A couple of counter points to add to
@BimboColesHair 's point.
Well, we did have quite a few projections with respect to progress in the war, particularly in late 1944, early 1945. It was the majority opinion of the American military command that Japan would surrender (without invasion), no later than November 1945.
When consulted, General Eisenhower had strongly advised
against the use of nuclear weapons on the basis that it was completely unnecessary; the Japanese were going to surrender
without a land invasion -
"they had already been defeated."
Again, I don't think we can simultaneously acknowledge the fact that the Japanese were motioning for surrender,
repeatedly since January, and that the American government was aware of this; while then considering the complexities/difficulties of invading the main islands of Japan.
What exactly would we be invading for? To depose the Emperor, and that's it?
So this brings us back to the more likely, and more historically accurate (imho) opinion, that the United States dropped the atomic bombs on Japan for the aforementioned reasons by myself and
@BimboColesHair .
I think it did. For the reasons
@King Stannis pointed out; the United States likely would have weighed the lives of the Germans a bit differently than that of the Japanese.
Let me walk you through my logic on this.
1)
If we accept that the bombings were purely political, and not of any military necessity; then we must evaluate the decision to drop the bombs within only that context.
2) To have killed hundreds of thousands of defeated Germans using nuclear weapons, would have not nearly as resonated as well within American or European civilization; due to the Japanese being viewed as subhuman, merciless animals.
c) Given these views, it's apparent how the Administration was more inclined to drop the bomb on the Japanese, even though the Japanese were already defeated. This same decision is less likely to be made against White Europeans in the heart of Europe.
Again, I think this ignores the very real, yet less publicly known realities of the war.
While yes, the Japanese put forward a policy of "fighting to virtually the last man," America knew that the Japanese had made numerous overtures to the Soviet Union, the Vatican, and the OSS to mediate a surrender that would allow for the Emperor to avoid prosecution and subsequent execution.
Again, as early as January 10, 1945, the Americans knew the Japanese
wanted to surrender, and when we issued the Potsdam Declaration, it is widely acknowledged that the President had literally no intention of the Japanese accepting the terms prior to the bombing of Hiroshima and Nagasaki, which ultimately, they never did.
This has been documented by numerous historians going back to 1946.
Lastly, I think the dichotomy you present here never actually existed.
As documented by Gar Alperovitz, historian Martin Sherwin points out Truman's decision-making process (and the absence of any real need to use the bomb):
"...not the lack of an alternative that might induce Japan's surrender that led to the use of atomic bombs. It was the undesirability of relying on the available alternatives given the nuclear option (emphasis his).
The nuclear option was preferred because it promised dividends— not just the possibility that it would end the war but the hope that it would eliminate the need to rely on one of the other alternatives."
"(the) choice in the summer of 1945 was not between a conventional invasion or a nuclear war. It was a choice between various forms of diplomacy and warfare."
"While the decision Truman made is understandable, it was not inevitable. It was even avoidable."
I've kind of veered away from the point of racism, but will only backtrack in order to point out the decision making process had far less to do with the military considerations of invasion, and instead, the use of this destructive weapon as a political tool.
I think once one accepts the argument that there was no military necessity to the bombing, then one has to entertain the quality that race introduced into the equation.
Moreover, the Los Alamos scientists largely felt race was indeed a component in dropping the bomb over Japan and largely opposed the idea.
I agree with you here with respect to the invasion of Europe. But by 1945, the Soviets were actually stalling the Japanese peace negotiations in the hopes of conquering territory in Southeast Asia and hopefully Japan itself.
So the calculus here is quite different, I think.
But with respect to the original question, Eisenhower was adamantly against the atomic bombing of Japan for exactly the reason you just described. It was not of military necessity and was, in his view, highly immoral.
We know the primary intent of the Japanese from late July was to surrender; and we knew prior to dropping the bomb on Nagasaki that Japan was making motions to do just that.
We also knew that the Japanese would have surrendered to the United States prior to any Soviet invasion from decoded communiques that we had been capturing for quite some time.
A major factor? No. Definitely not.
MacArthur and Eisenhower both felt that Japan was defeated and the atomic bombings were unnecessary. Neither thought an actual invasion was necessary or warranted given that it was widely known that Japan wanted to discuss terms for surrender.
The OSS had advised the Administration that Japan had absolutely no intention of letting the war drag on, and desperately wanted to avoid any possibility that the USSR would invade the main islands of Japan - even if that meant surrendering to the Americans.
The OSS advised the Administration that in early May, Japan had made overtures to Portugal to surrender and removed any conditions save one. The only condition for surrender was the retention of the Emperor.
