Science Fiction Writer
ROBERT J. SAWYER
Hugo and Nebula Winner

HOME • MENU • Search:

The Oppenheimer Alternative

Did the US Have to Drop Atomic Bombs on Japan?

"Robert — your writing on this subject is excellent. I am a professor of modern Japanese history and everything you have written reflects historiographical consensus."

—Matthew Penney, Ph.D.
Department of History
Concordia University

No one can be certain of Oppenheimer's reaction had he learned that on the eve of the Hiroshima bombing, the president knew the Japanese were "looking for peace," and that the military use of atomic bombs on cities was an option rather than a necessity for ending the war in August. But we do know that after the war he came to believe that he had been misled, and that this knowledge served as a constant reminder that it was henceforth his obligation to be skeptical of what he was told by government officials.

—from American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, the Pulitzer Prize-winning biography by Kai Bird and Martin J. Sherwin

In my 2020 novel The Oppenheimer Alternative, the following exchange occurs between J. Robert Oppenheimer and his wife Kitty (with Kitty employing a racial slur that was regrettably all-too-common during the Second World War):

     "They ... they've dropped a second bomb," Oppie said, holding her. "Apparently Kokura was clouded over, so they ..." His voice caught; he'd intended to say "they hit Nagasaki instead," but it didn't matter, he realized; they were just names to Kitty, and to him, alien syllables.
     "I'm so sorry," she said softly. Kitty was much shorter than Oppie; the words were spoken into his bony chest.
     "Why didn't they surrender?" asked Oppie. "After the first one, why didn't they surrender?"
     "Truman said it had to be unconditional," Kitty replied, still holding him. "Charlotte Serber thinks that's the problem." She disengaged from Oppie's embrace but took his hand and led him to the couch by the stone fireplace. "She thinks the Japs want to keep their emperor. They think he's divine; a god. She says unconditional surrender would be like asking the United States to agree to renounce Jesus."

Sure, in Killing the Rising Sun, often said to have been written by Bill O'Reilly, the case is made that the U.S. had to drop atomic bombs on Japan. But that's simply wrong.

From July 17 to August 2, 1945, the leaders of the "Big Three" Allied countries — Soviet General Secretary Joseph Stalin, British Prime Minister Winston Churchill (replaced on July 26 by newly elected Prime Minister Clement Attlee), and U.S. President Harry S. Truman — met in Potsdam, Germany, to negotiate terms for the end of World War II. Four days after the end of this Potsdam Conference, on August 6, 1945, the United States unilaterally dropped an atomic bomb on Hiroshima; three days later, it dropped another one on Nagasaki.

But this was unnecessary. The key issue that had come out of the Potsdam Conference, which O'Reilly and Martin Dugard, who actually wrote the book, gloss over, is that Japan was willing to surrender well before the bombs were dropped on Hiroshima and Nagasaki; they simply weren't willing to surrender unconditionally. They considered their emperor Hirohito to be divine, and they needed him to at least putatively remain as post-war head of the Japanese state (under whatever international oversight might be imposed).

The war could have ended in July 1945, or earlier, if the U.S. had been willing to forego the "unconditional" requirement. From the Pulitzer Prize-winning The Making of the Atomic Bomb by Richard Rhodes (boldface emphasis added):

On the other hand, [U.S. Secretary of War Henry L.] Stimson had argued, because of the mountainous Japanese terrain and because "the Japanese are highly patriotic and certainly susceptible to calls for fanatical resistance to repel an invasion," America would probably "have to go through with an even more bitter finish fight than in Germany" if it attempted to invade. Was there, then, any alternative? Stimson thought there might be:

I believe Japan is susceptible to reason in such a crisis to a much greater extent than is indicated by our current press and other current comment. Japan is not a nation composed wholly of mad fanatics of an entirely different mentality from ours. On the contrary, she has within the past century shown herself to possess extremely intelligent people, capable in an unprecedentedly short time of adopting not only the complicated technique of Occidental civilization but to a substantial extent their culture and their political and social ideas. Her advance in these respects ... has been one of the most astounding feats of national progress in history ....

