“What it takes is the resolve and will to use a level of brutality and violence that your generations can’t stomach. And until you can, this s*** won’t stop.
It took us on the beaches with bullets, clearing out caves with flame throwers, and men like LeMay burning down their cities, killing people by the tens of thousands. And then it took two atom bombs on top of it! Plus, we had to bomb the s*** out of German cities to get them to quit fighting. But, if that was what it took to win, we were willing to do it.”
Put more succinctly, the war doesn’t really end until the enemy KNOWS he is defeated. That takes inflicting so much pain and damage that they beg to surrender just to make it stop. Such damage is not inflicted with smart bombs and avoidance of civilian casualties.
To paraphrase Gen Curtis LeMay: “If you kill enough of them the enemy will surrender.”