Well, ok, this is inappropriate for the overall topic here, but since you're not sure what my point is...

Since WWII, wars of conquest have been rather rare and have not so far grown to the scale as to even appear to justify, in any way, the use of anything like nuclear weapons. World War II, as it is known in the US, was different.

The Empire of Japan had been engaged in an aggressive war of conquest since 1937 (or possibly 1931, depending on how you look at it). (I did mention the death toll in China, right?)

The United States was engaged in a justified war with the Empire of Japan in 1945. (Do you dispute that?)

Both countries were engaged in total (or absolute) war, meaning that both had fully engaged their economies in the war effort. (This is important because, under total war conditions, the civilian economy is a legitimate target of war. Practically speaking, not doing so leads to World War I, a lengthy military stalemate, and the eventual collapse of governments and other ... bad stuff. I admit this is a personal moral viewpoint. On the other hand, fine logic chopping over the ethics and legality of warfare is pretty irrelevant. War is evil.)

The terms under which the Empire of Japan was willing to surrender were essentially that the military government of Japan be allowed to continue unmolested.

In August, 1945, the United States had two (2) options:

1. Invasion of the Japanese Islands. Two things of note: The Battle of Okinawa (which ended the previous month), involving (according to Wikipedia) ~75,000 Japanese soldiers and ~40,000 Okinawan conscripts, resulted in the deaths of between 40,000 and 100,000 civilians, or between 10% and 30% of the islands population. The Imperial Japanese Army had ~900,000 soldiers in Kyushu.

2. Continue with the blockade of the Japanese Islands. Many authors suggest that by 1946, this would have led to the deaths of millions of Japanese civilians. Christopher Clary (https://journals.wichita.edu/index.php/ff/article/download/6...) makes a pretty compelling argument that they were not very near starvation, so there's that. He also quotes,

"Early surrender? With no atom bombs, no Russians, no invasion? Careful inspection of the "testimony of the surviving Japanese leaders involved"--even that incomplete sample available to the USSBS during its two short months in 1945--shows only [Marquis] Kido [Koichi, Lord Keeper of the Privy Seal] supporting Nitze, everyone else [including more than twenty other high level officials] stating that Japan would have fought on indefinitely. When would Japan have surrendered without the bomb and the Russians? The only credible answer is that given by Robert Butow when Freeman Dyson asked him about it: "The Japanese leaders themselves do not know the answer to that question.""

In any case, both options would have included continued strategic bombing (see also Operation Meetinghouse), of which the use of atomic weapons was an extension (no, really, check out Operation Meetinghouse). The use of large scale bombing of civilians had been settled far, far earlier in the war.

As a final point, consider a role playing exercise: Put yourself in the position of a US government or military official explaining the decision not to use some weapons at your disposal, because they were too horrific, to the mothers of US soldiers who had been killed in subsequent fighting. To criticize someone for (not) doing something, it has to have been possible for them to not do it (or to do it).