It's not that the answers are morally good, but rather if you're already in a world war then the ethical part (diplomacy) has already failed and it's just going to be the degree of horrific things, not their absence, that we have to plan for.
Targeting civilians in places like Tokyo or Dresden didn't even help the war cause much. The Soviet Union defeated the Nazis without mass bombings of German cities.
Yes war is the supreme crime and what we should avoid in the first place. Still there are different ways you can conduct war.
A nuclear exchange would necessarily target civilians and be unlike anything before in history. It's a nightmare scenario that has to be opposed at all cost.
In our shared reality(?) the Soviet Union defeated the Nazi's in parallel with the mass bombing of industrial areas, factories, ports, dams, and general war making infrastructure, much of which was within German cities.
The Soviet Union defeated an increasingly under supplied resource starved German military.
What does "civilian" mean when it comes to Imperial Japan?
* https://www.nationalww2museum.org/war/articles/there-are-no-...
The official Japanese plan to defend against a US landing was to have children attack the invading US soldiers:
* https://www.hiroshimapeacemedia.jp/?p=141048
* https://apjjf.org/mark-ealey/1689/article
* https://en.wikipedia.org/wiki/Operation_Downfall#Operation_K...
You're reading from a curiously misinformed understanding of history. The USSR defeated the Nazis by killing millions of them while also burning, bombarding and destroying their cities and anything else in its way en masse during a ferociously bloody campaign of revenge mixed with genuine military imperatives. Soviet soldiers also committed what are probably some of the biggest mass rape epidemics in modern history against their German enemy's women once they entered their territory. This in particular was immaterial to Soviet victory and not an official Soviet policy, but I mention it to underscore that there was absolutely no shortage of war crime-worthy targeting of civilians in many ways, and on a colossal scale by the Soviets too.
Read about the invasion and ethnic cleansing of East Prussia if you like. At least couple hundred thousand German civilians died as a result of that alone. None of this at all compares to what the Nazis did during their eastern conquests of course, but while a war crime is a war crime, degrees exist. Thus, it's not surprising if allied moral and military conduct was on a very long leash given such extremely savage enemies as Germany and Imperial Japan.
Who says they aren't called it? LeMay, for one, recognized it.
* https://iro.uiowa.edu/esploro/outputs/undergraduate/If-We-Ha...
There is a paradox called “logical insanity.” The novel Catch 22 deals with this irony: basically, the idea was that the war was killing thousands daily, so in order to end it as fast as possible, they planned to be as brutal as possible. But what were alternatives?
Drop the bomb somewhere 'harmless': how would that convince the War Cabinet of anything? The point of all weapons is to harm to convince the enemy to stop and re-evaluate their costs.
Blockade and starve the Japanese out? Possibly millions dead. Invasion? The Japanese leadership thought that up to 20M of their own people would perish trying to repel the US landings.
And that's just the Japanese numbers: what about all the peoples that were still living under Japanese rule in Manchuria, Korea, etc?
And what about the American lives, which were Truman et al's first responsibility?
https://www.dancarlin.com/product/hardcore-history-42-blitz-...
The conduct of the allies in WW2 was atrocious.