August 6 is the anniversary of the atomic bombing of Hiroshima in 1945. It and the subsequent atom bombing of Nagasaki led quickly to the capitulation of the Empire of Japan, ending World War II. The history leading up to the bombings is compelling and has been the subject of intense debate here in the United States as well as the occasion for condemnation of America after the war by various factions both domestically and abroad.
My purpose here is not to assess those debates or accusations, but simply to relate the history and its context of the American decision to drop the two atom bombs and of Japan's decision to surrender afterward. How connected, exactly, was Japan's surrender to the bombings? The answer is surprising. The atom bombings, it turns out, did not cause Japan to surrender so much as it gave them the chance to do so honorably (honorably in their minds, that is).
(It must be considered, though, that throughout most of 1945, a half-million civilians were dying monthly at the hands of the Japanese in the Asian and Pacific lands Japan still occupied. Any criticism of the decision to drop the atom bombs must take this genocidal monthly death toll into account.)
Syndicated columnist Austin Bay posted the text of a letter written by James A. Michener to a friend in October, 1995. Michener was serving in the US Army Air Corps in the Pacific when the bombs were dropped. He wrote ,
Never once in those first days nor in the long reconsiderations later could I possibly have criticized Truman for having dropped that first bomb. True, I see now that the second bomb on Nagasaki might have been redundant and I would have been just as happy if it had not been dropped. And I can understand how some historians can argue that Japan might have surrendered without the Hiroshima bomb, but the evidence from many nations involved at that moment testify to the contrary. From my experience on Saipan and Okinawa, when I saw how violently the Japanese soldiers defended their caves to the death I am satisfied that they would have done the same on Kyushu. ...
[I]f you are unlucky enough to become engaged in [war] you better not lose it. The doctrine, cruel and thoughtless as it may sound, governs my thought, my evaluations and my behavior. I could never publicly turn my back on that belief, so I have refused opportunities to testify against the United States in the Hiroshima matter. . . . I know that I was terrified at what might happen and d----d relieved when the invasion became unnecessary. I accept the military estimates that at least one million lives were saved and mine could have been one of them.
I have known a few men who served in the armed forces in the Pacific who completely agree. My father-in-law, an Army officer in 1945, veteran of eight combat amphibious assaults in the Pacific, is convinced that he is alive because the atom bomb canceled the invasion of Japan. My father was assigned to the Pacific Fleet in 1945 and wound up on an aircraft carrier, serving a battle station as a 40-mm antiaircraft gunner. Carriers were primary kamikaze targets.
There are two essential books to understand what happened and why. One is a little-known work of Japanese historians, written eight years after the bombing, Japan's Longest Day . Their focus is on the period between the Nagasaki bombing and the radio address of Emperor Hirohito in which he announced that the war had not turned in Japan's favor. The authors painstakingly document the fact that even the atomic bombings did not persuade all the Japanese high command to surrender. A coup was actually attempted by an army general, who sent troops to occupy the emperor's palace grounds, take the emperor into protective custody and seize the recordings of his statement to be broadcast. The coup failed, of course, but as Wellington had said about Waterloo, it was a close-run thing.
The second book is an award-winning book, Downfall: The End of the Imperial Japanese Empire, by Richard B. Frank. A very comprehensive history, Frank documents the Japanese plan for defending against American invasion of the home islands, using Japanese documents and records. But his best contribution is the way he shows the context in which the Japanese bombings occurred.
Frank shows that the most destructive weapon used against Japan in 1945 was blockade, which robbed Japan of raw materials, petroleum and most vitally, food from the Asian mainland. The blockade was enforced by submarines and B-29 bombers, which laid mines throughout the Sea of Japan, concentrating on the approaches to Japan's harbors. Japan's industries were surprisingly resilient to aerial bombing but could not function when their raw materials were so successfully interdicted.
The remains of Nagasaki, destroyed by an atom bomb on August 9, 1945
Frank shows that within a day of the first bombing, Japanese scientists had correctly identified the weapon's type. Even so, no one's first thought was of surrender. The death tolls of the bombings and the extent of their physical destruction were neither remarkable nor unusual by that stage of the war. As far back as March, B-29s had killed far more people in one night of bombing Tokyo than died in either Hiroshima or Nagasaki. While the Japanese high council did understand that the atom bomb was an unstoppable weapon, well, so were the vast fleets of American bombers already pulverizing Japan's cities. (The high council, eight men who advised the emperor, ruled Japan without challenge. The Diet was toothless by 1945.)
The emperor and his government were united in a collective, non-negotiable condition for capitulation - that the emperor and his office must remain intact, along with the ancient symbols of his divine authority – something akin to the British crown jewels and scepter; the closest American equivalents are the original copies of the Declaration of Independence and the Constitution. The emperor's line had continued unbroken for 2,600 years and his imperial regalia had been passed down from time immemorial. Together they defined the national polity. Japan Zone explains ,
According to the historical chronicles of ancient Japan, the Kojiki (Record of Ancient Matters, AD712) and the Nihon Shoki (Chronicle of Japan, AD720), the sun goddess Amaterasu Omikami presented the sanshu no jingi or Imperial Regalia to her grandson, Ninigi no Mikoto. He in turn passed them on to his descendants, the emperors, the first of whom was Emperor Jimmu. The regalia, a mirror, a sword and a curved jewel are symbols of the legitimacy and authority of the emperor. These creation myths also form the foundations of the indigenous Shinto faith.
At the insistence of General Douglas MacArthur, who knew Japan, its history and culture intimately, America covertly promised to leave intact the emperor's throne and regalia long before the atom bombings. The Allies issued Japan the Potsdam Declaration on July 26, 1945, directing Japan to surrender or "face prompt and utter destruction." Only two days later Japan's government rejected the ultimatum out of hand. On July 31, Emperor Hirohito told the Lord Keeper of the Privy Seal, Koichi Kido (a member of the high council) that the imperial regalia would have to be protected at all costs.
