I prefer a rational response over an absolute approach. Don't get involved unless we absolutely must.
Unfortunately, I think the only way to do that is to change the rules of engagement to be "destroy the enemy utterly". There is no kind face to be put on war and we need to stop letting anyone try to tell us there is. The result of war is death, suffering, and carnage. Whether all at once or drawn out over a long occupation. Make it all at once. Own the terribleness of it, so that we don't do it very often.