It’s commonly said (in America anyway) that dropping atomic bombs on Hiroshima and Nagasaki in August 1945 saved the lives of thousands, even hundreds of thousands, of American soldiers, since our destruction of Hiroshima and Nagasaki convinced Japan to surrender, and that meant we didn’t have to invade Japan.

According to Hiroshima Nagasaki: The Real Story of the Atomic Bombings and Their Aftermath, by the Australian historian Paul Ham, that’s not how historians view those events. I haven’t read the book and don’t know if I ever will (it’s 500 pages plus notes), but a review at the Los Angeles Review of Books site by Rutgers University historian H. Bruce Franklin strongly suggests that the book is worth reading if you want to understand what really happened at the end of World War 2.

Franklin summarizes the consensus view among historians:

…the atomic bombs were not necessary and did not significantly shorten the war, … no invasion of Japan prior to November was even contemplated, … the surrender of Japan was already imminent in July, … the Soviet entry into the war on August 9 was a major factor in the Japanese surrender, and therefore the atomic bombs probably saved no American lives at all.

He also summarizes Japan’s military situation in mid-July 1945:

… Japan had lost all its bases in the Pacific, and fleets of B-29 Superfortresses had reduced all but four Japanese cities to desolate ruins and smoking ashes while carrier-based navy bombers were systematically destroying its military facilities. Japan had no viable defenses against these aerial assaults. Japan’s only remaining army of any significance was isolated in Manchuria and Korea, and could not be brought home to defend the homeland because US ships were blockading Japan and shelling its coastal regions with impunity.

The most surprising aspect of this story (speaking as someone educated in the United States) is the role of the Soviet Union in ending the war with Japan. The Russians had agreed months before to enter the war by August. The Red Army had more than one million men in position by July. On July 17th, President Truman wrote in his diary that the war would be over as soon as the Russians began their offensive. 

Then Truman received a full report on the successful testing of the atomic bomb:

Up until the time he received the full report on July 21 …, Truman and his advisors kept urging the USSR to enter the war as soon as possible. After that date, they kept trying to delay the Soviet entrance into the war. On July 26, the United States and United Kingdom issued the Potsdam Declaration, an ultimatum that demanded Japan’s “unconditional surrender” or face “prompt and utter destruction.” … As Ham and many others have argued, the demand for “unconditional surrender” effectively rebuffed the numerous Japanese attempts to negotiate a surrender, which had been going on for months.

Ham argues that the decisive event in this rapid sequence was: 

the Soviet juggernaut that destroyed Japan’s last great land army and terrified that nation’s leaders… At midnight on August eighth, the Red Army launched the largest land engagement of the entire Pacific war. Within a few days, almost 600,000 Japanese soldiers and hundreds of Japanese generals had surrendered. Eighty thousand had been killed… [The Soviet  campaign] captured from the Japanese in a week of colossal combat an area almost the size of Europe.

Before reading this review, I’d never heard of this large-scale combat between the Russians and the Japanese. As Franklin says, the story we all heard was that the Soviet Union had declared war on Japan after the atom bombs went off in order to join in the victory. America had already finished the job. But according to Ham:

A greater threat than nuclear weapons — in Tokyo’s eyes — drove Japan finally to accept the surrender: the regime’s suffocating fear of Russia. The Soviet invasion of August 8 crushed the Kwantung Army’s frontline units within days, and sent a crippling loss of confidence across Tokyo. The Japanese warlords despaired. Their erstwhile “neutral” partner had turned into their worst nightmare. The invasion invoked the spectre of a communist Japan, no less.

According to Ham, the bombing of Hiroshima and Nagasaki didn’t make much of an impression on the Japanese leadership. The firebombing of other Japanese cities, especially Tokyo, had already demonstrated our ability to destroy cities and kill civilians. Some of the Japanese leadership had already been advocating for peace. Franklin and Ham describe what happened next: 

An hour before the atomic bomb fell on Nagasaki, the war and peace factions of cabinet met in a bomb shelter under the Imperial Palace and began a furious and endless debate about the terms of surrender they should offer because of the Soviet invasion of Manchuria… Ham describes how they greeted the news of Nagasaki:

“Nothing of great moment had occurred in Hiroshima to persuade them of the futility of further defiance; the militarists scorned the weapon as a cowardly attack on defenceless civilians. Toward the end of the interminable discussion — now into its third hour — a messenger arrived with the news of the destruction of Nagasaki — by another ‘special bomb’. The [Japanese leaders] paused, registered the news, and resumed their earlier conversation. The messenger, bowing apologetically, was sent on his way. ‘No record … treated the effect [of the Nagasaki bomb] seriously,” noted the official history of the Imperial General Headquarters’.

The doves in the Japanese leadership had been demanding that the Emperor remain in power after a Japanese surrender. That was the single condition they had insisted on. Now the hawks agreed. Japan would surrender so long as the Emperor’s position would be maintained. The U.S., which had previously insisted on unconditional surrender, finally conceded that the Emperor would remain in power. The war was over. 

Given this evidence, it’s clear that the Soviet Union played an important role in ending the War in the Pacific. The stories about Soviet opportunism are clearly false (they had, after all, been carrying the brunt of the war again Germany earlier in 1945). Whether Truman should have dropped the bomb is another question. The most charitable interpretation is that he truly believed using the bomb would significantly shorten the war and save lives (not just American lives but Japanese and Russian lives?). A less charitable interpretation is that his real target was the Soviet Union. Using the bomb against Japan showed the Russians that America had the most powerful weapon in the world and was willing to use it. It also resulted in the Soviet Union controlling less of East Asia when the war ended and America controlling more. He probably had all these considerations in mind before he ordered the incineration of Hiroshima and Nagasaki.