The debate is not between a united front of participants at the time (plus you) and later critics that you wanted to paint as philosophically unreasonable. It was a live issue at the time, and the correct position was seen and advocated, by clear sighted, rational men holding the gravest responsibility. It just wasn't acted on.
Next reading comprehension. Good faith in negotiations is a term of art that means making demands that are one's actual demands, making them openly and plainly, being as good as one's word, and expecting the same. It means agreement is the actual goal of the negotiations, not playing to a gallery or other extraneous goals. It is usually contrasted with negotiating in bad faith, marked by taking positions that are not one's own policy demands, purely for bargaining purposes; holding out things one doesn't want as bargaining chips, negotiation purely for show and consumption by third parties rather than seeking agreement with the counterparty, deliberate "crossing" behavior of asking not for what one wants, but what one expects the counterparty to be reluctant to give, and the like.
It was in bad faith to demand terms that implied removal of the emperor when there was no need or intention to remove the emperor. It was done for the sake of third party consumption (the electorate, the Russians), and for glory or the appearance of power or of consistency - to appear not to need to negotiate.
What I called "implacable self righteous" is exact and means somehting, it is not a free floating denuncifier. The desire to appear implacable means "cannot be placated", means "will not negotiate". Men may feel a subjective sense of power in it and third parties may even so perceive it, but it is not a source of power itself. It consumes it, spends it. Power gets what it wants and minimizes and neutralizes opposition effectively.
An accepted ultimatum would not have ended the war any less effectively. A rejected one that had been more reasonable and in better faith, would not have precluded the course of action actually taken to win the war.
What you call "situational pursuit of peace" is simply the moral and reasonable demand that the aims of war be kept constantly in view throughout its course, and the continuation of war be subordinated to achieving them. This is in contrast to war for its own sake, war as punishment, war to annihilate the adversary rather than achieve his compliance and one's own political aims. It is the subordination of war to political direction and rational control of that direction for civilized ends - in contrast to, say, a deliberate war of annihilation as Germany proclaimed in Russia, to pick an example.
The US wanted Japan to cease hostilities and to submit to occupation and demilitarization. If it could achieve those ends with less loss of life and no cost to their actual achievement, it had a clear duty to do so. If that depended on the Japanese as well (it did), then the US's duty in the matter was limited to offering that outcome in good faith. It would then by Japan's duty to accept it, on recognizing that keeping the emperor was the only political aim for which they were fighting that the allies would conceed in practice, and that their military situation was hopeless.
Ambassador Grew and Stimson saw this, and Stimson in particular also clearly saw the gravity of the ultimatum. He knew what the atomic bomb meant, not just for the end of that war. As for what knowledge of Japan was behind their proposal, Grew knew Japan better than anyone else involved in the US decision making process. He knew what the emperor meant to the warrior code of the Japanese military. He knew how futile it was to threaten them with a destruction they gloried in accepting, compared to appealing to a point of honor. Stimson heard him out, and gave his mature judgment - among the best ever to serve the United States or any great power, on every sort of subject, I might add - that a clause saying the emperor could remain if Japan laid down arms, would materially increase the chances of the ultimatum being accepted.
There is every reason to believe that judgment is correct. It would have materially increased the chances of the ultimatum being accepted - without raising them to certainty, admittedly. It cost nothing, and it had a significant chance of saving the lives of half a million human beings.
It was wanton to reject that advice. Stimson was right, and Truman was wrong about it.
You really can't comprehend an actual disagreement, can you? You really think that by deluging me with pre-selected definitions, and wrapping them into targeted premises, I won't notice what you're doing. And as for your cheap insults, why bother writing so much if I'm too stupid to understand you? Well, put your wagging finger down. I know your position clearly, and it is wrong.
You deify Stimpson, but you don't go into why he was overruled. On the one hand, he wanted to seek a way to avoid the use of the bomb by allowing the emperor to stay on the throne. On the other hand, this same peacenik ordered the bomb to be used with utmost savagery when it was used. But you cite him as merely being overruled.
