Personally, I think that having those expectations can actually be harmful.
If you (general you) expect war to have some standards of decency, I think you are less likely to fully oppose it, because you expect it not to be that bad. But if you realize that horrific atrocities are unavoidable in war, that it has no standards of decency, then I think you are going to try to avoid it much harder, to look for peaceful alternatives with much greater urgency.