Alex WellersteinVerified account

Anyway. In July 1945, Truman knew for sure (because of the Trinity test) that the US had a workable atomic bomb. He also knew that Stalin was planning to renounce his neutrality with regards to Japan, and invade by mid-August 1945, because Stalin told him this.

The Americans AND the Japanese, as an aside, both considered a Soviet invasion to be a likely tipping-point for Japanese surrender. The Japanese army knew that they lacked the forces to repel an invasion by the USSR, and that Stalin didn't care about trading blood for territory.

(I only point this out because it was only about a year ago that I learned they had actually been analyzing this scenario for months before it happened. Some accounts make the Japanese military seem quite ignorant of the possibility, but it is very clear they were not.)

It is clear that Truman had a vested interest in trying to use the bomb ASAP, because he was hoping that the war might end before the Soviets got involved. Why? Because he had seen in Europe that where Soviets liberate, Communism stays behind.

Stalin, as mentioned, had an incentive in being in the war, because he would get several juicy bits of territory as a result, in particular the full island of Sakhalin and the Kuril Islands, which gave the Soviets easy access to the Pacific.

(He even contemplated taking the Japanese island of Hokkaido, but was convinced by his advisors that this could be a deal-breaker with the USA.)

Anyway, this is the context. Truman agrees that the first atomic bomb should be dropped as soon as possible after the Potsdam Conference ended — hoping to preempt the Soviets, e.g. August 3rd or so. Weather conditions delay that until the morning of August 6, 1945.

The bombing of Hiroshima occurs, as we know. It was militarily a very successful operation: the city itself was totally disabled by it. This included, incidentally, its ability to communicate easily with the outside world.

The Japanese high command basically did not know what had happened until the morning of August 7th, when Allied propaganda channels broadcast Truman's statement about the atomic bombing. The Japanese high command met on August 7, and decided not to act until they confirmed it.

Just as a note: It's not crazy for them to want to confirm it before believing it completely. World War II was full of propaganda and misinformation by both sides, and claims of fantastical weapons were very common. Sending their own scientists before acting on it was reasonable.

Because of the disruption of the war, and the bombing, this took some time. It wasn't until late on August 8th that the scientists confirmed that Hiroshima was destroyed: "I'm very sorry to tell you this... the so-called new-type bomb is actually an atomic bomb." (Yoshio Nishina)

Back in Moscow, the Soviets had just granted the Japanese ambassador a long-desired meeting with Molotov. Molotov immediately handed him a declaration of war, saying it started "tomorrow." But he was used a different time zone for "tomorrow," so it started in a few hours. Tricky!

So at midnight on August 8/9, Soviet forces stream into Manchuria, overwhelming the Japanese there. The Japanese high command put together a meeting the next morning (Aug. 9). They are clearly VERY distressed by the Soviet situation, and are trying to figure out what comes next.

Now, did the news they had gotten about the Hiroshima bomb play a role in their distress? Maybe! It's VERY hard to disentangle the two. The news of both overlaps in a very real way. There are those who will argue for one or the other being more important. It's a hard call.

Either way, the Japanese high command, including the militarists, are despondent. Things are NOT going well. The "bleed them out" plan won't work against Stalin. Obviously Stalin isn't going to negotiate a diplomatic end of the war for them, either. And the US has atomic bombs.

During this meeting, the bombing of Nagasaki happens (11am Japanese time). The news is brought to them during the meeting. It does NOT seem to affect the conversation in any strong way — the opinions they have prior to learning about Nagasaki don't change.

This is why historians tend to say that Nagasaki wasn't that important; there's no evidence of change. Could it have added to existing convictions? Maybe. Can we re-run history without it, to see what happens? Obviously not. But it doesn't seem to have done much at that meeting.

Hence there are even historians who think that the Hiroshima bombing was necessary, but Nagasaki was not. The "after the fact" justification of the two bombs, as an aside, has nothing to do with why Nagasaki happened when it did.

The original plan was to wait until August 10th (after the August 3rd plan for Hiroshima) before the second bomb — a solid week between them. As it was, it was only 3 days. Nagasaki got moved up because of weather considerations, just as Hiroshima had been moved down.

And it is just worth noting that while the Hiroshima bombing was very carefully planned, considered, etc., Nagasaki was — as I mentioned before — something of an afterthought. Truman was not informed about it happening; I don't think he really knew.https://twitter.com/wellerstein/status/1027546489302798337 …

Anyway. The end of this meeting of the high command was the decision to offer a conditional surrender. The August 10th surrender offer was basically to accept the Potsdam terms so long as they didn't prejudice the position of the Emperor. AKA, a condition.

The US rejected this — unconditional meant unconditional. There are complex reasons for this, but one was that the US hadn't really decided what it would do with Hirohito yet. (They ended up letting him stay on as a figurehead.)

At this point I just want to add: even two atomic bombs AND an invasion by the Soviets was not, by itself, enough to convince the Japanese to embrace unconditional surrender. That's how tough the "unconditional" desire was! They were willing to give up a lot, but not the Emperor.

While the US kept up conventional bombing, within Japan there were deep divisions about what to do next. There was an attempted coup by junior officers opposed to surrender, which was put down. Finally, on August 14, Hirohito personally intervened and agreed to "unconditional."

Different historians give more or less emphasis to different aspects of this, but I think the above is mostly uncontroversial as a timeline. The controversial stuff are the interpretations. Was Hiroshima necessary? What about Nagasaki? Would the war have ended without either?

I'll note, as an aside, that the US invasion of Kyushu was not to start until November 1945. Some accounts make it sound it was going to happen the next day or something, that it was barely avoided. This is wrong; there were 2 more months there.

Personally, I think the balance of evidence points against Nagasaki playing a big role, but the "mix" of Hiroshima and the Soviet invasion is tough to disentangle. There's evidence that the Soviet invasion mattered a lot. But that's not the same as saying Hiroshima didn't.

What I do think a balanced account of the timeline indicates, though, is how inadequate the simplistic "two bombs and surrender" version of the story is. It's much more complex than that, much less straightforward, and doesn't lean into easy propaganda one way or the other.

Bottom line: if your vision of historical events tends to render your historical conclusions as being very simple (and coincidentally they overlap with your present-day political views), you're probably leaving a lot of important stuff out. Real history is complicated and messy.