WWII was set in a different "world" than what we have now...
Bear in mind that until modern times, actually fairly recently, torturing, murdering, enslaving, and being cruel to POW's was a pretty universal and accepted practice going back several thousand years. This is one of the reasons for the Geneva Convention and it's application for treatment of prisoners of war. Before you get too far down on other countries abuse of prisoners, look into the American civil war and how some of our prisoners (our own peoples) were treated. It wasn't all roses. We, America, have improved over the past century, some countries are still catching up.
Jack