It is therefore my conclusion that a carefully timed warning be given to Japan ....

I personally think that if in [giving such a warning] we should add that we do not exclude a constitutional monarchy under her present dynasty, it would substantially add to the chances of acceptance.

Within the text of his proposal the Secretary of War several times characterized it as "the equivalent of an unconditional surrender," but others did not see it so. Before [U.S. Secretary of State Jimmy] Byrnes left for Potsdam he had carried the document to ailing Cordell Hull, a fellow Southerner and Franklin Roosevelt's Secretary of State from 1933 to 1944, and Hull had immediately plucked out the concession to the "present dynasty" — the Emperor Hirohito, in whose mild myopic figure many Americans had personified Japanese militarism — and told Byrnes that "the statement seemed too much like appeasement of Japan."

It may have been, but by the time they arrived in Potsdam, Stimson, Truman and Byrnes had learned that it was also the minimum condition of surrender the Japanese were prepared to countenance, whatever their desperate situation. U.S. intelligence had intercepted and decoded messages passing between Prime Minister Shigenori Togo Japanese ambassador Naotake Sato in Moscow to attempt to interest the Soviets in mediating a Japanese surrender. "The foreign and domestic situation for the Empire is very serious," Foreign Minister Shigenori Togo had cabled Sato on July 11 [1945], "and even the termination of the war is now being considered privately .... We are also sounding out the extent to which we might employ the USSR in connection with the termination of the war .... [This is] a matter with which the Imperial Court is ... greatly concerned." And pointedly on July 12:

It is His Majesty's heart's desire to see the swift termination of the war .... However, as long as America and England insist on unconditional surrender our country has no alternative but to see it through in an all-out effort for the sake of survival and the honor of the homeland.

It wasn't until 1960 that the U.S. government publicly acknowledged that it had, in fact, broken the Japanese codes during the war and had intercepted and translated these cables on their sending dates, and it wasn't until 1978 that the cables themselves were made available to historians — so if you didn't hear about them in school, that may be why.

At a meeting with President Truman and others in Washington on July 18, 1945, Admiral William D. Leahy, chair of the U.S. Joint Chiefs of Staff and of the Combined American-British Chiefs of Staff, said (as quoted in The Fall of Japan by William Craig, published in 1967; boldface emphasis added):

I do not agree with those who say that unless we obtain the unconditional surrender of the Japanese that we will have lost the war. I fear no menace from Japan in the foreseeable future, even if we are unsuccessful in forcing unconditional surrender. What I do fear is that our insistence on unconditional surrender will only result in making the Japanese more desperate and thereby increase our casualty lists. I don't think this is at all necessary.

Prime Minister Togo reiterated that the Japanese were willing to surrender in a cable to Ambassador Sato intercepted on July 17, 1945, and immediately communicated to Churchill and Truman, who were by then at the Potsdam Conference. Quoting that cable, which is designated MAGIC No. 1210:

If today, when we are still maintaining our strength, the Anglo-Americans were to have regard for Japan's honor and existence, they could save humanity by bringing the war to an end.

President Truman, in his own handwritten diary for July 18, 1945 (the next day), as quoted by Kai Bird and Martin J. Sherwin in the Pulitzer Prize-winning American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, identifies this cable as being a "telegram from Jap Emperor asking for peace."

And Both Truman and Churchill well understood that by "honor and existence," Togo meant letting the divine emperor retain his throne; Churchill himself in a note to his cabinet, quoted in Grand Strategy, Volume VI: October 1944-1945 by John Ehrman and published by Her Majesty's Stationery Office in 1956, wrote:

The President [Truman] also thought the war might come to a speedy end ... I dwelt upon the tremendous cost in American life and, to a smaller extent, in British life which would be involved in forcing "unconditional surrender" upon the Japanese. It was for him [Truman] to consider whether this might not be expressed in some other way, so that we got all the essentials for future peace and security, and yet left the Japanese some show of saving their military honour and some assurance of their national existence, after they had complied with all safeguards necessary for the conqueror ...

