Simple; why not nuke them then? No rules; no fouls. The rules of war are an attempt at humans to create civilisation a step at a time. Stalin didn't believe in them; neither did Salvador Allende and he loved torture as a political device. Thats what you get without any rules. I think the rules; seriously, came about because people are scared shitless of the alternative because they know what people are capable of. People are not fundamentally good.