A long time ago I posted some thoughts on America's use of the atomic bomb at the end of World War II. I happen to be reading parts of Gabriel Kolko's classic The Politics of War, and his investigations of the issue have gotten me interested in it again. Not least because I sometimes discuss it in university classes, so I should have a firmer knowledge of the history than I do. After reading some academic articles, I've realized that (some of) my earlier conclusions, based on Gar Alperovitz's book, were inadequate. I still think it was a terrible crime that illustrated the amorality of most political leaders, but my earlier judgments were a little simplistic.
Since most people are unaware of the scholarship and there's a colossal amount of ignorance out there about this controversial topic, here are a few comments...
Let's look at what Kolko says. He's arguably one of the greatest American historians of the twentieth century, so he's worth taking seriously. Unlike some of the revisionists (critical of Truman) who argue that the Japanese government was desperate for peace and on the verge of surrender by July 1945, he's aware of the profound divisions in that government between militarists who wanted to continue the war and liberals who wanted to end it as soon as possible (not unconditionally but with an assurance that the Emperor could remain on the throne). The Americans knew of these disagreements among Japanese officials, that a peace faction was contending against the intransigence of the army. In late May 1945, Joseph Grew, a high official in the State Department, "won the President's support for a proposal to offer the Japanese surrender terms permitting them to retain the Emperor if they chose, which in fact was the American position since the year before." But Truman, the Joint Chiefs of Staff, and Secretary of War Henry Stimson wouldn't yet authorize a public offer to the Japanese, since they thought (for some reason) the situation wasn't ripe for a public change in policy. It wasn't until the Potsdam Declaration on July 26 that an "offer" (or ultimatum) was made. Meanwhile, Truman decided not to warn Japan of the possibility of an atomic attack.
At Potsdam, the Americans were very eager to get from Stalin (to quote Truman) a "reaffirmation of Russia's entry into the war against Japan, a matter which our military chiefs were most anxious to clinch." The prospect of an American invasion of Japan was dreadful—although, as more recent scholarship has established, estimates given by Truman and others after the war that an invasion would have caused hundreds of thousands of American casualties or even fatalities were hardly discussed at all among officials at the time, nearly all of whom (including Truman, it seems) thought such figures "entirely too high." Around 25,000 fatalities was the usual estimate. Even General Curtis LeMay said in October 1945 that the atomic attacks had saved "thousands of lives"—and he had every reason to inflate the numbers for public consumption, so it's significant that he didn't. (See J. Samuel Walker's 2005 review of the scholarly literature for a discussion of casualty estimates.)
Anyway, during the Potsdam Conference the Americans heard news of the first successful test of the atomic bomb. Winston Churchill's reaction was characteristic of the man:
Churchill was the first to realize the bomb had political and military significance... Field Marshal Alan Brooke thought the Prime Minister's infantile enthusiasm bordered on the dangerous: "He was already seeing himself capable of eliminating all the Russian centres of industry... He had at once painted a wonderful picture of himself as the sole possessor of these bombs and capable of dumping them where he wished." He tried to communicate the fantasy to his associates, but they resisted it, and he [unsuccessfully] urged Truman to dispense with the aid of the Russians in the war.
On July 24, Truman, Churchill, and the Combined Chiefs of Staff had a meeting wherein "they agreed that the military situation still necessitated an invasion of Japan, requiring perhaps a million or more men. They did not expect the bomb to alter that fact." So there goes the conventional retrospective defense of American decision-making that it was either invasion or the atomic bomb, and the Americans dropped the bomb to make an invasion unnecessary. Truman himself used this justification in later years, but he was simply lying or had a faulty memory. As the judicious and unpartisan Samuel Walker writes in his 2005 article, "In the summer of 1945, the president and his chief advisers never weighed a decision between the bomb and an invasion as an either/or proposition. This was a postwar construct that followed the dichotomy drawn by Stimson, Truman, and other policymakers in their [later] explanations for using the bomb. During the last weeks of the war, they were keenly aware of alternatives to an invasion other than the bomb."
So actually, despite the meeting on July 24, American leaders were not at all certain that an invasion would be necessary (although they continued to plan for it). This is clear from Truman's diary entries, for example, and the statements of high-ranking army officials. They evidently hoped, for instance, that the staggering blow of Russia's entry into the war would eventually help persuade the Japanese to surrender. On the other hand, General George Marshall, at least, thought that if it came to an invasion, six to nine atomic bombs should be used to support the American forces.
On July 24 "Truman sent instructions to the Air Force to drop the first bomb as soon as it was ready, and weather permitted, 'after about August 3rd,' and to deliver the rest on four target cities 'as soon as made ready.'" Kolko's judgment is that "the bomb was built to be dropped [and] no one ever had the slightest doubt America would use it." As General Leslie Groves later said, "As far as I was concerned, [Truman's] decision [to use the bomb] was one of noninterference—basically, a decision not to upset the existing plans."
