Did Truman know Hiroshima was a city?

[Admiral Yi]

There's some evidence to suggest not only did they know there were a lot of civilians there but that this was entirely part of what they were aiming for.
They WANTED a live test of the bomb on a civilian population. The war was going to be over soon and they wouldn't get a better chance at testing the bomb than against the thoroughly hated and dehumanised Japanese, bonus points for being able to spin the bomb as a miracle war winning wonder weapon.

As for avoiding bombing the capital and Hiroshima being purely military- thats just reference to the cultural value of the cities. Hiroshima did have a major military base but not much in the way of special cultural value. Unlike Tokyo and especially Kyoto.
On that same note its such a shame Kokura had fog. Its so much more of a concrete nothing than Nagasaki.

Even if you don't like the human experimentation angle on the bomb its certain that at the time there was a huge amount of acceptance of collateral damage and levelling half a city just so long as you were knocking out a military target with it.
Terror bombing a purely civilian target on the other hand was quite different.

The war would over soon in large part, if not entirely, because of the atomic bombs.  Without them the military was forecasting (IIRC) horrendous US casualties from the invasion of the Japanese islands.

Other people have mentioned it, but you're talking as if bombing civilians and destroying their homes was some sort of taboo.  Bomber Command had been gutting German cities for years.  The US had been doing the same to Japanese cities.

I've read that the US considered the possibility of detonating the first bomb in an unpopulated area as a warning, but decided against it because of the possibility the Japanese would consider it a bluff, and because the US had so few operational A bombs.

[Admiral Yi]

There's some evidence to suggest not only did they know there were a lot of civilians there but that this was entirely part of what they were aiming for.
They WANTED a live test of the bomb on a civilian population. The war was going to be over soon and they wouldn't get a better chance at testing the bomb than against the thoroughly hated and dehumanised Japanese, bonus points for being able to spin the bomb as a miracle war winning wonder weapon.

As for avoiding bombing the capital and Hiroshima being purely military- thats just reference to the cultural value of the cities. Hiroshima did have a major military base but not much in the way of special cultural value. Unlike Tokyo and especially Kyoto.
On that same note its such a shame Kokura had fog. Its so much more of a concrete nothing than Nagasaki.

Even if you don't like the human experimentation angle on the bomb its certain that at the time there was a huge amount of acceptance of collateral damage and levelling half a city just so long as you were knocking out a military target with it.
Terror bombing a purely civilian target on the other hand was quite different.

The war would over soon in large part, if not entirely, because of the atomic bombs.  Without them the military was forecasting (IIRC) horrendous US casualties from the invasion of the Japanese islands.

Other people have mentioned it, but you're talking as if bombing civilians and destroying their homes was some sort of taboo.  Bomber Command had been gutting German cities for years.  The US had been doing the same to Japanese cities.

I've read that the US considered the possibility of detonating the first bomb in an unpopulated area as a warning, but decided against it because of the possibility the Japanese would consider it a bluff, and because the US had so few operational A bombs.

[PDH]

You can say that again.

[Sheilbh]

Actually, Racing the Enemy is well-reviewed in the sense that it has some valuable primary source access, but not so well-reviewed when it comes to the conclusions about why Japan surrendered when it did.  Hasegawa's claim that the Soviet entry into the war was decisive is based solely on the statement to that effect by the Japanese Ambassador to the Soviet Union (se, for instance, https://middlegroundjournal.com/2013/10/28/review-of-racing-the-enemy-stalin-truman-and-the-surrender-of-japan-by-tsuyoshi-hasegawa-harvard-university-press/)

Hasagawa's claim also faces the challenge of explaining why the Big Six had their turn-around on the day after Nagasaki was bombed, rather than the day after the USSR declared war.  He says that this was because the Japanese were too shocked on the 9th, but that doesn't seem to be ore than rationalization.

Although weren't they effectively on the same day, because the Soviet entry into the war was probably a surprise as it's likely that Sato couldn't communicate with Japan? Sato was informed on 8 August that the USSR would enter the war "tomorrow" on 9 August. The meeting with Molotov was at about 5pm Moscow time and continued for a bit. Sato asked for permission to inform Tokyo before midnight, which Molotov agreed. But Sato didn't clarify which timezone the state of war would start in - the USSR invaded at midnight Transbaikal time (six hours ahead of Moscow). So Sato only had less than an hour from his meeting to wire Tokyo, if the Soviets would let it out in any event. Given that Molotov's declaration said that the Soviet Ambassador in Tokyo would be simultaneously informing the Japanese government - which didn't happen it feels likely. The Japanese only became aware of the war through the invasion along the entire Soviet front at 4 am - and just a few hours before Nagasaki. Not allowing Sato to communicate/using timezones like that does also accord with other behaviour by Stalin and Molotov.

