Trauma in Movies

I watched "The Deer Hunter" this weekend, and I found it to be a good movie, very interesting. I find that there are some parts that are very hard to understand in it. I'm still trying to figure out why Christopher Walken's character had kept playing Russian Roulette. He knew that one of his friends were alive, as he as sending him money from Vietnam. I have wondered if it was Christopher Walken's attempt to relive the traumatic expierence in the Vietcong prison, where he was forced to play it with Robert DeNiro. I thought that it could relate to, I believe it was in Caruth's book, how the mind would try to relive the expierence of traumatic event, because it wasn't consciouss of it at the time. That the mind would strive to relive it, as if to relive it so it could die, which I thought that this might be what Christopher Walken was going through, since he obviously did not care whether he died or not, almost as if he was hoping to get killed in the game.
I'm still not sure about what had happened. I couldn't figure out why Robert DeNiro's character was at the Russian Roulette game when Christopher Walken had first stumbled upon it. I thought at first that maybe they were there to help, I thought this had to be it as Christopher Walker grabbed the gun, but then he put it against the guy's head and pulled the trigger, then pointed it towards his own. Could the game of almost been a connection between Christopher Walken and Robert DeNiro, as they both thought each other was dead. It couldn't be something as simple as Christopher Walken showing he was not afraid, even though I think it seemed like how he pulled the trigger at his own head showed part of that. Was there some kind of perverse feeling that, since they had been the ones being forced to play the games earlier, they got from watching since it was now them on the outside getting to watch two other guys go through it. It might be that they were not fully conscious to the event that had happened in the Vietcong prison, and they were trying to relive it. I've seen in other films how the victims of rapes and other attacks, change and seem to almost become the monster that had first attacked them. It is like a kid who has been picked on during highschool, but once he grows taller and stronger, he has the urge to pick on kids. It could be that the victims of these events, that by changing who they are, they can change their past. I'm not sure as towhat happened, but I 'll keep thinking about it, and do some research and see if I can find why they reacted like that.