It has been evident to me in my conversations with Mr. Stimson, General Marshall and now with the President, that they are searching their hearts on this subject, and that we have no need to press it.

And this whole insistence on unconditional surrender dated back to an off-the-cuff ad lib by now-deceased president Franklin D. Roosevelt from 1943. From Rhodes again:

The month [journalist Henry C.] Wolfe's call to aerial battle appeared in Harper's — January 1943 — Franklin Roosevelt met with Winston Churchill at Casablanca. In the course of the meeting the two leaders discussed what terms of surrender they would eventually insist upon; the word "unconditional" was discussed but not included in the official joint statement to be read at the final press conference. Then, on January 24, to Churchill's surprise, Roosevelt inserted the word ad lib: "Peace can come to the world," the President read out to the assembled journalists and newsreel cameras, "only by the total elimination of German and Japanese war power .... The elimination of German, Japanese and Italian war power means the unconditional surrender of Germany, Italy, and Japan." Roosevelt later told [U.S. Secretary of Commerce] Harry Hopkins that the surprising and fateful insertion was a consequence of the confusion attending his effort to convince French General Henri Girard to sit down with Free French leader Charles de Gaulle:

We had so much trouble getting those two French generals together that I thought to myself that this was as difficult as arranging the meeting of Grant and Lee — and then suddenly the Press Conference was on, and Winston and I had had no time to prepare for it, and the thought popped into my mind that they had called Grant "Old Unconditional Surrender," and the next thing I knew I had said it.

Churchill immediately concurred — "Any divergence between us, even by omission, would on such an occasion and at such a time have been damaging or even dangerous to our war effort" — and unconditional surrender became official Allied policy.

And it needs to be noted that the plan had long been not to bomb Japan just once but to bomb it twice. On the day of the Trinity test, July 16, 1945, General Leslie R. Groves, the head of the Manhattan Project, said the following — his own words as he himself reported them in his autobiography, Now It Can Be Told, published in 1962 (this is not new information, but it's almost always ignored in the popular-history accounts):

Shortly after the explosion, [Thomas] Farrell and Oppenheimer returned by jeep to the base camp, with a number of the others who had been at the dugout. When Farrell came up to me, his first words were, "The war is over." My reply was, "Yes, after we drop two bombs on Japan."

Two bombs. Groves was hell-bent on testing both of their two competing bomb designs — the straightforward gun-type "Little Boy" and the complex implosion "Fat Man" — on civilian populations, and as quickly as possible. From his autobiography again:

Our basic operational plans were to launch the atomic attack using the gun-type bomb as soon as the final bit of U-235 reached Tinian by air and weather permitted. As soon as possible after this, a second attack would be initiated. This time an implosion-type bomb would be dropped.

At Groves's request, a few Japanese cities had been spared the firebombing that had already ravaged Tokyo and other places precisely so that they could be used as pristine testbeds for both atomic explosions. One of Groves's own preferred targets, Kyoto, was vetoed by Secretary of War Henry L. Stimson. From the general's autobiography again:

The reason for his objection was that Kyoto was the ancient capital of Japan, a historical city, and one that was of great religious significance to the Japanese. He had visited it when he [Stimson] was Governor General of the Philippines and had been very much impressed by its ancient culture.

Even without Kyoto, though, Groves wanted his two different types of bombs dropped. Indeed, Groves was so afraid that he wouldn't get to test the second bomb design — the problematic Fat Man — that he rushed the second bombing. The first bomb had been dropped on Hiroshima on August 6, 1945. Again quoting from Groves's autobiography (he's referring to William R. Purnell, the navy liaison to the Manhattan Project):

Admiral Purnell and I had often discussed the importance of having the second blow follow the first one quickly, so that the Japanese would not have time to recover their balance. ... Good weather was predicted for the ninth [of August], with bad weather to follow for the next five days. This increased the urgency of having the first Fat Man ready still another day earlier.

