There will one day spring from the brain of science a machine or force so fearful in its potentialities, so absolutely terrifying, that even man, the fighter, who will dare torture and death in order to inflict torture and death, will be appalled, and so abandon war forever.
If you deny that any principles of conduct at all are common to and admitted by all men who try to behave reasonably - well, I don't see how you can have any ethics or any ethical background for law.