Hasagawa also apparently admits that the Emperor mention the a-bomb in his decision to surrender but not the USSR, but apparently makes no attempt to reconcile this evidence with his Hasagawa's own assertions.

Doesn't that depend on which communication from the Emperor you look at - the communication to the soldiers and sailors which does the opposite. It mentions the USSR but not the A-bomb. I believe Hasegawa's thesis on the Emperor is that the entry into the war of the USSR presents a far greater threat to the imperial throne and household (and raises the risk of Communist revolution as well as territorial losses) and tilts the balance for him towards surrendering to the US. The cabinet secretary's documents also refer to both.

And I think he also quote Kawabe from the command which does give a sense of the double shock effect on Japan:

When the atomic bomb was dropped, I felt: "This is terrible." Immediately thereafter, it was reported Soviet Russia entered the war. This made me feel: "This has really become a very difficult situation."

Russia's participation in the war had long since been expected, but this does not mean that we had been well prepared for it. It was with a nervous heart filled with fear that we expected Russia to enter the war. Although it was a reaction of a man who was faced with the actual occurrence of the inevitable, mine was, to speak more exact, a feeling that "what has been most [feared] has finally come into reality." I felt as though I had been given a thorough beating in rapid succession, and my thoughts were, "So not only has there been an atomic bombing, but this has come, too."

I believe that I was more strongly impressed with the atomic bomb than other people. However, even then, ... because I had a considerable amount of knowledge on the subject of atomic bombs, I had an idea that even the Americans could not produce so many of them. Moreover, since Tokyo was not directly affected by the bombing, the full force of the shock was not felt. On top of it, we had become accustomed to bombings due to frequent raids by B-29s.

Actually, [the] majority in the army did not realize at first that what had been dropped was an atomic bomb, and they were not generally familiar with the terrible nature of the atomic bomb. It was only in a gradual manner that the horrible wreckage which had been made of Hiroshima became known, instead of in a manner of a shocking effect.

In comparison, the Soviet entry into the war was a great shock when it actually came. Reports reaching Tokyo described Russian forces as "invading in swarms." It gave us all the more severe shock and alarm because we had been in constant fear of it with a vivid imagination that "the vast Red Army forces in Europe were now being turned against us." In other words, since the atomic bomb and the Russian declaration of war were shocks in a quick succession, I cannot give a definite answer as to which of the two factors was more decisive in ending hostilities.

And Toyoda recorded that while he felt the A bomb was a cause and it wasn't the only cause. The military felt the bomb wouldn't be regularly used (I think correctly, if the war had gone on). He noted that the Soviet invasion was a bigger shock because the military that would happen in autumn and it "became impossible for us to map any reasonable operation plan. Moreover, the peace program which we had so far relied on came to naught [...] I believe the Russian participation in the war against Japan rather than the atomic bombs did more to hasten the surrender." Obviously all of those are memories after the event - and it must have been an incredibly chaotic time just three days and Japan was facing two atomic bombs and massive invasion.

[Berkut]

I guess I am an asshole, but this is so tiring.

I have zero confidence that the entire "It was the Soviets!" myth has any basis at all in any honest curiosity about what motivated the Japanese surrender, and is instead absolutely and completely 100% motivated by the desire to make sure the the use of a nuclear weapon be seen as being unambiguously evil, because it didn't actually even do what it was supposed to do anyway.

There is nothing more to this argument then that.

The historical record is pretty simple, and completely obvious. You can read the damn notes about the decision making process of the people who are actually making the decision. This isn't complicated.

[The Minsky Moment]

I won't even go into Hasagawa's unsupported* assertion that Truman placed the unconditional surrender demand in the Potsdam Declaration because he didn't want Japan to surrender until the a-bomb was used.  That's just too far out there, and ignores the fact that unconditional surrender had been demanded of all the Axis powers in WW2.