The dropping of the second bomb on Japan occurred just three days after the Enola Gay had bombed Hiroshima, even though word of what had happened in that city was only just reaching the national government in Tokyo (telegraph lines were down, there was no television broadcasting back then, radio stations had been destroyed). But, as Groves said, they were deliberately not giving the Japanese government "time to recover their balance." Had they waited, the Japanese might have surrendered before Groves got to drop the implosion bomb on the planned target of Kokura; it was only because of overcast skies there that bomber Bockscar actually dropped its atomic bomb on Nagasaki instead.

As for the Emperor being allowed to retain his throne being the sticking point, it was — right to the very end, even after Nagasaki. From the final chapter of The Making of the Atomic Bomb by Richard Rhodes:

The military leaders of Japan had still not agreed to surrender. The Emperor Hirohito therefore took the extraordinary step of forcing the issue. The resulting surrender offer, delivered through Switzerland, reached Washington on Friday morning, August 10 [1945]. It acknowledged acceptance of the Potsdam Declaration except in one crucial regard: that it "does not comprise any demand which prejudices the prerogatives of His Majesty as a Sovereign Ruler."

In addition to Rhodes's book, another excellent source on this topic is the more-recent (2016) Inferno: The Fall of Japan 1945 by Ronald Henkoff, which states:

The Americans were aware the Japanese had approached the Russians; the Army Signal Corps had long since cracked Japan's diplomatic code and had been intercepting messages from Tokyo since 1940. In all the cables the Americans had decoded, Tokyo's message remained the same: "Unconditional surrender is the only obstacle to peace."

By late May [1945], Truman's top advisers were beginning to grasp that, on this point, the Japanese would not bend.

Secretary of War Stimson, his deputy John McClory, and Acting Secretary of State Joseph Grew argued that if the Japanese knew no harm would come to their emperor, peace might be within reach — and postwar reconstruction might be easier to manage. Hirohito's presence could lend legitimacy to the regime put in place by the Americans.

Admiral William "Bull" Halsey, the tough and outspoken commander of the U.S. Third Fleet, which participated in the American offensive against the Japanese home islands in the final months of the war, publicly stated in 1946 that "the first atomic bomb was an unnecessary experiment." The Japanese, he noted, had "put out a lot of peace feelers through Russia long before" the bomb was used.

Doug Dowd, a Pacific-theater rescue pilot who was slated to take an early part in the invasion of Japan if it had come to that, recently stated that it was clear in the final months of the war that the Japanese "had lost the ability to defend themselves." American planes "met little, and then virtually no resistance," Dowd recalled. He added, "It is well-known [now] that the Japanese were seeking to make a peace agreement well before Hiroshima."

And, as I wrote in The Oppenheimer Alternative, the Japanese did finally get the one concession they wanted — after tens of thousands had died in atomic hellfire in Hiroshima and Nagasaki:

     The Japanese had surrendered two weeks ago, on August 15, 1945, although the formal ceremony, to be held aboard the U.S.S. Missouri, was still several days away. In the end, they'd received the only thing they'd wanted since first making overtures to surrender a year ago, in the summer of 1944: Hirohito, their divine Emperor, would retain the Chrysanthemum Throne. No other solution had ever been possible: the post-war world required a functioning domestic government on the Home Islands. But Truman had continued to insist on unconditional surrender, not making the Hirohito concession until after the two American atomic bombs had been dropped — after the new world order had been set.

Hirohito retained his throne until his death in 1989 at the age of eighty-seven — forty-four years after the end of World War II.

