In wars, each side tries to monsterfy or demonize the other, so the soldiers feel ok about killing them. Humans seem so much more willing to kill and enslave others, if they can tell themselves, the others are less then human, evil and or less then they are. Then you can take what of theirs what you want, kill them, enslave them, rape their women and so forth.

Star Trek used to have scenarios on this topic too, but Enemy Mine really puts it up front and center. The first clip is just a short one, but has a need message, the second clip shows more what the movie is about if you have never seen it.

http://www.youtube.com/watch?v=9k4kiz9UWY8


http://www.imdb.com/video/screenplay/vi2024079641/


Another good one is Little Big Man, the American Indian story of brutality and war, from the perspective of the Indians. These movies affect emotions and feelings on a long term basis, at least for me it did.