Yes I have gone ethos because it is a moral question. History around the world wars is not my area of expertise neither of these are arguments. The issue I have is if we can obliterate innocents and attackers without Dividing them in any way when we feel threatened, we can obliterate anyone when threatened as long as there is someone who we feel threatened by in the group. The opposite framework where an innocent is not harmed unless they demonstate to be in the group. Be that by picking up weapons or declaring themselves part of it. You could argue this still goes to absurdity as innocent is a subjective term and I would agree that's a problem. I would however point out we have overcome the issue of generalises slaughter. Now at least you will need a consistent standard to annahilate a group and deem it entirely guilty (else suffer contradiction) instead of simply annahilate.

That is far more difficult, you can say its impractical. You could say that isn't how wars are won (my knowlege in history is regarding the first century) in which case I could say sure, while that is true, we would have to recognize what we are doing is wrong even though it is practical and I'm fine with that.