Since the publication on June 2, 2020, of The Oppenheimer Alternative, a few people have asked me, if the above is true, why they hadn't heard this perspective before; some have even go so far as to suggest that this interpretation amounts to revisionist history. It's therefore worth looking at how the issue was officially viewed only shortly after the war. The United States Strategic Bombing Survey, established by Henry L. Stimson, the U.S. Secretary of War, issued its Summary Report (Pacific War), on July 1, 1946, pursuant to a directive by President Harry Truman that the Survey prepare a study "of the effects of all types of air attack in the war against Japan." Here's the Survey's assessment presented as the final paragraph before the report's concluding remarks (emphasis added):

Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Survey's opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945, Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no [American] invasion had been planned or contemplated.

Indeed, as Matthew Penney, Ph.D., a specialist in post-War Japan at Concordia University, said when I laid out the arguments above on Facebook, "Robert — your writing on this subject is excellent. I am a professor of modern Japanese history and everything you have been writing reflects historiographical consensus."

So, since the atomic bombings weren't necessary, why do many American and Japanese history books continue to claim that they were? Well, although it's a truism that history is written by the victors, in this case the victors' claims seem also to have served the purposes of the losers. Writing in the magazine Foreign Policy (in an adapted excerpt from his 2013 book Five Myths About Nuclear Weapons), Ward Wilson, a senior fellow at the British American Security Information Council, says:

Put yourself in the shoes of the emperor ... The war, in short, has been a catastrophe and, worst of all, you've been lying to your people about how bad the situation really is. ... So which would you rather do? ... Issue a statement that says that you miscalculated spectacularly, made repeated mistakes, and did enormous damage to the nation? Or would you rather blame the loss on an amazing scientific breakthrough that no one could have predicted? ... The Bomb was the perfect excuse for having lost the war. No need to apportion blame; no court of enquiry need be held.

Being able to recast Japan as a victimized nation — one that had been unfairly bombed with a cruel and horrifying instrument of war — would help to offset some of the morally repugnant things Japan's military had done. Drawing attention to the atomic bombings helped to paint Japan in a more sympathetic light and deflect support for harsh punishment.

If the Bomb won the war, then the perception of U.S. military power would be enhanced, U.S. diplomatic influence in Asia and around the world would increase, and U.S. security would be strengthened. The $2 billion spent to build it would not have been wasted.

One man was even more responsible than J. Robert Oppenheimer, the title character in The Oppenheimer Alternative, for the American creation of atomic bombs: the Hungarian emigré physicist Leo Szilard. It was Szilard who first conceived of the nuclear chain reaction that makes fission bombs possible and it was Szilard who wrote and urged Albert Einstein to sign the famous letter to Franklin Delano Roosevelt, citing his own recent work and that of Enrico Fermi as the reason the U.S. needed to initiate a atomic-bomb-creation effort. It was also Szilard who came to regret most of all what he'd unleashed on the world, saying in an interview in the August 15, 1960, edition of US News and World Report:

Suppose Germany had developed two bombs before we had any bombs. And suppose Germany had dropped one bomb, say, on Rochester and the other on Buffalo, and then having run out of bombs she would have lost the war. Can anyone doubt that we would then have defined the dropping of atomic bombs on cities as a war crime, and that we would have sentenced the Germans who were guilty of this crime to death at Nuremberg and hanged them?

The final version of Microsoft's Encarta Encyclopedia was dated as 2005 and published in 2004. It contained an excellent essay by historian Gar Alperovitz that is no longer readily available; the online version of Encarta is long gone, too. The essay consists of 2,700 words of considerable wisdom, and I've unearthed it below. I've also highlighted a few key passages like this.

Bombing Hiroshima Was Not Necessary

by Gar Alperovitz

The place to begin is with the top military leaders in the United States during World War II (1939-1945). In his book Mandate for Change, 1953-1956 (1963), Dwight D. Eisenhower, supreme commander of the Allies in Europe during the war, and president of the United States from 1953 to 1961, recalled the day in 1945 when Secretary of War Henry L. Stimson told him an atomic bomb was about to be used against one of Japan's cities:

"During his recitation of the relevant facts, I had been conscious of a feeling of depression and so I voiced to him my 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."

Eisenhower put it bluntly in a 1963 Newsweek interview: "It wasn't necessary to hit them with that awful thing."

