Tell me, in the 1800's, when the British fought the Indians, or the Americans fought the Native Americans, did they go by those "rules" for warfare? Nope. Same goes for today. There haven't been many conventional wars between major western powers lately, so we can't judge accurately, but I'd say the UN, the international laws, and the sanctions against powers who commit human rights abuses are pretty similar. The United States is at war with terrorists in Afghanistan, and France is at war with terrorists is Mali. It's the same kind of war that happened in the 1800's when the British fought Indian rebels.