The decision to drop the atomic bomb

 The recent 80th anniversary of the dropping of the atomic bomb on Hiroshima brought to mind some thoughts I'd had when I was watching the Oppenheimer movie a little while ago, and so I thought I'd finally get around to writing them up.  

Ultimately Truman thought that dropping the atomic bombs was the best way to bring about Japan's unconditional surrender and its hard to disagree about that.  The most obvious alternative at the time would have been a land invasion of Japan.  One can certainly have "clean" land combat that takes place far away from most civilian residences and which is a matter of combat between professionals.  That wasn't what had been seen recently in the Pacific war though.  The recent Battle of Manila fought as the Allies liberated the Philippines saw the death of around 20,000 soldiers but 100,000 Filipino civilians.  In taking Okinawa 100,000 soldiers died and about 100,000 of island's 300,000 civilians, some because they had been ordered to commit suicide rather than face capture.  

The Allies were expecting to lose at least 500,000 men taking Japan and several times that in Japanese soldiers.  I would guess that there was little chance of the civilian casualties actually reaching the 25 million implied by the Okinawa example but certainly the deaths would have reached the millions, maybe up to 10 million compared to the hundreds of thousands the atomic bombs cost.

Truman could have resisted the urge to invade and just patiently kept up the bombing and the starvation caused by cutting Japan off from foreign food.  That wouldn't have killed Japanese civilians at the same rate that weekly atomic bombings did but on the other hand Japan had been enduring this for quite a while and without the sudden shock of the atomic bombings there's little reason to think the boiling frog would have jumped out of the pot quickly enough to make this a better approach.

So, given the need for force Japan's unconditional surrender, I think the apologists are right that dropping the atomic bomb was the least worst option.

But of course all this assumes that the goal had to be unconditional surrender.  Japan is unique in having had a single ruling dynasty for all of its recorded history stretching back to the myth that the Emperor's are descended from the sun goddess Amaterasu.  Individual emperors have been killed or forced to abdicate in favor of someone more pliant to the whims of particular warlords, but as far as historians know the same family has ruled since at least 500 AD or so.  So while the Japanese government would have been happy with Hirohito resigning in favor of his successor to end the war with no atomic bomb, and while they might have been able to stomach Hirohito going on trail for war crimes, they couldn't accept agreeing to the end of the imperial line and Japan becoming a republic as an unconditional surrender would leave the Allies free to impose.

But of course, Japan is not a republic now.  Nor was Hirohito put on trial for the war crimes he very much did commit.  Nor was he even asked to resign to provide a nice symbolic renewal but instead we have the "Shōwa Era" in Japanese chronology awkwardly stretching from 1926 to 1989.  Instead McArthur thought that it would make his occupation of Japan easier to have the existing symbols of rule in place and so the line of the Emperors and Empresses of Japan remains the heads of state to this day, though in a ceremonial role.

The "unconditional surrender" formulation was first publicly announced by Franklin D. Roosevelt at the Casablanca Conference on January 24, 1943.  During a press conference with Winston Churchill, Roosevelt made a declaration stating that the Allies would accept nothing less than the unconditional surrender of Germany, Italy, and Japan. Churchill was caught somewhat off-guard at the time because while the concept had been discussed, the specific wording and its public announcement hadn't been fully coordinated beforehand.

And once "unconditional surrender" was the goal it was hard to step back from it.  Americans were furious after Pearl Harbor and Japan's strings of atrocities inflicted throughout the war didn't help either.  But of course presidents are allowed to do unpopular things - such a change in policy would clearly have been within Truman's power and there were people in the administration all the way up to Secretary of War Henry Stimson advocating for it.

And so we come full circle to Truman's choice but looked at from a strategic level of goals and prices rather than just a level of tactics.  Different choices could have been made to pursue very slightly different ends and the political cost for the president might have been high but the cost for America would have been something we would casually discard in the end anyways.