The Death March - What Is It?

Of 78 to 80 thousand people who surrendered at batan, only about 54 thousand made it to the final destination. These people mostly had to do that treck on foot. The accounts were about individual japanese soldiers that were just sedistic or tortuous. We have an idea that troops should behave in a sort of a chivalrous fashion towards enemy troops that they capture. But that not the norm throughout history, is it?