Who decided to drop the bomb?

Pedantry about atomic politics

The short answer to the question Who decided to drop the bomb on Hiroshima? is “President Truman.” That’s what people have been writing this last week, when talking about Oppenheimer, most notably Janan Ganesh in the FT. Trouble is, the short answer isn’t really good enough for something this big. So I’m going to give you the long answer.

This might seem pedantic, but the Presidential fallacy runs deep. A lot of political commentary amounts to “Look! Something happened. And this guy is President… It must have happened because of him!” That’s not quite what Ganesh is doing, to be clear, but it’s worth seeing the complexity behind the simple statement. Rather than speculate about counter-factuals, I’m just going to try and tell you how the decision was made to drop the atomic bomb.

Before I do, let me say, that I agree with this, from Ganesh, very strongly.

It is hard for some liberals to accept we owe our world to a failed haberdasher from Missouri: a mule-trader’s son, a figure of suave derision until, in his sixties, he became perhaps the most powerful human being who’ll ever live.

Truman is a superb example of a late bloomer and great President. Were it not for space considerations—and the fact that several excellent recent biographies exist—I would have written a lot more about him in my book.

This is the paragraph I am seeking to elaborate on—

The fact that J Robert Oppenheimer agonised over his part in the creation of the atomic bomb is not interesting. Was he meant to whistle to work? Harry Truman, to whom it fell to use the “gadget”, is the more dramatic figure, precisely because he made what might be the most history-altering executive decision since Pontius Pilate without much in the way of outward qualms.

Of course, in one big sense, it was Truman’s decision and his alone. He was the President. They don’t do it if he tells them not to. But this was a decision Truman would have had to stop, or in some sense to unmake.

Before he became President, Truman hadn’t even known about the bomb. He walked in on a project that had run for years, and was running on the assumption that the bomb would be used. When Secretary of War Henry Stimson and General Groves briefed Truman, some two weeks into his new job, they gave him a twenty-four page report. He complained about the length but they said this was the most concise it could be. At the end of this report, Stimson recommend setting up a committee, to recommend action. He also emphasised the role the bomb would have in ending the war.

It is often the advisors who hold the power. Truman is no dupe. He was perhaps the most impressive President of the twentieth century when it comes to paying attention to detail and making important decisions. But Stimson and Groves were in control. Truman had just been let in on one of the most profound, complicated, and morally fraught secrets in history. What else was he going to do? Stimson even had to persuade Truman to nominate a representative to the committee.

There is the wider culture around the project to consider. In his recent book The Trials of Harry S. Truman, Jeffrey Frank quotes the Assistant Secretary of State, William Clayton,

So far as I can remember, the question as to whether the atomic bomb should be dropped… was never voted on or seriously discussed in any meeting… I think it was just accepted as settled policy.

According to the physicist Arthur Holly Compton, dropping the bomb was “a foregone conclusion.” And the committee that was making the recommendations was headed by one Henry Stimson. Unsurprisingly, that committee reported unhesitatingly that “the bomb should be used against Japan as soon as possible.” Richard Rhodes thinks this was when Truman decided to use the bomb, albeit no official decision was taken at that point.

Interestingly, it was Truman’s nomination to the committee, Secretary Byrnes, who pushed for them to conclude that way, while Stimson was absent. Stimson was worried about bombing cities from the start, something he always opposed on humanitarian grounds. He worked hard to get Kyoto, “the Rome of Japan”, removed from the target list. He was appalled by the bombings of Dresden and other cities in the war. He felt the West had been degraded by its actions. Oppenheimer may have been flippant about Truman, but the worse caricature was of Stimson, whose noble role in saving Kyoto was treated far too lightly.

So to some extent, Stimson was sidelined by Byrnes who got the committee to make the decision it was always going to make. You do not enter a race against evil to create a weapon of mass destruction without intending to use it.

His humanitarian concerns do not mean Stimson was against the use of the bomb. When he got the cable about the successful test of the weapon later on, he asked Eisenhower what he thought. Eisenhower told Stimson he disliked the idea of using such a weapon. “Well the old gentleman got furious,” Eisenhower recalled. Stimson had pushed for this project, and been right to, thought Eisenhower. Even he could see, despite the moral dilemma, that this was in some sense inevitable.

Here’s how the Dictionary of Biography puts it, my emphasis.

Stimson himself appointed and chaired a special advisory body, the Interim Committee, to make recommendations to the president concerning the use of the bomb. Stimson, like most members of the committee, had assumed from the outset that if the bomb became operational before the war ended, it would be used. While heavily influenced by a desire to end the war as quickly as possible and to avoid an invasion of the Japanese home islands, Stimson also sensed that use of the bomb might strengthen America’s position in postwar negotiations with the Soviet Union and that a demonstration of the bomb’s unprecedented power might also make the postwar control of atomic energy more likely.

The committee reported on June 1st. On June 18th, Truman summoned a group of military advisors to ask their opinion on how to bring the war to as quick a close as possible. General Marshall wanted three-quarters-of-a-million troops for a ground invasion. The others agreed. Apart from Assistant Secretary of War John McCloy. Prompted by Stimson, he said Truman should consider the bomb. A. J. Baime quotes McCloy saying, “even in that circle, it was sort of a shock. You didn’t mention the bomb out loud… it wasn’t done.”

This was still ahead of a successful test. In the meantime, a report on the costs of a ground invasion was produced by Stimson. It concluded such an invasion would be “long, costly, and arduous.” The assumption was that Japan would refuse to surrender. And that it would therefore become a long and bloody battle. The question was obvious—can we take another route? Naturally, Stimson’s report did not mention the bomb explicitly.

On July 21st, Truman received a memo from General Groves. The test had worked.

For a brief period there was a lighting effect within a radius of 20 miles equal to several suns in midday; a huge ball of fire was formed which lasted for several seconds. This ball mushroomed and rose to a height of over ten thousand feet.

Windows were shattered a hundred-and-twenty-five miles away. From here, the Potsdam Declaration was developed, which gave Japan the ultimatum to surrender unconditionally or face “prompt and utter destruction.”

This declaration was rejected. On 24th July, Truman met Stimson. No official record of this meeting exists. Truman wrote in his diary.

The weapon is to be used… I have told the Sec. of War Mr. Stimson that military objectives and soldiers and sailors are the target and not women and children.

Note the passive construction, the weapon is to be used. This had seemed almost inevitable for some time. Importantly, the decision about where to drop the bomb was a military one. Truman believed, as he wrote to Senator Richard Russell, that he wanted the swiftest end with the least loss of innocent life. But he didn’t choose where to drop the bomb. Arguments from Marshall and others were for a city. Truman followed his generals, though Kyoto was saved thanks to Stimson.

None of this is to try and say Truman didn’t make the decision. He has to bear the ultimate responsibility, but he did not initiate the decision in the form it was made. He was guided and advised within an institutional culture that assumed that the bomb would be used, especially once the costs of a land invasion were calculated.

When we say, “The President decided…” it sounds so simple. But the moral, technical, and logistical implications of the atomic bomb could never be that simple. Nor the decision making. Truman was right to take full responsibility, but it’s not quite right for us to keep repeating the claim that Harry Truman decided to use the atomic bomb.