This might be hard to believe, but John Rambo was originally a symbol of the horrors of war. Really, he was. Whatever he morphed into, he began his life as a... a cautionary tale. Can you create a perfect soldier, ready him to handle whatever he would come across in the middle of  a war, and then just expect him to shut it off and go back to a normal life? There were some heavy questions at play in "First Blood." Not that we address any of them in any meaningful way, but they are there.