Given that the Potsdam Declaration was ambiguous enough so as to delay the ending of the war (to which both Churchill and Stalin opposed), it's fairly obvious the intention of the Truman Administration at this point.
So given this, and given the fact that the Emperor was ultimately retained. What does invasion actually accomplish?
So, to answer your question, I don't think invasion really was considered a likely scenario. There was no dichotomy of choices between dropping the atomic bombs and a land invasion; I think that's a popular belief, but it's not really based on historical evidence.
Roosevelt was open to the idea of a public display of a test shot for the Japanese and Soviets to witness.
Marshall argued the decision to use the atomic bomb (i.e., the destruction of an entire city) was entirely political and he should not be asked one way or the other. He advised the weapons be used tactically against military targets. He also advised the Soviets be made aware of the weapon and be present during the Trinity shot; which was dismissed out of hand (again, intent here is important).
Truman on the other hand, had very different intentions. By 1945, Truman felt the primary enemy would soon change from the Axis to the Soviets; and he wanted to contain communism as much as he possibly could.
A couple of problems with this argument.
1) This argument ignores the fact that on July 25, 1945, the United States strategic goals in Japan changed. Urban centers were not even tertiary-level targets of interest. Japanese infrastructure had already been decimated, famine was rampant, and most military targets had already been highly damaged.
2) The United States was not likely to continue heavily bombing Japan prior to the scheduled November invasion.
3) By this point of the war, Japan lacked significant capacity to defend it's airspace, so the risk to American aircrews was minimal.
4) It was not believed that the atomic bombs would actually change the real terms of surrender; and, they did not. The terms had not changed since May.
5) The United States knew that Japan would surrender only if the Soviets were poised to invade, or, if the United States assured the safety of the Emperor.
6) The Japanese proposed the ultimately agreed upon terms, and had the United States accepted, the war would have ended in 4-5 months earlier than it did.
7) Henry Stimson, Secretary of War at the time, recognized that the United States' policy of "unconditional surrender" ultimately and unnecessarily cost the lives of hundreds of thousands of people while achieving nothing either militarily or politically.
8) The Soviet invasion of Manchuria, and the subsequent invasion of Southeast Asia (which ultimately would lead to the Korean War) would almost assuredly never have happened had the United States not prolonged the war solely to use the atomic bomb.
9) This argument ignores the likelihood that the Potsdam Declaration was deliberately worded so as to prolong the war.
Lastly, I'll quote the US Strategic Bombing Survey (July 1946)
"Based on a detailed investigation of all the facts and supported by the testimony of the surviving Japanese leaders involved, it is the Survey's opinion that 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."
So, to answer your question again; no, I don't think the dichotomy of choice existed between invasion and the dropping of the atomic bomb. I think that's an oversimplification and even romanticized view of the realities that were involved and the positions of the parties advising the President.
This is often cited as a reason to justify the attacks; just want to point out a couple of things.
Tokyo is an ancient and massive city. It's size is really hard to appreciate; but, during the height of the war going back to 1944, the population of Tokyo was 6.8M. This was a city that was built primarily out of wood. In fact, much of the older parts of the city were considered extremely flammable.
This was known to the United States prior to the firebombing of Tokyo; and this was a concerted strategy - the de-urbanization of the population there.
These firebombing raids which killed upwards of 200,000 people; as horrible as they were, are not really directly comparable to the nuclear attacks on Hiroshima and Nagasaki.
Those bombings decimated those cities completely, killing, maiming or displacing more than half of each of their populations. A subsequent September nuclear attack on Tokyo would have killed an estimated 1.1 million people outright.
So, in short, I think people misunderstand the scale, population density, and size of Tokyo compared to Hiroshima and Nagasaki. Had those weapons been used in large population centers, the extent of death would have eclipsed the previous bombings.
1) The firebombings of Tokyo weren't easily repeatable for the aforementioned reasons.
2) It is odd to argue the blockade was less humane that the nuclear attacks; don't you think?
I understand what you mean, but, I don't think there is
any evidence of this conjecture being true given the United States clearly planned to occupy and retain Japan.
But that was not the purpose of the announcement. The public announcement was made so that (1) Hirohito could end the war without any fear of a coup d'etat overturning that decision, possibly imprisoning him (2) because only the Emperor could get the people to understand that the war must end, and it was not a matter of interpretation.
It wasn't the decision of the Allies to have the Emperor speak, it was his own, and that of his advisers.
Again, I really don't think this conjecture is evidenced by the facts that we know of.
Getting back to the original question, within the context of these facts, the bombings certainly seem political, IMHO. While one could attempt to make an argument of necessity, I don't think that's really the strongest argument here, from an historical standpoint; so leaving biases aside, I'm not sure why we would accept that conclusion over the more obvious one.