In an attempt to ward off the inevitable disaster, the Axis propagandist are trying all of their old tricks in order to divide the United Nations. They seek to create the idea that if we win this war, Russia, England, China, and the United States are going to get into a cat-and-dog fight.

This is their final effort to turn one nation against another, in the vain hope that they may settle with one or two at a time-that any of us may be so gullible and so forgetful as to be duped into making "deals" at the expense of our Allies.

To these panicky attempts to escape the consequences of their crimes we say-all the United Nations say-that the only terms on which we shall deal with an Axis government or any Axis factions are the terms proclaimed at Casablanca: "Unconditional Surrender."

FDR, Feb. 1943

It is inconceivable that any intelligent statesman in Japan could have any illusion about the possibility of a negotiated peace with conditions in the US in 1945.

And it is completely insane to think that Truman would conceive of such of thing, much less act upon it.

[Sheilbh]

It is inconceivable that any intelligent statesman in Japan could have any illusion about the possibility of a negotiated peace with conditions in the US in 1945.

I don't think that there is any significant dispute amongst serious historians that the Japanese were going to stake everything on a battle to repulse an invasion.  There is a popular misconception that the Soviet DOW shocked the Japanese, but that's false.  The USSR had denounced the non-aggression treaty the previous April and the question was only when they would attack Japan, not whether they would.  And it is also untrue that the Japanese government thought or even wanted the USSR to mediate a peace; that effort was entirely the individual efforts of specific Japanese diplomats in the USSR and quickly was denounced by both the Soviets and their own Foreign Ministry superiors.

Although I feel this is wrong on the peace negotiation:
https://www.nationalww2museum.org/war/articles/japanese-diplomacy-1945

It was run through Sato in Moscow but on instructions from Tokyo - and Sato was disabusing his superiors of the idea that it would work if all they were saying were "pretty little phrases devoid of all connection with reality". Sato was apparently pretty clear that the only real option was unconditional surrender. But I don't think it can be called an individual effort.

There were intelligent statesmen working for Japan (though from a safe-ish location overseas), but I think it seems that the rest of the statesmen were wrongly thinking there could be some form of negotiated peace. But they weren't from what I can see really setting out what their idea of peace would look like, possibly because they knew surrender was inevitably the only option, so to think seriously of peace would require confronting that and instructions to get the Soviets to mediate were maybe a sort of displacement activity.

[The Minsky Moment]

Sometimes discussions of these issues seem to miss some basic political facts.

For example, the United States was an electoral democracy.  Its current President - Truman - was perceived as a lightweight and political hack suddenly thrust into a great position of responsibility following the death of the most popular President in American history.  These facts were all known and yet somehow obvious conclusions that follow are missed.

FDR had publicly announced the unconditional surrender policy and repeated the formula for years.  The idea that Harry Truman, after less than 4 months in office, would consider breaking with that policy and offer terms to Japan is bonkers. It would be more rational for a Japanese statesman to bank on an alien invasion taking out the USA than to place their hopes on a change in that policy.  To the extent there were Japanese statesman acting or talking as though such a thing was a viable option, that says more about the dysfunction of Japan's political regime at the moment in time.

As for the A-Bomb, the American public was going to learn about it sometime before Congressional elections in Nov 46 and the next Presidential elections in Nov 48.  If the bomb had not been used in August 45 and the war had continued for months after that, what would the reaction of the US people be when they learned that this powerful weapon was left unused?  What would the families and friends of the soldiers who died in the interim say and think and do?   It is inconceivable that the weapon would not have been used. 

[Berkut]

I think a lot of the angst on this comes from what we understand about nuclear weapons NOW.

At the time, the atomic bomb was not that different then what was already available. We killed more people, and did more damage, fire bombing Tokyo a couple months earlier in one night then what happened at Hiroshima. The difference was not in outcome, but rather in effort required. It took hundreds of bombers carefully coordinated with cooperative weather to butcher 100,000 civilians in about the worst way possible with firebombing. It took a couple bombers and one bomb that could be repeated over and over and over again to destroy Hiroshima.

So the idea that there was some kind of difficult moral decision to be made by the men involved is simply not the case. The moral decision had *already* been made that killing massive number of civilians was to be desired. This just did so in a different manner.

