The moral indictment of the bombings works from a grossly upside-down portrait of the number and identity of the war’s victims.

J ournalists have identified the use of atomic bombs against Japan in August 1945 as the greatest story of the 20th century. Beginning in the 1960s, a body of critical work among historians appeared challenging the early narratives that had validated the use of these weapons. (I reject the term “revisionist,” as any historian with new facts and arguments engages in revisionism. “Critical” is a more accurate term for these arguments.) The import of this critical work vaulted over the immediate issue into a searing condemnation of the moral fabric of all American history. These historians condemned the atomic bombings as stunningly singular immoral acts. Some used the bombings as grounds to forever preclude any claim of righteousness or greatness to Americans. The controversy burst outside the cloisters of academia into the public and has become an enduring fault line.

The Moral Calculus

The controversy erupted in a particularly contentious passage of 20th-century history. Most fundamentally, this moral indictment works from a grossly upside-down portrait of the number and identity of the war’s victims. Further, its factual premises were undermined with the release of extensive new evidence from the 1990s, notably in the U.S. and Japan.

The first basic point is that this war was not merely the “Pacific War.” That narrow lens treats events as though they were bound between December 1941 and August 1945. It foregrounds the conflict between the United States and Japan across the Pacific. It recognizes only a handful of additional participants: the Philippines, Australia, Pacific Islanders, and New Zealanders. The actual conflict properly identified is the Asia-Pacific War. It commenced with Japan’s assault on China in July 1937 and only ended officially 97 months later — although fighting continued “postwar” in Asia for years. Japan enormously expanded the war starting in December 1941 to reach India on the west and pierce far into the Pacific Ocean on the east.

The Asia-Pacific War killed 25 million human beings, by conservative count. Of these, about 6 million were military personnel, including about 3 million Chinese and 2 million Japanese. There were 19 million dead civilians — or three dead civilians for every combatant death. A reasonable range of European war casualties reaches the vicinity of 37–48 million, but the ratio of civilians to combatants does not rise above two to one.

Of the Asia-Pacific War civilian dead, 1–1.2 million were Japanese, including about 210,000 immediate and latent deaths at Hiroshima and Nagasaki. This leaves about 18 million dead civilians who were not Japanese. Extremely few of these were white. The 18 million comprises 12 million Chinese, 2.7 million Indonesians, 1 million Vietnamese, and about 2.3 million spread among other peoples of Asia and the Pacific. Framed another way, Japanese civilian deaths form about 6 percent of all civilian deaths, and atomic-bombing-related deaths make up less than 2 percent of all civilian deaths.

If 25 percent of the dead Chinese were children, that means one Chinese child died for every Japanese combatant and civilian who perished in the war. Combining the Indonesians and the Vietnamese, their civilian deaths exceed the total of Japanese combatant and civilian deaths. By the numbers, across China and all the other areas subjugated in Japan’s empire from December 1941 to August 1945, about 250,000 non-Japanese civilians died every month for 45 months, or the equivalent in population of more than 45 Hiroshimas and Nagasakis. Between April and August 1945, a further million Vietnamese, or about 200,000 each month, starved to death.

But who was a “civilian” in Japan? Japan’s leaders in March 1945 issued orders that all Japanese males 15 to 60 and all Japanese women 17 to 40 became part of “Volunteer Patriotic Units.” They received minimal training and no distinctive uniforms that would clearly separate their status as combatants from the civilian population. This confirmed American fears of a “fanatically hostile population” to confront an invasion of Japan. Thus, a major fraction of the population in every Japanese city were combatants, including Hiroshima and Nagasaki. The critical literature ignores this reality. Nor does it address any moral responsibility for Japan’s leaders for mingling combatants and noncombatants.

Getting the moral calculus correct on this anniversary is by far the most important task on the path to understand and judge how the Asia-Pacific War ended. But this also encompasses important factual issues.

Invasion of Japan

An invasion of the Japanese home islands was a highly contentious component of American strategy to achieve unconditional surrender. The U.S. Army believed that the critical issue was time. The American people would lose patience to sustain the war if the war became protracted. The Army saw the quickest path to Japanese surrender to be an invasion of the home islands. Ominously, after three years of the Japanese “no surrender” record, the Army further believed that it might not be possible to obtain an organized Japanese surrender. An invasion would position the U.S. to systematically subdue the holdouts.

