There is that possibility --and we saw that in WWii with German prisoners of war captured by Soviet forces. On the other side US forces were much kinder to German PoWs, but that's perhaps because it wasn't as personal a war to us.
Ethics and morality don't help win wars --but they are good PR post war, if you are the winner.
There is no clean answer to this problem because your enemy will by all means take advantage of your self-imposed constraints. Osama even admitted fighting the Soviets was very, very hard fought --and fighting the Americans would be a much easier task in his view. Here is one place I might agree with his assessment.
Ethics and morality don't help win wars --but they are good PR post war, if you are the winner.
There is no clean answer to this problem because your enemy will by all means take advantage of your self-imposed constraints. Osama even admitted fighting the Soviets was very, very hard fought --and fighting the Americans would be a much easier task in his view. Here is one place I might agree with his assessment.