We all know that this was the start to something that WAS different in actual kind. We all know that from Hiroshima we would enter a world of MIRVed ICBMS lurking beneath the ocean ready to literally wipe out humanity, and some grotesque concept perfectly and aptly named MAD was the only thing stopping the end of humanity.

Truman might have imagined that, but almost certainly not in any way that matter in mid 1945. I don't even think it was presented to him (IIRC) as  "Hey, we have this really big bomb, should we use it?" Rather it was "Hey, just thought you should know, we have this really big bomb which we will be using...". And why wouldn't he use it? It was going to killa bunch of people really fast and easy instead of with a lot of work, and hopefully that would convince those damn Japanese to finally end this idiotic war.

There wasn't any great moral wailing and gnashing about whether or not to use it. That means that either

a) Doing so was, in the context of the time and the men making the decision, not morally very questionable, or
b) Truman and everyone involved were absolute monsters who just loved to kill as many people as possible and were probably happy there was a global war so they could indulge their mass psycopathy.

[The Brain]

Haberdashers gonna haberdash.

[Josquius]

There's some evidence to suggest not only did they know there were a lot of civilians there but that this was entirely part of what they were aiming for.
They WANTED a live test of the bomb on a civilian population. The war was going to be over soon and they wouldn't get a better chance at testing the bomb than against the thoroughly hated and dehumanised Japanese, bonus points for being able to spin the bomb as a miracle war winning wonder weapon.

As for avoiding bombing the capital and Hiroshima being purely military- thats just reference to the cultural value of the cities. Hiroshima did have a major military base but not much in the way of special cultural value. Unlike Tokyo and especially Kyoto.
On that same note its such a shame Kokura had fog. Its so much more of a concrete nothing than Nagasaki.

Even if you don't like the human experimentation angle on the bomb its certain that at the time there was a huge amount of acceptance of collateral damage and levelling half a city just so long as you were knocking out a military target with it.
Terror bombing a purely civilian target on the other hand was quite different.

The war would over soon in large part, if not entirely, because of the atomic bombs.  Without them the military was forecasting (IIRC) horrendous US casualties from the invasion of the Japanese islands.

Other people have mentioned it, but you're talking as if bombing civilians and destroying their homes was some sort of taboo.  Bomber Command had been gutting German cities for years.  The US had been doing the same to Japanese cities.

I've read that the US considered the possibility of detonating the first bomb in an unpopulated area as a warning, but decided against it because of the possibility the Japanese would consider it a bluff, and because the US had so few operational A bombs.

I never said anything about the morality of the atomic bombs. In fact I said that bombing cities was seen as acceptable at the time with precision bombing being a far future dream.

I've read that using the bomb on an unpopulated area was considered too but this doesn't really make sense. They'd already done that in the US and if they drop it on an unpopulated island then who is going to be around to see it? It would serve no purpose. It would also mean missing out on the valuable opportunity to use the bomb against an actual city and be able to properly analyse its damage.
I could be wrong but I don't recall any sources from the time actually proposing an unpopulated target, a quick google and I just find modern people saying it was an option.

The bomb in no way saved vast numbers of American lives. Thats a nonsense. An American invasion of Japan just wasn't going to happen. The timelines just didn't line up for it. At the very least long before America got around to this the Soviets would have landed on Hokkaido and the need to surrender vastly stepped up.
The commonly repeated saving over a million American lives in an invasion thing incidentally is part of the post war propaganda effort to justify the decision to drop the bomb and claim its role as war winning wonder weapon. Its not based on contemporary estimates.

Even sans the bombs Japanese surrender wasn't far off. They were already putting out big peace feelers, the only sticking point was that they wanted to talk (as was the norm) whilst the allies insisted on an unconditional surrender... And it was basically just fear of something happening to the emperor which was Japan's main sticking point there.
Also its notable that when the decision to drop the bombs was made Japan hadn't yet gotten the memo from the Potsdam declaration that unconditional surrender was the only way to end the war. Again this points towards the Americans being really keen to use the bomb rather than it being a weapon of last resort.

[Admiral Yi]

If you're going to make the bold claim that the US invasion of Japan was not going to happen, if might be nice to back that up with some sourcing.  Troops were being shipped from Europe to Asia.  There was a massive build up underway in Okinawa of troops and landing craft.  That's a lot of trouble to go to for an invasion that wasn't going to happen.

