiscriminate killing of women and children, revolts my soul (quoted from Gar Alperovitz, The Decision to Use the Atomic Bomb, pg. 635)
The consensus, it seems, is that the war was essentially over and the only purpose served by dropping the bomb was not victory but retribution, never a good reason for the wide-scale slaughter of people, many of whom had no connection to the war outside of the fact that they happened to have been born and resided in Japan.
It is an interesting question for discussion, but at the same time, it wasn't possible in 1945 for our government or our military to have decided anything other than what they did. The weapon cost $2 billion to develop, and it was developed with the full intent to use it on Germany. So in effect, the decision had already been made.
If our leadership believed there was any way using the bomb would save American lives at that time, they would not have, and did not, hesitate to order its use.
Should they have done differently? Morally? Yes, I believe so. Japan was conquered and defenseless. Their empire was gone, and ours was assured. Why did we need to invade? Why not blockade? But hindsight is 20/20, and in the mood of the times, with the hatred we held for the Japanese, deciding something different than what they did was just not possible.
You will get much in way of heavy discussion on this topic. Reading Einstein's letter to FDR and the American Government about the use of atomic energy in war is fascinating. Such warning reflects that the government had knowledge that was it was dropping was going to be cataclysmic. Having said this, I think that it is difficult to assess whether or not Truman did right in dropping the bomb or if he is guilty of war crimes for doing so. I certainly believe that there is a valid argument about complete fear of how the Japanese might have been a formidable force, capable of kamikaze tactics which would have killed more American troops. However, there was significant evidence to suggest that the tactic of "island hopping" was working and that the Japanese advance was being slowed and repelled. There was evidence that the Japanese threat was not as dire as one would have thought to justify the use of the bomb. At the same time, another line of argumentation suggested that a demonstration of the device might have been enough to bring Japan to the negotiation table instead of actually dropping it. The human cost of life and damage as a result of the dropping of the atomic bomb is something that is of significant analysis, especially considering the humanitarian approach struck by the United States in the liberation of death and labor camps all over Europe. Simply put, I think that it is a complex issue where both sides have relevant information and credible arguments. Perhaps, the larger issue might have been one of inevitability in that the race for atomic energy was something that one of the superpowers would have laid claim to before the other. In this case, America got their first.
I do not think Truman had any other good choices. People say that the atomic bomb was horrible, but:
- If the US had invaded, it would first have continued bombing Japanese cities even more vigorously with conventional bombs. This would have killed just as many people, if not more.
- If the US had invaded, it would first have continued to blockade Japan and Japanese civilians would have been even worse off in terms of having food and other necessities.
- If the US had invaded, huge numbers of Americans and Japanese would have died.
If you weigh these against the cost of the A-bombs, it seems pretty clear to me that Truman made the right choice since the Japanese were not in any mood to surrender.
I don't think that Truman acted out of a need for revenge as his personal views are probably not revealed in his papers. It appeared at the time that the US may still lose the War, and there was no clear signal that the allies would win. If a bomb was in our arsenal and we failed to use it and lost, history and mostly our citizenry would never get over that fact. Since it was in our arsenal and we were in the middle of a war, it should have been used by all means.