William D. Leahy, a conservative five-star admiral who served as President Harry S. Truman's chief of staff and chaired both the World War II U.S. Joint Chiefs of Staff and the Combined American-British Chiefs of Staff, was even more forceful in his book I Was There: The Personal Story of the Chief of Staff to Presidents Roosevelt and Truman (1950):

"... The use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender ....

"... In being the first to use it, we ... 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."

President Richard M. Nixon (1969-1973) recalled in a 1985 Time article how the supreme commander in the Pacific felt about the atomic bomb:

"[General Douglas] MacArthur once spoke to me very eloquently about it, pacing the floor of his apartment in the Waldorf. He thought it a tragedy that the Bomb was ever exploded. MacArthur believed that the same restrictions ought to apply to atomic weapons as to conventional weapons, that the military objective should always be limited damage to noncombatants ....

"MacArthur, you see, was a soldier. He believed in using force only against military targets, and that is why the nuclear thing turned him off."

The list of World War II military leaders who felt the use of the atomic bomb was unnecessary is very long. It includes men such as General Henry H. "Hap" Arnold, commander of the U.S. Army Air Forces; Admiral Chester W. Nimitz, commander in chief of the Pacific Fleet; Admiral William Halsey, commander of the Third Fleet; Curtis LeMay, Army Air Force major general and commander of the 21st Bomber Command; and many others. We also know that General George C. Marshall, chief of staff of the U.S. Army, who shortly before his death in 1959 gave interviews defending the decision, expressed very different views inside the government before the bomb was used. A top secret memorandum from 1945, dated two months before Hiroshima, records that:

"He [Marshall] thought these weapons might first be used against straight military objectives such as a large naval installation and then if no complete result was derived from the effect of that, he thought we ought to designate a number of large manufacturing areas from which the people would be warned to leave — telling the Japanese that we intend to destroy such centers .... Every effort should be made to keep our record of warning clear. We must offset by such warning methods the opprobrium which might follow from an ill-considered employment of such force."

One of the reasons so many American military leaders felt as they did was that Japan was already essentially defeated and everyone knew it. Japan had virtually no navy, almost no air force, very little fuel or ammunition, and few of the basic supplies required to make war against the most powerful nation in the world. Furthermore, U.S. intelligence experts had broken Japanese diplomatic codes early in the war and were secretly listening to all Japanese cable traffic between Tokyo and its embassies around the world. It was clear that Japan was searching for a way to somehow end the war.

An illuminating way to gain perspective on the decision to use the atomic bomb is to go back to April 12, 1945, when President Franklin D. Roosevelt died and a new president, Harry S. Truman, took office. At this time, and for the next three months, the atomic bomb was merely a scientist's theory. Although it was hoped that the new weapon would work, no one could say for sure that it would because it had never been tested. And certainly no one could count on a theoretical weapon to end the war.

For this reason, all planning during the spring and summer of 1945 had to be based on the assumption that the theory might remain a theory and never become a bomb. Accordingly, beginning as early as April 1945, top officials offered three key points of advice.

First, many felt there was a very good chance Japan would surrender if the United States merely offered some modest face-saving concessions, assuring the Japanese that their emperor, Hirohito, whom they regarded as a god, would not be removed from office or tried as a war criminal. In general, letting him stay on without any power, in a manner akin to the king of England, seemed extremely important.

Second, even if this did not end the war as many believed it would, U.S. intelligence experts advised that combining assurances for the emperor with a massive new military shock would almost certainly do so. That shock would be a declaration of war against Japan by the Union of Soviet Socialist Republics (USSR), followed by a Red Army attack on Manchuria, a region of China that bordered the USSR and that had been seized by Japan. The declaration was expected in early August. The Soviet Union, fighting for its life against Germany, had maintained neutrality for most of the Pacific war, and U.S. diplomats had worked hard to secure a Soviet pledge to join the war against Japan three months after Germany was defeated.

