Being the 'Good guy' has its costs
Deal with the restrictions or give up on trying to claim the moral highground.
The fact that we have been kind to our prisoners of war has, in the end saved american lives. Japanese military and civilians were indoctrinated that we torture and kill prisoners so they fought to the death... That lie was harder to sell more recently, and in the first gulf war we were overwhelmed with surrendering troops.
Being humane is in our best interests, it saves lives on our side and theirs.