Nobody deserves to die of radiation poisoning. There is no neighborhood on Earth in which all families living there deserve to be vaporized.

Hiroshima and Nagasaki weren't even the most destructive bombings. Firebombing of Tokyo in 1945 killed 100K people in a single night.

I appreciate this point. That's a really valuable reminder. I think I was so caught up in the horror of radiation poisoning that I overlooked it.

I’d caution against using the word ‘deserve’ so loosely. While you may see it as meaning ‘imperial Japan had to be stopped by any means necessary’, it comes off more like retribution. It comes off like a bloodlust for revenge.

In general, ‘deserve’ should always be followed with ‘because…’. Just saying x deserves y assumes we agree on: what x did, an ethical/moral system, and that y is the best punishment/reward in that ethical/moral system.