The original draft of the Potsdam Declaration had a clause saying the Emperor could be retained, but Secretary of State Byrnes excised it because it might appear to be a retreat from unconditional surrender. The Joint Chiefs of Staff supported the revision, against Stimson and Grew, who thought retaining the clause might help strengthen the Emperor and liberals against the hard-line army. Of course, we can't know how the Japanese would have reacted to the Declaration if the clause had been retained. From later scholarship—contrary to the arguments of anti-Truman revisionists—it's highly unlikely they would have surrendered right away. But it might have, sooner or later, given the upper hand to the liberals in Japan's government who had already been reaching out, albeit awkwardly and tentatively, to "neutral" parties like the Russians to try to broker peace. Especially since the devastating naval blockade of Japan, the continuing destruction of the country's agricultural, industrial, and transportation resources, the diminishing morale among soldiers and civilians, etc. were exerting intense pressure on the government to end the war.
After the Declaration, Foreign Minister Togo, without real support from his divided government, continued to press the Russians to explore means of ending the war without unconditional surrender—overtures the Americans were aware of (because of code-breaking) but that they did nothing about, rightly or wrongly. So the war continued, and a few days later Hiroshima was bombed. Kolko sums up the whole affair by saying, "Mechanism [i.e., bureaucratic inertia] prevailed. No one seriously explored any of the options—neither Japanese surrender, nor delay, nor withholding the bomb." He continues:
Any realistic assessment of the objective conditions of the Japanese during those weeks might have convinced a reasonable group of men that significant alternatives to prolonged war existed, but the Japanese leaders themselves were incapable of confronting their defeat and acting accordingly. For precisely the same reasons of mechanism and conservatism, which the Japanese in their own desperate way shared, the Americans decided to use the bomb as a known and now predictable factor of war, an economical means of destroying vast numbers of men, women, and children, soldiers and civilians. Well before August 1945 they had reduced this to a routine.
The United States could have won the war without the Russians and without the atomic bomb.
The last statement is an unknowable counterfactual, but it is at least plausible, and echoes the conclusion of the U.S. Strategic Bombing Survey of 1946. What is certain is that there was no moral agonizing over the decision to use the bomb, hardly even a doubt or a second thought. Stimson, for a while, didn't even want to issue any peace offer like the Potsdam Declaration until after the bombs had been dropped. Why should there be moral qualms when America had for months been firebombing dozens of Japanese cities and killing hundreds of thousands of civilians? They knew the bomb would be less destructive than all that.
It's true that the Americans wanted to end the war as soon as possible, and they obviously thought dropping atomic bombs might contribute to that. (On this point, most scholarship, including Kolko's, has concluded that Alperovitz is wrong to think the bomb was used primarily as a diplomatic weapon against the Soviets, to intimidate them.) Even if few people thought an invasion of Japan would cost hundreds of thousands of casualties, and there was actually some doubt that an invasion would be necessary at all, the longer the war went on, the more Americans would die. (And, axiomatically, saving even a few thousand American lives was worth killing hundreds of thousands of Japanese.) But then: why not try harder, publicly or through "back channels," to make peace with Japan? Of course, the Japanese leadership was even more culpable for not surrendering months earlier and saving countless lives.
But in World War II, no one cared much about saving lives.
The first bomb was dropped on August 6. The historian Sadao Asada has a good article on Japan's decision-making in the following days. The military initially denied it was an atomic bomb, but Togo called an emergency cabinet meeting on August 7 at which he argued that, lest the U.S. keep dropping such bombs, Japan should accept the Potsdam terms with the condition that the emperor system remain in place. But the army wouldn't agree—it was adamant for a decisive battle on the homeland against an American invasion—so the meeting broke up. On the 8th Togo met with Emperor Hirohito to argue for surrender, and Hirohito, who was very disturbed by the Hiroshima bombing, wholly agreed. It was arranged that the Supreme War Council would meet the next day. Early on the 9th, just before the meeting, the Soviet Union declared war, which was another terrible shock, albeit not as unexpected as the atom bomb. But the army, concerned with "honor" and the like, was still resistant to surrender. In the middle of the meeting came yet a third staggering blow: the bombing of Nagasaki, which a local commander had ordered, having been authorized by Washington to do so. The U.S. hadn't even bothered to assess the impact of the first bomb or of the Soviets' declaration of war, and Asada (among many other scholars) concludes the Nagasaki bomb was unnecessary. Meanwhile, the army still refused to surrender! Another meeting later that day resulted in the same stalemate. Shortly before midnight a conference with Hirohito was convened at which the usual debates between the army and the peace faction were reenacted, with no breakthrough. So then, "in an act unprecedented in modern Japanese history, the prime minister stepped up to the emperor, bowed deeply, and submitted the matter for an imperial decision." Hirohito ordered surrender, and later on the 10th the conditional surrender was relayed to Washington through the Swiss and Swedish governments. (It was a considerable surprise to Washington, which had expected the war to last weeks or months longer.)
