Alex WellersteinVerified account

Forecasts of bad weather pushed the Hiroshima date forward, and similarly pushed Nagasaki back, removing that interval. As a result, the Japanese high command were only just getting hearing of the reality of Hiroshima (they sent scientists) when the 2nd bombing mission started.

It says that the first bomb "of tested type" should be ready by 6 August, and the second one around 24 August. A big interval... if you don't realize that there was another bomb, the "untested type" that was dropped on Hiroshima.

Truman was pretty removed from the atomic bomb work. He also had a lot on his plate at Potsdam. He got totally fixated on the Trinity test, and I don't think he realized there were going to be two bombs ready in early August. All planning discussions were about the first use.

(Truman's personal role in the bomb decision, per General Groves, was "one of noninterference—basically, a decision not to upset the existing plans." He was told many of the plans, but it's not clear he totally understood them, or the details. Again, he had a lot on his plate.)

(The idea that Truman "decided" to use the bombs is an after-the-fact story that Truman and others liked to tell, to make the use of the bombs seem more deliberated over than it was. Many other people made decisions, but Truman himself participated in very few of them.)

Separately, most Japanese archival evidence shows that the Nagasaki bombing did not materially have an effect on the Japanese high command, either. They learned about it during a meeting they were having to discuss Hiroshima and the Soviet invasion.

This was the same meeting where they decided to put forward an offer of conditional surrender (which the US rejected). There isn't any evidence that the Nagasaki attack changed anyone's point of view in that room.

Absence of evidence is not absence of effect, but it clearly wasn't a crucial part of it. The idea that the Japanese didn't believe that the US had more atomic bombs is mostly untrue. If Nagasaki hadn't happened, it seems likely that little would have changed regarding surrender.

This is why many people who have studied it have found Nagasaki not that justifiable. Ted Telford, the chief US prosecutor at Nuremberg, concluded that had had "never heard a plausible justification of Nagasaki."

I think one can come up with "plausible justifications" for Hiroshima, even if they are debatable. Nagasaki is definitely a trickier moral issue, if your concern is with not slaughtering masses of civilians unnecessarily.

(If your argument is, "the Japanese [people] were evil and deserved it," then clearly the issue of plausible justification isn't an issue for you. I always get many replies to this effect.)

(I understand where they are coming from, especially from people who are from countries brutalized by the Japanese military. I don't think that justifies targeting children, as I've written on here before. But I understand it.)

Anyway, the most important consequence of Nagasaki, in my opinion, was that it greatly disturbed Truman. He had just gotten the casualty reports from Hiroshima and was already unnerved. He didn't know another bombing was going to happen so quickly. His attitude quickly soured.

Truman's reclamation of authority, and insisting that all further nuclear use orders be routed through the President (and not the military), changed the nature of US nuclear weapons going forward. He reinforced this many times in his later presidency.