Similarly with the expected casualties.  Incidentally I've read 500,000 dead and 3 million total casualties.  If you claim this was ex post propaganda a source would be nice.

The Japanese *government* was not putting out peace feelers.  A faction in the government was.  And keep in mind the hawks in the cabinet, without whom the government could not make decisions, were in favor of continuing the fight *after* the bombs were dropped.  It took the totally unprecedented intervention of the emperor to break the deadlock.

That's not a government that was ready to surrender without the bombs.

And you say you're not talking about morality, but what is your claim that the US purposely nuked two cities to jockey for post war advantage?  Morally neutral?

[grumbler]

Although weren't they effectively on the same day, because the Soviet entry into the war was probably a surprise as it's likely that Sato couldn't communicate with Japan? Sato was informed on 8 August that the USSR would enter the war "tomorrow" on 9 August. The meeting with Molotov was at about 5pm Moscow time and continued for a bit. Sato asked for permission to inform Tokyo before midnight, which Molotov agreed. But Sato didn't clarify which timezone the state of war would start in - the USSR invaded at midnight Transbaikal time (six hours ahead of Moscow). So Sato only had less than an hour from his meeting to wire Tokyo, if the Soviets would let it out in any event. Given that Molotov's declaration said that the Soviet Ambassador in Tokyo would be simultaneously informing the Japanese government - which didn't happen it feels likely. The Japanese only became aware of the war through the invasion along the entire Soviet front at 4 am - and just a few hours before Nagasaki. Not allowing Sato to communicate/using timezones like that does also accord with other behaviour by Stalin and Molotov.

The Soviet offensive became known to the Big Six, as you say, early on August 9th.  They met that morning (and Suzuki met with the Emperor) but the Big Six was still deadlocked.  The Army even began secretly preparing to declare martial law and take over the government.

Doesn't that depend on which communication from the Emperor you look at - the communication to the soldiers and sailors which does the opposite. It mentions the USSR but not the A-bomb. I believe Hasegawa's thesis on the Emperor is that the entry into the war of the USSR presents a far greater threat to the imperial throne and household (and raises the risk of Communist revolution as well as territorial losses) and tilts the balance for him towards surrendering to the US. The cabinet secretary's documents also refer to both.

The Emperor's radio message noted that "Moreover, 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.   Should we continue to fight, it would not only result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization."  It did not mention the Soviet DoW.


And I think he also quote Kawabe from the command which does give a sense of the double shock effect on Japan:

When the atomic bomb was dropped, I felt: "This is terrible." Immediately thereafter, it was reported Soviet Russia entered the war. This made me feel: "This has really become a very difficult situation."

Russia's participation in the war had long since been expected, but this does not mean that we had been well prepared for it. It was with a nervous heart filled with fear that we expected Russia to enter the war. Although it was a reaction of a man who was faced with the actual occurrence of the inevitable, mine was, to speak more exact, a feeling that "what has been most [feared] has finally come into reality." I felt as though I had been given a thorough beating in rapid succession, and my thoughts were, "So not only has there been an atomic bombing, but this has come, too."

I believe that I was more strongly impressed with the atomic bomb than other people. However, even then, ... because I had a considerable amount of knowledge on the subject of atomic bombs, I had an idea that even the Americans could not produce so many of them. Moreover, since Tokyo was not directly affected by the bombing, the full force of the shock was not felt. On top of it, we had become accustomed to bombings due to frequent raids by B-29s.

Actually, [the] majority in the army did not realize at first that what had been dropped was an atomic bomb, and they were not generally familiar with the terrible nature of the atomic bomb. It was only in a gradual manner that the horrible wreckage which had been made of Hiroshima became known, instead of in a manner of a shocking effect.

In comparison, the Soviet entry into the war was a great shock when it actually came. Reports reaching Tokyo described Russian forces as "invading in swarms." It gave us all the more severe shock and alarm because we had been in constant fear of it with a vivid imagination that "the vast Red Army forces in Europe were now being turned against us." In other words, since the atomic bomb and the Russian declaration of war were shocks in a quick succession, I cannot give a definite answer as to which of the two factors was more decisive in ending hostilities.

He can certainly quote Kawabe, but not to support the idea that the Soviet DoW was the straw that broke the camel's back.  And certainly not to support the idea that the a-bombs were unnecessary (if the US had had a crystal ball that would have told them that the Soviets would declare war two days after the first a-bomb was used).