Once Germany surrendered in May 1945, both Britain and the United States concentrated their combined military might against Japan, which was already on its last legs. Intelligence experts believed the Red Army's attack would force Japan to realize the war must end. Even before the end of April 1945 a secret intelligence report judged that increasing "numbers of informed Japanese, both military and civilian, already realize the inevitability of absolute defeat."

"The increasing effects of air-sea blockade, the progressive and cumulative devastation wrought by strategic bombing, and the collapse of Germany (with its implications regarding redeployment) should make this realization widespread within the year," the report said.

But this was without the Russians. The report went on to a much stronger judgment: "The entry of the USSR into the war would, together with the foregoing factors, convince most Japanese at once of the inevitability of complete defeat."

Before the atomic bomb was tested, President Truman traveled to the Potsdam Conference in Germany to meet Soviet premier Joseph Stalin precisely because he wanted to be sure to get the Russians into the war. As he later wrote: "If the test [of the atomic bomb] should fail, then it would be even more important to us to bring about a surrender before we had to make a physical conquest of Japan."

The third point of advice given by top officials during the summer of 1945 was similar to, but slightly different from, the first point. Many U.S. experts believed Japan was likely to surrender if assurances were given about the emperor, and far more likely to surrender if these assurances were combined with a Red Army attack. But virtually all agreed that Japan was highly unlikely to surrender if the United States did not make it clear that the emperor would not be harmed.

A few key dates help clarify how the summer months unfolded. First, it is important to understand that the full invasion of Japan could not have taken place, and was not even planned for, until the spring of 1946. Moreover, the first step toward the full invasion — an initial landing on the island of Kyushu — could not take place until November 1945. In short, there was plenty of time to test advice that the war could likely be ended by a combination of assurances for the emperor and the Red Army attack expected in early August.

The next date is July 16, when the atomic bomb was successfully tested in New Mexico. After this test, the alternatives proposed to gain Japan's surrender during the early summer were abandoned. Instead, the first atomic bomb was dropped on Hiroshima on August 6 and the second bomb was dropped on Nagasaki on August 9 — just before the date the Russians had originally been expected to attack. In fact, U.S. leaders now tried to stall the Russian declaration of war. The November landing date at Kyushu was still almost three months off.

After the war a top secret internal War Department study concurred with the intelligence judgments offered in April: "The Japanese leaders had decided to surrender and were merely looking for sufficient pretext to convince the die-hard Army Group that Japan had lost the war and must capitulate to the Allies."

The study judged that Russia's early August entry into the war "would almost certainly have furnished this pretext, and would have been sufficient to convince all responsible leaders that surrender was unavoidable." It also concluded that an initial November landing had been only a "remote" possibility and that the full invasion of Japan in the spring of 1946 would not have occurred.

Some historians believe that it was simply assumed that the bomb would be used once it was ready, or that there were political reasons why the terms given the emperor could not be changed. However, evidence discovered in recent years, together with intercepted Japanese cables, makes it clear that this was not the view at the top level of the U.S. government. For instance, early in August 1945, before the bombs were dropped, the diary of Walter Brown, an assistant to the secretary of state, records the following discussion of the latest intelligence information by the president, Admiral Leahy, and "JFB" (Secretary of State James F. Byrnes):

"Aboard Augusta/President, Leahy, JFB agrred [sic] Japas [sic] looking for peace. (Leahy had another report from Pacific) President afraid they will sue for peace through Russia instead of some country like Sweden."

Some historians who agree that an invasion was highly unlikely have attempted to defend the use of the atomic bomb for other reasons. They argue that even though the war would almost certainly have ended before November, fighting was still going on and American lives were being lost. Accordingly, even if the atomic bombs were not needed to prevent either the November landing or the full 1946 invasion, using them may have saved lives that otherwise would have been lost during the period when a surrender was being arranged without using the bombs. How many lives, of course, is impossible to know. Combat was reduced at this point, and the number of days, weeks, or months involved is highly speculative.

