Sunday, August 15, 2010

Dyson, the bomb, and the Japanese surrender

This interview with Freeman Dyson pointed me to the recent reanalysis by historian Tsuyoshi Hasegawa of the Japanese surrender at the end of WWII. There is an old controversy over whether the atomic bombs or the entry of the USSR played the decisive role. Were the bombs necessary at all? Dyson mentions (about 30 minutes into the interview) that, due to Hasegawa, he is now 90 percent confident that they were not. This despite his close association with many of the Manhattan Project figures (Oppenheimer, Bethe, Teller, Feynman and others), and his acceptance for sixty years that atomic weapons played the key role. Dyson's recapitulation in the interview is quite good (it starts at about 20 minutes); see also here.

I recently learned from Donald Keene's diary translations (see also here) that Japanese modernizers had been worried about the Russian threat since the Meiji era.

Dyson also has some interesting comments about space exploration and genomics immediately following the discussion about nuclear weapons. I almost skipped listening to this interview, having spent several hours with him relatively recently. But someone as knowledgeable and brilliant as Dyson will always generate surprising insights.

Hasegawa's book: Racing the Enemy: Stalin, Truman, and the Surrender of Japan

Summary: ... According to Hasegawa, Japanese leaders' diaries and testimonies suggest that the imminent Soviet invasion was more influential in compelling them to accept the Potsdam conditions. Although Emperor Hirohito's desire to end the war became more urgent after Hiroshima, only on August 9 after the Soviet declaration of war did he clearly say that "it is necessary to study and decide on the termination of the war" [26]. The other peace advocates in the Foreign Ministry on the same day began to urge acceptance of the Potsdam ultimatum [27]. The reactions of the more hawkish military officials seem to have been similar. Both Admiral Toyoda and Army Deputy Chief of Staff Kawabe were surprised at the news of Hiroshima but were not ready to temper their views on continuing the war [28]. Many military officials hoped to mount a final defense, but had counted on Soviet neutrality in order to do so [29]. The Soviet declaration of war destroyed those hopes, and severely weakened the war faction's leverage within the government.

The major strength of Hasegawa's work, and one reason for its new arguments, is its in-depth analysis of Japanese primary sources. Few previous historians in the US had consulted the personal writings of figures like Toyoda, Kawabe, and Tanemura. But Hasegawa also makes more extensive use of Allied primary sources, including the memoirs and diaries of Truman, Byrnes, Brown, and others, which play a key role in his argument about the intent of the Potsdam Proclamation. Hasegawa's careful scholarship has significantly enriched our understanding of the intentions behind the demand for "unconditional surrender," as well as the dynamics behind the Japanese decision to surrender.

I recently had a memorable conversation with a colleague (another former Junior Fellow) who is a professor in the history department. Despite early evidence of talent in mathematics, he decided to study history because he wanted a career in which his abilities would continue to grow and deepen well into maturity. He preferred to reach the peak of his powers late in life, rather than suffer the continuous decline so dreaded by precocious young geniuses in theoretical subjects. I begin to see his point.


ben g said...

What's Hasegawa's view on what the US knew about Japanese itnentions at the time? Was it reasonable from the perspective of the US that it would require nukes to end the war?

Jin Dih said...

"Were the bombs necessary at all?"

Why do people waste their time debating this? As if claiming "Had I been President ..." isn't ridiculous.

If it hadn't been Hiroshima and Nagasaki it would have been somewhere else, like Korea, or Vietnam.

Only after the effects of the bomb had been seen would the thought of using them become hateful to everyone.

Someguy said...


Why chance it? The point it to win the war (started by the Japs) and to lose as little life as possible. Drop 20 atom bombs if needed.

Surreptitious Evil said...

I think that this is the key question. Detailed release of historical documents allows us to analyse what could have been done with much more detailed access to information about the intention of others (accepting, of course, that not everything that was discussed or would have happened, especially the more embarrassing stuff, makes it in to the historical record.) Questions about the morality of action, and even sometimes the legality of action, need to consider the information available or readily available to the actors. US and Japanese losses in the island hopping campaigns had been severe. Civilian suicides in Okinawa, both voluntary rather than surrender and ordered / forced by the Japanese Army, had shocked commanders. As, I suspect, had the deterioration in morale amongst the US troops in the fighting, with nearly as many withdrawn from combat stress as were wounded or killed.

Yes, we didn't know much about the effects of fission weapons - or that the peculiarities of Japanese architecture would exacerbate the effects. But they did know it was going to kill a lot of people - although still less than the conventional (fire)-bombing of Dresden or Tokyo.

Russo-Japanese War (1904-05), anybody? I suspect that senior military figures had been junior officers when that was going on. Best known in the UK, of course, for the Russian Baltic Fleet, on passage, mistaking the Hull trawling fleet at the Dogger Bank grounds for Japanese torpedo boats.

Eric Foss said...

In thinking about this issue, it is important to consider: (1) whether or not the bombs ended the war; (2) whether or not the bombs were necessary to end the war; and (3) whether or not, if the bombs were NOT necessary to end the war, the Truman administration knew this before they dropped the bombs.