The U.S. Navy believed that the critical issue was casualties. Huge casualties would prompt public demand for negotiated peace. The Navy looked to end the war by bombardment by air and sea and a blockade to starve to death Japanese civilians by the millions — based on the norm-breaking path set against Germany in World War I. This strategy would minimize U.S. casualties, but the timeline to a Japanese surrender by this strategy was unknowable.

The Army secured President Harry S. Truman’s reluctant authorization in June 1945 for an initial invasion of Kyūshū, the southernmost Japanese home island starting on November 1, 1945. Then, in July and into August, radio intelligence stunningly unmasked the Japanese preparation to turn southern Kyūshū into a huge strategic ambush. The Japanese exactly anticipated southern Kyūshū as a target, down to the specific landing areas. The radio intelligence showed that massive Japanese forces packed the landing areas, vastly outnumbering the American units that would actually engage the Japanese defenders, not perform support duties.

Admiral Ernest J. King, the senior American naval officer, fiercely opposed any invasion. But he had bided his time, waiting for a showdown. The radio-intelligence picture by early August demonstrated that the facts were on his side. King moved on August 9, the same day as the Nagasaki bomb, to trigger a showdown to cancel the Kyūshū landing (or any invasion). But Japan surrendered before this played out. This story remained unknown, because of secrecy, well into the 1990s. This rendered pointless the contentious debate on potential invasion casualties, since the belatedly revealed reality was far worse than the earlier projection contemplated. King’s action demonstrated just how dark the invasion strategy looked in August 1945. If the planned invasion then looked unthinkable, no plausible American president would have failed to authorize use of atomic weapons in August 1945.

Belated radio-intelligence disclosures also cast new light on the feeble Japanese diplomatic initiatives in 1945. Japan’s uniformed leaders confidently expected Operation Ketsugō — the plan for defeating an American invasion — to provide the indispensable bargaining room for a negotiated peace. To the very end, they believed that there was no need to specify the terms they could obtain until Ketsugō shaped the range of possibilities.

Hirohito initially endorsed Ketsugō. But by June, disturbing reports reached him from inspectors he had dispatched about the lagging preparations. He and others became increasingly uneasy about the declining state of civilian morale. He met with the government’s inner cabinet and urged exploration of diplomacy to end the war. Direct negotiation with the U.S. was anathema to the military, so they authorized an attempted mediation by the Soviet Union, which was not yet at war with Japan.

Although at first the initiative prompted American hopes that this might signal an end to the war, and this generated much postwar ink to be spilled, ultimately the effort went nowhere. Americans followed it closely because of their complete mastery of Japanese diplomatic codes. The initiative ran between the Japanese ambassador in Moscow, Naotake Satō, and Foreign Minister Shigenori Tōgō in Tokyo. Satō’s exchanges with Tōgō read like a searing cross-examination on behalf of the Truman administration. Tōgō demanded that Tokyo provide him with inducements to secure Soviet mediation. Satō dismissed Tōgō’s flowery nothings as “pretty little phrases devoid all connection with reality.”

Then Satō told Tōgō that the initiative’s prospects depended on Tokyo’s providing a set of terms for ending the war. Tōgō could not provide terms because the military, which dominated Japanese government, refused to even discuss them. Utterly frustrated, Satō replied that the best Japan could hope for was unconditional surrender save for retention of the Imperial House, the country’s reigning dynasty. Tōgō rejected this — in the name of the government. The elite cadre of analysts who prepared the daily news sheet of intercept disclosures for top American leaders took pains to highlight the rejection by Tōgō of unconditional surrender even if terms included the retention of the Imperial House.

How Did the War End?

The towering library on why Japan surrendered could now fill a gigantic warehouse. My approach stems from decades of experience with witnesses and documents. That experience taught me to look first and foremost at the contemporary evidence as the most reliable guide, before witness testimony and the content of documents are altered by the manifold defects of human memory or by later agendas. The more distant the evidence appears after the event, the greater the caution it earns.

A close aide recorded on August 12 the reflections of Admiral Yonai Mitsumasa, Japan’s navy minister and part of the inner cabinet of the government: “The atomic bombs and Soviet entry into the war are, in a sense, gifts from the gods. This way we don’t have to say that we have quit the war because of domestic circumstances.”