So far as we know, top U.S. leaders did not make this argument, although many later tried to defend the use of the atomic bomb by suggesting that it saved perhaps one million American men, a figure that has been shown to have no factual basis. Moreover, if saving every possible life was the overriding consideration, it is difficult to explain why, against the advice of the U.S. military, American leaders made surrender so much more difficult by putting off assurances to the emperor and by attempting to delay the Russian attack after the bomb test was successful.

Others have not only challenged the argument that the atomic bomb may have saved a small number of lives, but have suggested that it actually may have cost many thousands of American and Japanese lives. One of those who implied as much was Secretary of War Stimson, the Cabinet member responsible for building the atomic bomb.

After the war, Stimson returned to the understanding on all sides that if assurances for the Japanese emperor were not given, it was always clear that Japan would likely fight to the last man and the war would continue indefinitely. It was quite possible, he later wrote, that "history might find that the United States, by its delay in stating its position, had prolonged the war."

Stimson, along with virtually every other top U.S. official involved, had urged that such assurances be given early enough in the summer to allow Japan time to make its decisions. However, on the advice of Secretary of State Byrnes, President Truman decided not to do this. Indeed, the assurances regarding Hirohito that were already written into the Potsdam Declaration, which warned Japan to surrender, were deliberately removed just before the bomb was used. This made it all but inevitable that the war would continue and that Japan would not surrender.

Japan was not given assurances for the emperor early on because it had been decided to wait for the test of the atomic bomb. Had there been no bomb, there would almost certainly have been far less delay in offering these assurances. And then, as Martin Sherwin, a historian at Tufts University in Medford, Massachusetts, has observed, the war might well have ended much earlier in the summer and "many more American soldiers and Japanese of all types might have had the opportunity to grow old."

We will never know, of course, whether the war could have been ended earlier had it not been decided to delay offering assurances. However, it seems increasingly clear to many historians that, as so many top World War II generals and admirals believed, using the atomic bomb was not militarily necessary. Moreover, even after two atomic bombs were used, Japan did not surrender until the assurances for the emperor were finally given in a U.S. message implicitly accepting this fundamental condition.

Many historians now also understand that diplomatic considerations regarding the Soviet Union figured importantly in the decision to use the atomic bomb because it offered an alternative to a Russian attack. Indeed, once the successful atomic test occurred, Secretary of State Byrnes and others reversed course entirely and tried to end the war before the Russians got in. It is also quite clear that many top U.S. officials saw the bomb as a powerful "big stick" to wave in diplomacy against the Russians. The precise role such diplomatic, as opposed to military, factors played in the decision is still not entirely clear, but many experts recognize their importance.

Very few historians believe the bombing of Nagasaki, the second city, can be justified on any grounds. Moreover, even those who defend the use of the atomic bomb in general often avoid the central point made by General Marshall that if a bomb were used, it should first be used on a strictly military target such as a naval base. Then, if such a bombing did not produce the desired results, a clear warning should be given so civilians could be evacuated from the cities before another bombing. And only if this did not work, should an inhabited city be bombed.

None of this occurred, of course. Neither Hiroshima nor Nagasaki were important military targets. The bombs were used without explicit warning and targeted in a manner designed to create shock by destroying as many workers' homes as possible. It is conceivable, given all the facts we now have in our possession, that some strictly military use and targeting of the bomb, as Marshall urged, can be defended. But there can be no legitimate military or moral defense of the decision to use the atomic bomb mainly against the women, children, and elderly civilians who were left behind in Hiroshima and Nagasaki when most of the young men had gone to war.

Gar Alperovitz is Lionel R. Bauman Professor of Political Economy in the department of government and politics at the University of Maryland, College Park. He is the author of The Decision to Use the Atomic Bomb (1995) and Atomic Diplomacy: Hiroshima and Potsdam (1965).

More Good Reading

More about The Oppenheimer Alternative
Robert J. Sawyer's awards and honors
What's a Rob Sawyer novel like?
Review index

My Very Occasional Newsletter