Anyway
Many people feel regret over various aspects of World War II, including veterans who only killed enemy soldiers in what was honorable combat against a violent and viscous enemy who attacked them. No reason to think military commanders wouldn’t also express regret over using destructive weapons, even if they would have made the same decision over again. There’s no moral difference between bombing a city and killing civilians and bombing a factory making ordinance and also killing citizens. You seem to lack a fundamental understanding of the nature of warfare, and in particular Total War. There are no innocents. Unsurprisingly, the West were the only powers that gave even the slightest damn about minimizing civilian casualties. Which is why we are sitting here talking about western actions because we are a moral people by and large. Nobody in the former USSR has any regrets over raping and murdering Germans.
Same commanders ordered many gruesome, albeit necessary military decisions that resulted in the deaths of soldiers, women, and children.
Interestingly you aren’t quoting those who express regret over any number of those other decisions. Why is that?
Find us some quotes of Japanese commanders that survived the war and their regret over their heinous and disgusting acts. If not maybe you can find some Chinese friends or Filipino colleagues (or others) who can enlighten you.
Truman did not regret using the bombs and would have done it again, and as he said “at the snap of my fingers”, despite being sorrowful for the death and destruction caused. His opinion matters more than anyone else’s since it was his decision. And, your random quoting of people like “nuke them all “ Curtis LeMay shows you don’t even know anything about who you are quoting.
QED.