Yonai’s trenchant contemporary assessment confides that the atomic bombs and Soviet intervention served vitally to mask the real reason for Japan’s surrender: the “domestic circumstances.” This was a euphemism for the fear that the Japanese people were reaching a revolutionary state that would not only topple Emperor Hirohito from the throne but also smash the imperial institution itself. The increasingly dire food shortages that resulted from the American blockade and the weather-induced collapse of the 1945 rice harvest, as well as the ravages of American bombing, produced the “domestic situation.”

When Yonai spoke, Japan’s leaders were deadlocked. The Supreme Council for Direction of the War (known as the “Big Six”) legally controlled Japan’s destiny. They were part of Prime Minister Admiral Kantarō Suzuki’s government. Only Foreign Minister Tōgō was a civilian. Besides Suzuki and Tōgō, the Big Six included Navy Minister Admiral Yonai, Army Minister General Korechika Anami, Chief of the Naval General Staff Admiral Soemu Toyoda, and Chief of the Army General Staff General Yoshijirō Umezu. Emperor Hirohito served outwardly as Japan’s supreme ruler and was divine. He was a presider, not a decider. Since becoming emperor in 1925, just once had Hirohito commanded the government to obey his orders. This was in February 1936, when an attempted coup d’état in Tokyo murdered members of his inner orbit. Hirohito donned his field marshal’s uniform and commanded the dithering government to suppress the coup immediately. That singular moment, among almost 20 years of inaction, gave no hopeful prospect of Hirohito’s directly ordering an end to the war — unless something extraordinary happened.

The deadlock began to break when a uranium-type atomic bomb devastated Hiroshima, on August 6. Before President Truman announced the atomic bombing, Tokyo only knew that something horrific had happened to Hiroshima. An important fact typically missed is that the Big Six did not seek expert opinion from scientists about the significance of an atomic bomb. Japan had an atomic-bomb program that failed to produce a weapon but yielded one critical product. This was the understanding that creating an atomic bomb hinged on the weapon’s fuel, fissionable material. Japan’s program revealed that producing fissionable material was a protracted and enormously resource-intensive process far beyond Japan’s capability. The Imperial Army insisted that there must first be an investigation to confirm the Americans’ claim. The Imperial Navy argued that the Americans may indeed have one atomic bomb, used at Hiroshima, but that they could not be as powerful as to have more than one, or that, even if they were, international pressure perhaps would prevent them from dropping more. Outwardly, the Big Six seemed unimpressed, but their reasoning showed that they were discounting not the unprecedented power of an atomic bomb but whether the U.S. had an arsenal of such weapons.

The Hiroshima bomb did hit one other target. On the afternoon of August 8, Hirohito met with Foreign Minister Tōgō. This was after Hiroshima, with the threat of the “domestic situation” escalating but before Soviet entry. Hirohito told the foreign minister that the war must now end. The Big Six put off Tōgō’s efforts to get them to meet. During the night of August 8, the Soviet Union declared war on Japan, and a 1.5-million-man Soviet invasion force attacked Manchuria.

News of the Soviet declaration of war and the attack reached Tokyo by morning. Imperial Army leaders knew that the Kwantung Army in Manchuria had been reduced to a pitiful state. It could only delay the Soviets. The vice war minister, General Torashirō Kawabe, rated Soviet intervention as a greater shock than Hiroshima. But he proposed to War Minister Anami that the army should discard the last vestige of civilian government and henceforth rule Japan from Imperial Headquarters. We, very fortunately, do not know where this very frightening alternative course might have left Japan.

The Big Six met on the morning of August 9. Prime Minister Suzuki declared that the atomic bomb and the Soviet invasion meant that the war could not go on. During the meeting, news came of the atomic bombing of Nagasaki. Two atomic bombings in three days implied that the U.S. had an arsenal of such weapons. The Big Six split. Suzuki, Tōgō, and Yonai believed that the war should end on the terms of the Potsdam Declaration of July 25 (of which more shortly), modified only by continuance of the imperial institution. Anami, Umezu, and Toyoda insisted on three more terms: (1) Japanese self-disarmament, (2) Japan’s ability to conduct any “war crimes” trials, and (3) no occupation of Japan. These clearly would permit survival and later revival of the old militarist order that had produced the war that killed 25 million humans.

