No, humanity goes long before law does my friend, because you can't be very "humane" while you're running around WOUNDING, MAIMING, AND KILLING other human beings, now can you?
Nope, I don't ever remember once them teaching us any "humane" ways of killing and maiming our enemies, only the most efficient and brutal ones. Whether it be by shooting them, or running a bayonet into their GUTS, and leaving them screaming on the ground to die from infection, or dropping bombs and napalm on 'em, the purpose of the United States military is now, and always has been, to KILL as many of our enemies, and break as much of their stuff, as quickly as possible, and in an orderly, efficient, proficient military manner.
Law? That's a bunch of crap, dreamed up by a bunch of lawyers, to guarantee that they can get their greedy hands into the pie, even thought they're too GUTLESS to actually pick up a weapon and join the REAL Soldiers. If you ever REALLY want to see an end to war, let the military make it as absolutely brutal and heinous as possible, that way NOBODY will want to 'play' that game, EVER!