And Toyoda recorded that while he felt the A bomb was a cause and it wasn't the only cause. The military felt the bomb wouldn't be regularly used (I think correctly, if the war had gone on). He noted that the Soviet invasion was a bigger shock because the military that would happen in autumn and it "became impossible for us to map any reasonable operation plan. Moreover, the peace program which we had so far relied on came to naught [...] I believe the Russian participation in the war against Japan rather than the atomic bombs did more to hasten the surrender." Obviously all of those are memories after the event - and it must have been an incredibly chaotic time just three days and Japan was facing two atomic bombs and massive invasion.

And Koichi Kido stated that "We of the peace party were assisted by the atomic bomb in our endeavor to end the war" and the secretary of the Cabinet statesd that the atomic bombings were "a golden opportunity given by heaven for Japan to end the war."

He could also quote Togo, who had a meeting with the Emperor on August 8th (so before the Soviet DoW) in which the Emperor stated that the government must find a way to immediately end the war.  The use of the atomic bomb had convinced the Emperor that there would be no invasion and thus no chance to defeat an invasion and enter negotiations with a victory in their hand.  While the Japanese army was convinced that the US could not have many atomic bombs because of the known difficulties in separating U-235 from U-238, the Emperor didn't know this (and the Army didn't know about the numerous plutonium bombs the US was making - twelve such bombs could have been used over the course of 1945).

But all of this just debates which of the two shocks was greater.  None of it supports he argument that "it was the Soviet entry into the Pacific conflict, not Hiroshima and Nagasaki, that forced Japan's surrender. His interpretation could force a new accounting of the moral meaning of the atomic attack" as Gareth Cook of The Boston Globe argues (presumably, the moral meaning of the Soviet violation of their treaty with Japan is not important).

[grumbler]

I never said anything about the morality of the atomic bombs. In fact I said that bombing cities was seen as acceptable at the time with precision bombing being a far future dream.

I've read that using the bomb on an unpopulated area was considered too but this doesn't really make sense. They'd already done that in the US and if they drop it on an unpopulated island then who is going to be around to see it? It would serve no purpose. It would also mean missing out on the valuable opportunity to use the bomb against an actual city and be able to properly analyse its damage.
I could be wrong but I don't recall any sources from the time actually proposing an unpopulated target, a quick google and I just find modern people saying it was an option.

Using the bomb on an unpopulated target was considered at the time and is mentioned, in fact, by Truman in his memoirs. He quotes the targeting committee as telling him "We can propose no technical demonstration likely to bring an end to the war.  We can see no acceptable alternative to direct military use."  Up your google game.

The bomb in no way saved vast numbers of American lives. Thats a nonsense. An American invasion of Japan just wasn't going to happen. The timelines just didn't line up for it. At the very least long before America got around to this the Soviets would have landed on Hokkaido and the need to surrender vastly stepped up.
The commonly repeated saving over a million American lives in an invasion thing incidentally is part of the post war propaganda effort to justify the decision to drop the bomb and claim its role as war winning wonder weapon. Its not based on contemporary estimates.

An invasion of Japan was unlikely, but your assertion that it "just wasn't going to happen" is based on your prejudices, not the historical facts.  The Honshu invasion was still the accepted plan when the bombs were dropped, even though some significant military leaders had turned against it.  I'd rate the chances of an invasion as low, but can't see a justification for an assertion that it was zero.

The "commonly repeated saving over a million American lives in an invasion thing" strawman is commonly repeated, but bears no resemblance to any informed argument on the topic.  The Soviets were not going to be able to invade japan in 1945.  They struggled mightily to invade southern Sakhalin by sea, and were , in fact, being pushed back into the sea when the Japanese surrender came.  A large -scale Soviet amphibious capability was years away.

Even sans the bombs Japanese surrender wasn't far off. They were already putting out big peace feelers, the only sticking point was that they wanted to talk (as was the norm) whilst the allies insisted on an unconditional surrender... And it was basically just fear of something happening to the emperor which was Japan's main sticking point there.
Also its notable that when the decision to drop the bombs was made Japan hadn't yet gotten the memo from the Potsdam declaration that unconditional surrender was the only way to end the war. Again this points towards the Americans being really keen to use the bomb rather than it being a weapon of last resort.

