On the night of March 9-10, 1945, the 21st Bomber Command, led by U.S. Gen. Curtis LeMay, carried out an attack with incendiary bombs in central Tokyo, the world’s most densely populated urban area. At least 83,000 people died that night, perhaps more, as thousands were reduced to ash. That week, Japanese Emperor Hirohito told his close advisors that he wanted to find a way to end the war before it imposed more destruction on his people.
This article is adapted from Rain of Ruin: Tokyo, Hiroshima, and the Surrender of Japan by Richard Overy (W. W. Norton & Company, 224 pp., $29.99, March 2025).
Eighty years later, there remains a strong popular conviction that Japan surrendered in August 1945, ending the Pacific Theater of World War II, because of the two atomic bombs that the United States dropped on Hiroshima and Nagasaki. The connection has always seemed clear: A few days after the bombs, which killed at least 200,000 people, the Japanese government accepted the Allied ultimatum and terminated the war. Yet from what historians know now, this connection is anything but straightforward.
The focus on the atomic bombs overlooks the impact of conventional bombing on Japan’s cities. It also overlooks the effort by Hirohito and some of his closest advisors to find a way of ending the conflict that went back to at least March 1945, when Tokyo suffered the worst air raid of the whole war. In a period where nuclear threats are thrown about almost casually, looking back at this history is a sobering exercise—and it serves as a reminder that the ultimate weapon, once widely considered a necessary evil, should never be unleashed again.
What followed the bombing of Tokyo was a complicated political process, little understood by Washington. There was a sharp division between Japan’s army leaders and politicians over how to respond to the growing crisis. The military wanted to prepare for a final apocalyptic battle to defend the kokutai, or “sacred homeland,” and mobilize the population as a civilian militia to help repel the U.S. invasion. Meanwhile, a “peace faction” emerged among the political elite, which wanted to find a way to terminate the war as soon as possible. (The word “surrender” was never used, and indeed was not allowed to be spoken in front of the emperor, though termination amounted to much the same thing.) The two sides were united only in their desire to ensure that the emperor would retain his throne after the war ended.
Hirohito became an advocate for the peace faction through the late spring and summer of 1945, impatiently prodding his ministers to find a way. What he was not supposed to do, according to the constitution, was make the decision himself. The cabinet and Supreme War Council were supposed to reach a unanimous decision on policy, which the emperor would then ratify. Only in an emergency could he make what was called a seidan, or “sacred decision,” to overcome division.
The outcome was a stalemate as the peace faction searched for a solution. In the meantime, LeMay’s bombing campaign continued remorselessly to destroy Japan’s cities and smaller towns. By August, nearly 60 percent of Japan’s urban areas had been burned down, 10 million people had evacuated to the countryside, and the country’s food supply—already much reduced because of the naval blockade—was further undermined by the bombings.
Japan faced a growing social crisis that summer amid the difficulty of coping with mass evacuations and the growing apathy and exhaustion of the workforce. Problems at home induced Navy Minister Yonai Mitsumasa to argue against his colleagues and support an immediate peace. Japan’s elite was profoundly fearful of communism, which the secret police had harshly repressed in the 1930s. The social crisis raised again for them the specter of social revolution and the prospect that Japan’s war effort might collapse like Russia’s in 1917. The more the bombing went on, the more likely it seemed that something would snap.
In June, Hirohito insisted that a way to end the war be found. His advisors, who wanted to avoid a possible army coup, suggested asking the Soviet Union to intercede with the Allies to begin the peace process. This was a misguided solution. While the Allies negotiated the future of Europe at the Potsdam Conference in July 1945, the emperor and the peace faction waited for the response from Moscow. By this time, the atomic bombs were ready, and U.S. War Department had already reached an agreement to drop them on the center of a city, complementing LeMay’s city-busting strategy. On July 26, the United States, Britain, and China issued the Potsdam Declaration, an ultimatum calling for Japan to surrender or face “prompt and utter destruction.”
Although subsequent history has seen the atomic bombing as distinct from the urban bombing campaign, it was in effect a continuation. U.S. President Harry S. Truman hoped that the shock of such a bomb would push Japan to accept surrender, but U.S. military leaders were less convinced and continued planning for the operations to invade the Japanese home islands.
By the bombing of Hiroshima on Aug. 6, the emperor had already informed his advisors that the Potsdam Declaration was acceptable in principle, and discussion began over how to proceed. News arrived in Tokyo about Hiroshima, but there was no certainty about what had happened, and formal investigation to ascertain the facts of the attack only began on Aug. 8. It was not until Aug. 10 that a report sent to Tokyo confirmed that the bomb was either an atomic bomb or another bomb of extraordinary power.