In later statements, high-level Japanese officials said the "psychological shock" of the Hiroshima bomb had aided their efforts to end the war—as had the Soviet declaration of war. It is hard to say which was more important, but Asada thinks the bomb was. For one thing, he argues it allowed the army fanatics to save face: they could say they were defeated by superior science rather than "spiritual weakness" or strategic errors. As Japan's chief cabinet secretary recalled later, "The atomic bomb was a golden opportunity given by Heaven for Japan to end the war. There were those who said that the Japanese armed forces were not defeated. It was in science that Japan was defeated, so the military will not bring shame on themselves by surrendering." The bomb was a "clever pretext" for ending the war.
But surely it ultimately came down to Hirohito's decision, and he, while vacillating, had been inclined to end the war for months. Had he been a stronger person, he probably could have compelled the army to surrender weeks or months earlier.
As I indicated, the Strategic Bombing Survey of 1946 concluded that "in all probability" Japan would have surrendered before November 1, the day scheduled for an American invasion, "even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated," but some scholars have argued this conclusion was based on too little evidence. Who knows? When it comes to counterfactuals, all you can do is speculate. It does seem very likely, though, that at least with the Russian entry into war (and without the bombs), Japan would have surrendered before November.
What is clear is that the whole tragic and absurd episode of the last weeks of the war was, to quote Kolko, "testimony to the irrationality and profound immorality of all leaders and the triumph of unwavering mechanism in the war between Japan and the Allies." The scholarly literature on use of the bomb is full of incredibly detailed investigations of why it was dropped, what weight was given to various considerations, why available alternatives weren't seriously pursued, and so on, but surely there is something a little misguided about this whole endeavor. Political leaders, in brief, are not so thoughtful, not so concerned with morality or absolute consistency or the most efficient possible means of attaining carefully defined ends. They exist in an environment of overwhelming power and pressures to expand power, bureaucratic momentum, intra-bureaucratic turf wars, technological fetishism, intoxication with military technology because of its glorious power and use as a tool of intimidating others. Whatever political leaders say, their environment is power for the sake of power. "We have this great new weapon, we might as well use it!" It reminds me of Madeleine Albright's objections to Colin Powell's refusal to use the military in Bosnia in 1993: "What's the point of having this superb military that you're always talking about if we can't use it?!" Power is to be projected for its own sake. That's the only ethic of power. Leslie Groves, for example, who was mostly in charge of determining when and where to use the bomb, "was anxious to justify the effort and the expenditures of the Manhattan Project, and he avoided outlining alternatives to Truman that could change existing plans and frustrate his objectives. Thus the bomb fell more because of bureaucratic imperatives than because of carefully considered questions of national interest." (From the other article by Walker I linked to below.) And scholars who have written, in particular, about Truman's alleged pinpricks of conscience in later years are wasting their time. Who cares about Truman's conscience? He was a morally and intellectually puny man (racist, self-deceiving, authoritarian, obedient to capitalist class power, self-serving, morally unimaginative, intellectually incurious), a nonentity like most public officials.
The bomb was used for many reasons: it might help defeat the Japanese; it might help save American lives; it might help end the war before the Soviets had conquered a lot of territory in East Asia; and crucially: it projected American power to both allies and enemies; enormous resources had been poured into its construction; powerful officials had always taken for granted that the bomb would be used; hardly anyone expressed any opposition to it; political leaders are moral cowards; etc. Were the attacks on Hiroshima and Nagasaki horrific crimes? Of course. You need only a little moral common sense to see that. (Just read about the bombs' actual effects on the victims, if you can stomach such reading.) The Americans and, obviously, the Japanese could both have exerted more effort than they did at ending the war months earlier. Or, if they had cared about Japanese lives at all, the Americans could at least have bombed an exclusively military target or warned people to leave the area before the attack, as General Marshall futilely advocated. Even the sociopathic Curtis LeMay, in charge of the strategic bombing of Japan, admitted that he and the other American (and foreign) leaders were war criminals or would have been punished as such had they lost the war.
Nationalist habits of thought cause irrationality and moral imbecility, leading many people to think the atomic bombings (and the firebombing of Tokyo and other cities, also in Europe) were necessary and justified. They weren't.
 As Kolko says, by 1942 the Russians knew of the Manhattan Project and were trying to build their own bomb. "At no time did the Americans believe they could surprise the Russians with a weapon that would cause them to cower, and at every stage in their diplomacy the Russians acted with full knowledge that the United States was likely to be the first to have an atomic bomb." This isn't to say, however, that possession of the bomb was of no diplomatic importance, especially in the following years. See this other article by J. Samuel Walker.
 In fact, at first Truman rejected the surrender because it wasn't unconditional! Instead, the White House replied with an intentionally ambiguous statement that emboldened Japanese militarists once more, which required that Hirohito intervene on the side of peace again on the 14th. Meanwhile, despite the surrender, Truman had authorized the continuation of bombing raids on cities, though not the use of a third atomic bomb.