This division of the Big Six continued through the day, but it also offered the unprecedented opportunity for Emperor Hirohito to break the deadlock. He did exactly this at an Imperial Conference in his presence in the early hours of August 10. He cited three reasons for his decision: (1) loss of faith in Ketsugō, (2) the conventional (and by some accounts the atomic) bombing, and (3) the “domestic situation.” He did not mention Soviet intervention. Indeed, from August 8 to the final surrender announcement on August 14, he mentioned Soviet intervention just once in conjunction with the atomic bombs. Moreover, a week after the surrender he sent to his son, the crown prince, a letter that he never expected to be made public. He explained the surrender on the basis that “our people” regarded the British and the Americans too lightly and exalted in their superior “fighting spirit” and ignored science, an obvious euphemism about the atomic bombs. He consciously made no reference to Soviet intervention.

Japan dispatched a diplomatic message through Swedish intermediaries on August 10, conveying Tōgō’s “one condition” offer of surrender. But it housed a poison pill. This was a demand that the emperor rule as superior to the occupation commander. This would give the emperor veto power over occupation reforms.

Fortunately, U.S. State Department officers recognized this ploy despite its arcane and deceptive language. The U.S. response became known as the “Byrnes note,” after Secretary of State James Byrnes. It emphatically stated that the emperor would be subordinate to the occupation commander. It repeated language from the Potsdam Proclamation to convey that, once it was clear Japan was peaceful and democratic, the ultimate form of government would be chosen by the freely expressed will of the Japanese people.

War Minister Anami and his allies in the Big Six found this unacceptable because it did not explicitly confirm that the imperial institution would continue. For four days the internal debate continued. On August 13, Hirohito conferred with Kōichi Kido, his chief confidant. Kido’s contemporary diary entry shows that the emperor stated that even if the Americans were willing to retain him as emperor, if the Japanese people did not support this, the institution would fall. Thus, he was willing to submit his status to the Japanese people. Here, 19 days later, Hirohito is saying the terms of the Potsdam Proclamation were satisfactory. Those terms left open the prospect of both a continuance of the imperial institution and even Hirohito’s rule. With this comment, Hirohito showed that he regarded the support of the Japanese people more important to the continuance of the imperial institution than the threat of its abolition by the U.S. or the Soviets.

At a second Imperial Conference, on August 14, the Big Six dutifully recounted their divisions over the Byrnes note. At the end, Hirohito reaffirmed his decision to end the war. That night, Hirohito recorded his national address announcing the end of the war. Radical middle-grade Imperial Army officers staged a coup. They killed the commander of the Imperial Guards, entered the emperor’s compound, but did not find the hidden record with Hirohito’s address. The leaders committed suicide the next morning.

On August 15, the Japanese people gathered to listen for the first time to the voice of the emperor. In his speech, instead of the word for surrender, the emperor used a tortured circumlocution: “The war situation has not developed necessarily to Japan’s advantage, while the general trends of the world have all turned against her interest.” He went on to explain that “the enemy has begun to employ a new and most cruel bomb, the power of which to do damage is indeed incalculable, taking the toll of many innocent lives.” Ending the war, therefore, would prevent “the total extinction of human civilization.”

At a Hiroshima hospital overflowing with patients suffering horrific injuries from the atomic bomb, Dr. Michihiko Hachiya was surprised when the emperor announced that the war had ended. But shocking were the multiple voices from his patients, many dying, “shouting for the war to continue.”

Admiral Yonai later confessed that he experienced extreme anxiety for four days after the emperor’s broadcast over whether the surrender would hold. War Minister Anami, who had the power to stop the surrender, chose not to use it, in deference to Hirohito. Anami committed suicide wearing a shirt given to him by the emperor. The senior Japanese commanders in China and in the Southern Area (Southeast Asia and part of the Pacific), who led about a third of all of Japan’s armed forces, immediately announced that they would not comply with the emperor’s order. Hirohito dispatched imperial princes who convinced them to obey.

Slowly, the surrender took hold. The formal surrender occurred on the battleship Missouri on September 2. Hiroshima and Nagasaki survivors continued to die, as did a far larger number of Asian civilians who had suffered the impact of Japanese conquest, as well as 300,000–400,000 Japanese civilians who fell into Soviet captivity.