I forgot to add this: In WWII the Brits burned German Cities to the ground with their night raids. Some of it was strategic but most was for terror. The destroyed dams and unleashed floods on Germany and much death. Some of it was strategic but most was for terror. It worked! The Brits were somewhat irritatted with the bombing of London and her other great cities. We smoked Nagasaki and Hiroshima with nukes. Some of it was strategic but most was for terror. It worked!
War is ugly dirty business to be avoided if possible. “Jaw Jaw Jaw is better than war war war.” Winston Churchill. If it can not be avoided, go Genghis Khan on the enemy. It works. Churchill and the Allies went Genghis Khan on our enemies, it works.
The best war is the one that does not happen because your enemy fears you.
As I like to say, there is absolutely nothing to be sorry about regarding Hiroshima and Nagasaki. Besides the many American deaths and injuries avoided, we literally saved millions of Japanese lives, and millions of Chinese and other occupied territories lives (Korean in particular) as well, by dropping those bombs and forcing surrender, vs. invading Japan.
Anyone who thinks otherwise is completely ignorant about the history of the era, and needs to sit down and shut up until they fix their ignorance and can discuss the issue from a position of knowledge.