The Japanese were not, in fact, "putting out big peace feelers" and, sans the bomb, their surrender was a long ways off.  Among themselves (but not to the Allies) they discussed pace conditions, but those included absurdities like no war crimes trials except by the Japanese themselves, no disarmament of the military, no occupation, etc.  Also, it is notable that the Potsdam Declaration changed nothing and introduced no new terms to the Allied demand for surrender.  It was a reiteration of demands long made.  Again, this points towards a faction that is really keen to misinterpret the history of the use of the atomic bombs in order to be able to make feel-good moral judgements about others.

[OttoVonBismarck]

As far as I can tell, and I've read literature from the likes of Gar Alperovitz and other anti-bomb adherents, that you're not really off base berkut. They start with the predicate that the bomb must not have been necessary, and to support that predicate they need to find clear and convincing evidence that other alternatives were less cruel.

Alperovitz advocated for simply doing an endless Naval blockade. The issue that ignores is that, as grumbler mentions, a society hits a certain point of starvation--when basically all food supplies are gone and they can only keep going off of what food they are actively producing, where people start to die of actual starvation. Famines, once they really get going, can chunk out huge percentages of the population. It's not at all crazy to speculate that Gar's preferred method could have reduced the population of Japan by 30% or more, but hey, we'd be able to say we hadn't dropped the bomb.

The Soviet invasion argument is more tortured, because it says that one, Japan absolutely just surrendered because the Soviets invaded--thus meaning our bombing of Hiroshima and Nagasaki was pointless and evil; but it also speculates somehow we should have known the Japanese would surrender the moment the Soviets invaded--since the timeline was that we bombed Hiroshima before the Soviet invasion and Nagasaki essentially concurrently to the Soviet invasion. There are two big holes in the argument, one is there is scant evidence to suggest that the Soviet invasion sans atomic bombings would have lead to surrender. There's some contradictory evidence that maybe the Soviet invasion was the final nail in the coffin, but it's impossible to know from real history that it would have been enough without the atomic bombings, because the atomic bombing of Hiroshima had already occurred and was well understood by the Japanese at the point they made their decision. It stretches credulity to believe the specter of even more atomic bombings didn't factor into Japanese decision making, not only does it stretch credulity, it defies some of what we know from the historical record of Japanese deliberations.

The other big hole is assuming the Japanese feared Soviet invasion dramatically more than American invasion. I think that assumes some things, for one the Japanese knew the Soviet naval forces were not very impressive, and the Soviets had much reduced capacity to conduct a large scale naval invasion than the United States. Keep in mind what the Soviet amphibious activities really were--one, a landing in Northern Korea by about 15,000 troops, and another landing in Kuril of about 6500 troops. Remember that Sakhalin Island was actually split between Russia and Japan after the Russo-Japanese War, so Russia was better positioned there because it could build up ground forces on its side of the demarcation line. Thus, Russia activities in both respects, were relatively small. The Soviets had considered invading Hokkaido and called it off, because that was a much bigger Naval and amphibious landing undertaking. While some of the Soviet reticence was that the invasion of Hokkaido would be a blatant violation of the Yalta Agreement--and Truman had already specifically saber rattled that he would have found any Soviet occupation of the home islands unacceptable, it's impossible to deny that the Soviet military planners also were expressing grave doubts about their ability to carry out what would have been almost an Operation Overlord scale naval and amphibious invasion, but with a far less powerful and capable naval force than the combined American/British fleet had in Western Europe. Frankly the Soviet invasion plans were grim, due to their limit in transportation and landing craft the "invasion wave" would actually have to land, have transport ships cross back over, pick up more guys, and then land again. Meanwhile the first wave would be facing pretty terrible fighting. This was in stark contrast to Overlord, while we sent in landing craft in multiple waves, we had 132,000 soldiers landed on the beaches of Normandy on D-Day, with another 24,000 who had landed as paratroopers.

It is highly unlikely Japan was unaware of how weak the Soviets were at sea, and how difficult a truly large scale amphibious invasion would be for the Soviet Union. I find it skeptical that the Japanese credibly believed the Soviets were going to overrun the home islands when they still thought they had an ability to massively resist and slow down a U.S. invasion of the same, given they knew the U.S. had the world's largest Navy by that point and a massive number of support capacity for doing amphibious invasions.