My view is this (and I can back it up with a lot of documentary evidence): The bomb was not used because people in the Truman administration thought that it was necessary in order to end the war. They knew that the war would end if the Russians declared war, and they knew that the Russians would declare war somewhere around August 8. They knew that the war would end if they assured the Japanese that they (the Japanese) could keep their emperor in an agreement essentially identical to the one that was acceptable by the U.S. after the bombs were dropped, but not before. The Truman administration knew that if they just waited, the war would end before they were even tactically capable of an invasion of Japan. The motivation for dropping the bombs had everything to do with our relationship with the Russians - we had to drop them to demonstrate our power to the Russians before the war inevitably ended. It was mass murder of civilians for geopolitical reasons vis a vis the Russians.

The chief historian of the U.S. nuclear regulatory agency writes this in 1990 in the the journal "Diplomatic History":

"Careful scholarly treatment of the records and manuscripts opened over the past few years has greatly enhanced our understanding of why the Truman administration used atomic weapons against Japan. Experts continue to disagree on some issues, but critical questions have been answered. The consensus among scholars is that the bomb was not needed to avoid an invasion of Japan and to end the war within a relatively short time. It is clear that alternatives to the bomb existed and that Truman and his advisers knew it."

Yourlyingeyes said...

I'm sure Russia's entry into the war was not a welcome development for the Japanese, but did Russia realistically have any kind of amphibious assault capabilities to seriously threaten the Japanese homeland, or the airborne capability to do much more damage than the Americans were doing?

Pincher Martin said...

" They knew that the war would end if the Russians declared war, and they knew that the Russians would declare war somewhere around August 8."

You speak very authoritatively. Document how the Truman administration knew that the Japanese would surrender if the Russians entered the war in early August.

You are basically arguing that the Truman administration was highly confident in its knowledge of the planned actions of two other state actors (the Russians and the Japanese) and hurried to test a weapon on civilians for no other purpose than to thwart those plans for unspecified geopolitical reasons.

Eric Foss said...

"You are basically arguing that the Truman administration was highly confident in its knowledge of the planned actions of two other state actors (the Russians and the Japanese)..."

Yes. Remember, we had broken the Japanese codes and knew exactly what they were saying internally and also externally, e.g. to the Russians. And we had expected the Russians to enter the war 3 months after the German defeat (May 8), since that's how long it would take them to get their army from the western front over across Siberia.

"... and hurried to test a weapon on civilians for no other purpose than to thwart those plans for unspecified geopolitical reasons."

No - not to thwart those plans. I'm arguing that they hurried to demonstrate to the Russians that they had this power before they would no longer have an excuse to do something this horrific (i.e. before the Japanese surrendered). The big conflict looming was not with the Japanese - they were finished - it was with the Russians.

Here's some documentation:

U.S. Strategic Bombing Survey (1946): "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 invasion had been planned or contemplated."

April 1946 War Department study, Use of Atomic Bomb on Japan:

"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." .... [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."

"the dropping of the bomb was the pretext seized upon by all leaders as the reason for ending the war, but ... [even if the bomb had not been used] the Japanese would have capitulated upon the entry of Russia into the war."

April 29, 1945, the Joint Intelligence Committee (JIC), Unconditional Surrender of Japan: "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 entry of the USSR into the war would, together with the foregoing factors, convince most Japanese at once of the inevitability of complete defeat."

June 1945, General Marshall to Truman: "the impact of Russian entry [into the war] on the already hopeless Japanese may well be the decisive action levering them into capitulation at the time or shortly thereafter if we land in Japan."

July 1945 British general Sir Hastings Ismay to Churchill: "When Russia came into the war against Japan, the Japanese would probably wish to get out on almost any terms short of the dethronement of the Emperor."


Truman's characterization of a telegram intercepted on July 12, 1945: "telegram from Jap Emperor asking for peace."

Pincher Martin said...

"Yes. Remember, we had broken the Japanese codes and knew exactly what they were saying internally and also externally, e.g. to the Russians."

Did the Japanese tell the Russians in mid-1945 that they were prepared to surrender if Stalin declared war against Japan? Your sources do not provide any evidence to support this view. Instead, you rely on Western sources, like Marshall and Ismay, which was qualified and less than convincing of any Western certainty in Japanese motives before the bomb was dropped.

Steve Sailer said...

An easy fallacy is to assume that there was a unitary Japanese decision-making entity that reacted to events based on cost-benefit analysis. So, you can pick any particular Japanese high official to make the point you want to make.

In reality, Japanese politics has been driven by assassinations of moderates for much of the previous two decades, which set in motion a Crazier than Thou dynamic that led to Japan being bombed flat (atomic and conventional). For example, Admiral Yamamoto spent the year he devoted to planning Pearl Harbor at sea for fear that he would be murdered by Army crazies for insufficient craziness if ever set foot on land.

The Japanese government in August 1945 had a Really Bad Week: Hiroshima on August 6, the Soviet attack on August 8, Nagasaki on August 9. Early on the morning of August 10, the Emperor finally spoke up in cabinet and called for surrender. But even after he recorded a surrender speech on a record to be broadcast August 15, there was still a military coup attempt that held him prisoner over night and a running gun battle as Army crazies tried to seize the record and smash it before it was broadcast.