The reaction to Hiroshima was neither immediate nor decisive. Instead, in the early hours of Aug. 9, news arrived that the Soviet Union was at war with Japan. The Red Army swept aside Japanese resistance in Manchuria in a matter of days. The shock of the news finally prompted the cabinet to act. The greatest fear was that the Soviets might arrive in Japan before the Americans and pursue the same kind of solution they had imposed on Eastern Europe, with annexations, police terror, and a communist version of democracy.
News of the Nagasaki bomb did not arrive until later that morning, in the middle of a long Supreme War Council meeting to discuss acceptance of the ultimatum. It made little difference, and confirmation about the nature of the bomb was reported only by the time Japan had already capitulated.
The deadlock that had persisted over the summer reemerged during the meetings on Aug. 9. Neither side wanted to reject the Potsdam Declaration outright, but the army wanted conditions, while the peace faction only wanted assurance that Hirohito would remain in place. Finally, it was decided that the logjam should be resolved by the emperor himself. Late that night, Hirohito made his sacred decision: He made clear that the ultimatum had to be accepted. The cabinet met and agreed upon the emperor’s request. The United States was notified the following day that the declaration was accepted, provided the emperor could retain his prerogatives.
There followed four confusing days in which the U.S. State Department debated what was meant by “prerogatives” before Secretary of State James F. Byrnes replied that the emperor would be subject to authority of the Allied supreme commander, in this case Gen. Douglas MacArthur. The U.S. incendiary bombing continued unabated, to Hirohito’s acute distress. The Byrnes reply prompted two more days of arguing between the army and the politicians while the emperor explained his decision to the members of the royal family and the senior advisors to the throne.
The arguments were once again stifled by Hirohito, who summoned an imperial conference on the morning of Aug. 14, where he told the assembled military and political leaders that the war had to end at once to avert further suffering for his people and that they all had to agree with him. The imperial rescript ending the war was broadcast the following morning, though not before a cabal of young officers had briefly taken over the imperial palace in the hope of finding the recording of the broadcast and possibly murdering the members of the peace faction. The coup was quashed by their commanding general early on Aug. 15.
This second seidan sealed Japan’s capitulation, though it was three weeks before a formal surrender was signed in Tokyo Bay aboard the battleship Missouri. Fear of social crisis, distress at the continuous urban bombing, and anxiety about whether Joseph Stalin’s forces would get to Japan first all played a part in the final decision. The military leadership accepted the emperor’s choice with reluctance. It is likely that they really understood that Japan had little prospect of defending itself against the separate Allied threats: U.S. and Soviet. Civilian politicians, meanwhile, wanted the war to end so that Japan could rebuild its broken cities and battered industry before social crisis erupted.
In all this final drama over the summer months, the atomic bombs played a much less significant role than the popular image of Japan’s surrender suggests. The bombs were “an additional factor,” according to the prime minister at the time, Suzuki Kantaro. Too little was understood about what the bombs were, and the Japanese army soon began to argue that they were survivable, like the aftermath of a firebombing.
Despite Truman’s optimism, even U.S. military leaders could not be sure that the bombs would have an immediate effect, and the Air Force planned for a more extensive nuclear conflict. Early plans in May had called for two bombs on Hiroshima, four on Kyoto, and two on Niigata. Kyoto was removed as a target, but in the second week of August, following Hiroshima, six more cities were selected as targets for the bombs set to come off the production line by December. Truman suspended the atomic attacks on Aug. 10, but because the Japanese seemed to dither over acceptance of the ultimatum, he began to consider renewing the campaign.
Even postwar reports by the British and U.S. investigation teams sent to Japan in August and September 1945 suggested that the bombs had not been the decisive factor but rather helped to accelerate a process already under way. Still, their findings on the effects of the atomic bombs were sobering. They compared the damage they found with what might happen to a British or U.S. city. The British calculated that a similar bomb would destroy and damage up to 115,000 houses and kill 50,000 people; U.S. calculations found that in major cities, all the buildings up to a mile and a half from the epicenter of the bomb would be destroyed. The British report concluded with characteristic understatement that defense against a nuclear attack “represented a formidable problem.” Neither country in the end has ever had to cope with this reality.
The atomic bombing was a horrendous experience for those who suffered it, and yet the two bombs might not have been necessary for Allied victory at all. Bombing always produces widespread civilian losses, as evident today in Gaza and Ukraine as it was in Japan in 1945. The last thing the world needs is for states to turn to modern thermonuclear bombs, which would achieve a level of destruction well beyond Hiroshima or Nagasaki. Everyone must hope that the first use of nuclear weapons will remain the last.
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