Despite the secret guarantees, none of the high council agreed to surrender before the atom bombings occurred. Japan's prosecution of the war never let up. The Truman administration and military commanders began to wonder whether, short of actual invasion, Japan could be brought to surrender. (Several of the high council never agreed to surrender even after the atom bombings.)
Until 1995, very large amounts of American records from the months before the bombings remained classified. These records included minutes of meetings of very high-level American civilian officials and military officers. The more conspiracy-minded of historians claimed that the decades-long classification of these records were meant to conceal the enormous rifts within the government over using the atom bomb, and that the hawks of the government and armed forces had succeeded in quashing objections.
However, when the records were released in the '90s, no such rift was evident. While it is true that a number of officials and generals expressed dismay or reservations later (often years later), they never uttered objections before the bombings.
So why were the files classified so long? The answer is mundane: they showed that not only were US intelligence services intercepting and decoding Japanese communications, they were doing the same with the communications of almost 30 other countries, many allied with the United States, including our closest ally, Britain,
These interceptions included those of non-belligerent nations that still maintained embassies in Tokyo. Their communications to their home governments in 1945 were nearly unanimous that Japan would not capitulate. It would fight to the bitter end.
Another thing that the files revealed was that a serious rift over US policy and plans against Japan was developing before the atom bombings, but not over the atom bomb or its use. The rift was over the prospect on invading Japan. And the neutral nation's diplomatic messages were part of the reason.
American planners' estimates of casualties on both sides following an invasion were shockingly high. The recent bloodbath of the battle for Okinawa evoked a split among the American joint chiefs of staff over the prospect of invasion. Half the service chiefs became opposed to invasion because the human toll was unacceptable. Richard Frank concludes in an online essay that this rift was not quite fully set by the end of July but that, absent Japan's captitulation in August, the president would have decided not to invade the Japanese home islands and would have ordered other means to force surrender.
What could those other ways have included? Even if Hiroshima and Nagasaki had not been destroyed by atom bombings, they would not have been spared destruction by massive, conventional bombing. The air campaigns against Japanese cities and lines of communication - rail lines, roads, bridges and the like - would have continued, even though by mid-1945 they were mostly destroyed. Japan's cargo fleet was mostly sunk. Japan had no navy left to speak of. What it did have was thousands of airplanes, millions of soldiers and militia and near-limitless stocks of ammunition, held in reserve to oppose invasion.
Hence, American strategy, absent invasion, could only have consisted of two things:
1. More atom bombings. The atom bombings of Japanese cities would not have stopped with Hiroshima and Nagasaki. Manufacture of atom bombs was scheduled to ramp up to at least two per month before autumn and other target cities had already been identified.
2. Tightening the already-choking blockade. It's worth remembering that as late as World War One, blockade as a war measure was condemned as inhumane and even criminal because its effects spread across all the people of the blockaded country, without regard to age, sex, or status as soldier or civilian. Cut off from Asian mainland food stocks, the Japanese were coming dangerously close to actual starvation by late spring 1945. The per capita, daily calorie intake had fallen to significantly less than the minimum required and was declining steadily. Even after the war, typhoons so damaged Japan's rice fields in October 1945 that massive US food aid was required to prevent mass starvation. Had the war still been going on then, as it would have without the atom bombings, the Japanese death toll would have been very high.
As you can see, though, such a "strategy" is no strategy at all. It is a spasm. Had President Truman not ordered the atom bombings, the US military could have done nothing but intensify conventional bombing and blockading. Hence, Japan could not possibly have been brought to a gentler end of the war than the ending that occurred. Had fighting continued after early August 1945, additional civilian deaths would certainly have numbered in the many hundreds of thousands and probably in the millions by the end of the year.
More likely, though, is that without the atom bombings, Japan would have become embroiled in civil war, which also would have been lethal beyond estimate. Japanese records show that the overriding fear of Japan's high council was the destruction of the emperor's office and line, and the most serious threat thereto was revolution by the Japanese people themselves. The American blockade was so punishing the people that Japan's internal security service, the Kempei Tai, had soberly concluded that revolution was becoming ever-more possible. Even the most hawkish of the council were petrified by this prospect, realizing that people who were literally starving could never be reasoned with to endure obediently to their deaths, especially as they watched their children suffer. The council also had no way to ensure that army units would remain loyal to the emperor once the people took to the streets - the soldiers were hungry, too.
Hence, the atom bombings provided an opening for a face-saving way to end the war. Petrified by the prospect of civil revolution, the high council could preserve its honor (as it understood it) by claiming that the atom bomb was a new weapon of such power that resistance was no longer preferable or possible. This was indeed the tack they took. Not every member of the high council agreed even so; some were willing to risk that the American invasion would come before a domestic revolution broke out and that once US troops were ashore, the people would unite to fight the enemy.
Finally, Emperor Hirohito himself broke the impasse, speaking directly to the high council, which had never been done before. He declared that "the time has come when we must bear the unbearable....[so I] give my sanction to the proposal to accept the Allied [Potsdam] Proclamation," that had directed Japan to surrender or face utter destruction.
The atom bombings, then, provided the opening rather than a fundamental reason to accept the Allies' terms. With the assurance that the Americans would neither abolish the emperor's office nor claim the imperial symbols as war prizes, surrender became the only guarantee that the national polity could continue. Hence it was less undesirable than continuing the war, which would have only invited more destruction and then revolution.
Update, 8/19/2023: This video on YouTube came out just four days ago.