How convenient. But the fact is that Stimson went along with his overruling willingly, and only sought to distance himself from the decision when he wrote about it after the war, when people were horrified by the bomb. But Stimpson wanted to win the war with the least possible American deaths, and as you acknowledged fought like hell to accomplish this task. So is it too much to ask that you use your big brain to wonder, just a little bit, what the argument was that got him to so enthusiastically get behind using the bomb?
Your juvenile invocation of good and bad faith might ring appropriate for a civil suit (but only if you've never met a lawyer). However in cases of what amounted to total war, it is the height of naivete'. You invoke the total war of Nazi Germany, but despite all of your verbosity leave out the firebombing of Tokyo and virtually all of the big cities in Japan, or the Japanese slaughter in China or the Phillipines, or their notorious sadism everywhere they went. How convenient for you to forget such extremities, especially since it allows you to invoke "negotiating in bad faith" during such a total war as not being up front with the enemy by being plain about your goals during discussions?
What a puppy you are - at least I hope you are. Otherwise you are clearly aware of your own lack of foundation, and are disingenuously scrambling to hide it. For these are people who, at that point in their history, would cut off your head, and those of your family, rather than talk with you at all - and tell you you were beneath humanity if you didn't die fighting them, because you wanted to negotiate rather than fight to the death! Hello? Do you get that?
That's why I invoked Bushido, but apparently it was "too simple a concept for you to understand." What was explained to Simpson, and what he not only went along with, but helped with it's savagery, was that the Japanese people of the time needed to be broken. Otherwise there would never be genuine peace with them, because they were driven by delusion.
That was why their fighting spirit itself, their belief in themselves as superior masters of the human race, their divine justifications for all of their rape and slaughter - in other words, the driving force behind their fighting - must be utterly destroyed. And the only way to do this was precisely to force their unqualified surrender with their own offering of their emperor. Nothing less would do, by their own value system.
You mock our allowing the emperor to remain after our use of the bombs and their resulting unqualified surrender, as if it brands us as hypocrites. But you just show your own ignorance - it was the offering of their emperor that was their moment of true collapse. Our offering of their emperor back to them was compassion on our part, as the issue was no longer a threat to us. Ask any Japanese person about the shame of having to offer their emperor to sue for peace - the offer was the key thing. that was what finally broke their arrogance.
You say Stimpson "knew how futile it was to threaten them with a destruction they gloried in accepting, compared to appealing to a point of honor ...that a clause saying the emperor could remain if Japan laid down arms, would materially increase the chances of the ultimatum being accepted."
Yet history shows you to be dead wrong - the two bombs broke these supposed "people of honor," who were actually delusional sadistic cowards, and had them groveling so hard they offered their emperor in order to escape the total destruction they loved to bray they would gladly accept. And that was why the bombs had to be dropped - to show the Japanese people themselves that they were self-deluded liars, that they were human beings like all of the other human beings on the planet, and that their reliance on sadistic brutality, force and murder was not something they lived above, but which could and would crush them just as they crushed others.
And most importantly, that they had no "divine protection" from such complete destruction, and so any belief in such protection was false. that was what Stimpson was told must be done to get "peace" from the Japanese, because - as Simpson well knew - that was the invincibility Japanese believed about their inner strength that allowed them to pursue war so savagely, and without any remorse whatever.
And that is what Stimpson finally agreed with, and why he then not only advocated using the bomb, but using it as savagely as possible. Because though the Japanese might have agreed to a surrender without the bomb, they still would believe that they had fought with honor - and they had not. Do you understand? Your equivalent morality does not apply - it is wrong. The Japanese did not fight with honor, or for honor. They were depraved. And because of that, they could never be trusted in any qualified surrender, and would have inevitably rebelled against America again. Their demented definition "honor" would have required it.
Stimpson came to understand this, and that's why he agreed with his overruling, and enthusiastically supported the most savage use of the bomb as possible - to save millions of American and Japanese lives.
And it worked. Japan has completely rejected their murderous, militaristic arrogance, and instead channeled their energies into peaceful, truly admirable world-class business concerns. And why? Because at that time, and for the correct reasons, breaking them to themselves was the right thing to do.