Eric Foss said...

I've documented that the US knew that the entrance of the Russians would lead the Japanese to surrender. (The US also knew that simply telling the Japanese that they could keep their emperor, albeit in a powerless position like the Queen of England, would end the war. For some reason, that ended up being fine with the US after the bombs were dropped but was unacceptable beforehand.) In response to your question: I would be extremely surprised if the Japanese told the Russians in mid-1945 that they would surrender if Stalin declared war on them. Why would they? That's not how diplomacy works. They were, however, desperately seeking peace through all sorts of channels and they were bending over backwards to please the Russians on issues like Manchuria. We knew that at the time because we we had broken their diplomatic codes and were intercepting their messages. And these efforts included a highly unusual intervention by the emperor himself, sending his own personal envoy, Prince Konoe, to plead for peace with the Russians. Rather than spending my time digging up further documentary evidence, I'll point you in this direction:

I think that it is incontrovertible that dropping the bomb was unnecessary to end the war and that Truman et al. knew it. And I have a hunch that the chances of you ever believing that are slim to none.

Yan Shen said...

So Steve, are you going to bother explaining why you let comments containing explicit racial slurs to slip through your moderation? As a self avowed endorser of citizenism, you seem to be surprisingly unconcerned about the well being of some of your fellow American citizens.

steve hsu said...

Eric, thanks for your informative comments. I guess maybe you could have convinced Dyson long before Hasegawa did!

Yan Shen: what slurs are you referring to? I'm fairly busy and I assume everyone is a grownup around here, so I try to keep a light hand when it comes to censoring comments. The only time I've had to do it was with a commenter called anon. He's back (under new pseudonyms) but so far has been on good behavior.

Yan Shen said...

I was referring to Steve Sailer, not you Steve Hsu. :) I've noticed that Steve Sailer has a penchant for tolerating racial slurs on his blog.

Pincher Martin said...

"I've documented that the US knew that the entrance of the Russians would lead the Japanese to surrender."

No, you have not. You have documented that some in the U.S. and British commands considered it a possibility, even a likelihood. You have also documented that some U.S. reports, written after the war was over, took the position that a Japanese surrender was likely even without dropping an atomic bomb.

"In response to your question: I would be extremely surprised if the Japanese told the Russians in mid-1945 that they would surrender if Stalin declared war on them. Why would they? That's not how diplomacy works."

Well, then what's the point of alluding to the U.S. having broken the Japanese code?

For the U.S. to have a high degree of confidence that the Japanese would soon surrender, they would need detailed and direct knowledge to that effect from the most powerful decision-makers in Japan at the time. And they would need to know it before the bomb was dropped.

So unless you can point to key Japanese intelligence that you know the U.S. command possessed and discussed before August 1945, you have no case. Referring vaguely to "how diplomacy works" is not a case. Referring to General Marshall's comment that the Russian entry into the Pacific theater "may well be the decisive" action which leads to Japan's capitulation does not support your case. Referring to after-action reports that claim the Russian entry "would almost certainly" lead to Japan's surrender does not support your case.

"Rather than spending my time digging up further documentary evidence, I'll point you in this direction:"

As I suspected, you are relying on the leftist revisionist historian Gar Alperovitz, a historian who knows no Japanese and who has been criticized for his artful editing of U.S. sources.

Jill said...

During WWII I was just a kid growing up in a tenement in the Bronx. My Mom's sister lived a few floors above us. In the Spring of 1945 my mom's sister received notice of her Marine husbands death on Okinawa. As I slept that night I could hear my Aunt's wailing and screams that lasted all night and all through the next morning. I will never forget her suffering and despair. I doubt if Dyson has ever felt that kind of pain. Dyson does not speak for my family nor does he speak for the millions of surviving family members in the United States and Asia who suffered from the Japanese onslaught.

I will leave you with the words of President Truman in August, 1945:

"Having found the bomb we have used it. We have used it against those who attacked us without warning at Pearl Harbor, against those who have starved and beaten and executed American prisoners of war, against those who have abandoned all pretense of obeying international laws of warfare. We have used it in order to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans.

"We shall continue to use it until we completely destroy Japan's power to make war. Only a Japanese surrender will stop us."

DK said...

Nukes had very little to do with winning the war with Japan. Nukes were a very graphic message to the uncle Joe over at Kremlin. Nothing else. Russians were rounding Japanese by a million a day in China and no matter how deluded some Japanese at this point were, they wouldn't be able to put up much resistance against overwhelming American power in the Pacific. So here you go: 100,000 civillians killed to start a Cold War.

Carl said...

Your comment does not relate to the point in question here. We all agree that Japan had to be stopped. We all agree that an invasion of the core islands of Japan would have been horrific. The question is whether the Soviet entrance into the war would have been sufficient to stop Japan by itself. If this is true, then the war would have ended on the exact same day, even if Hiroshima and Nagasaki had never been bombed. That's the question under discussion.

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