For me the the last line in the movie Platoon as the wounded Chris is air vac out of the hell of Vietnam said it all. He is looking down at the carnage and death below him he thinks....
"I think now, looking back, we did not fight the enemy, we fought ourselves, and the enemy was in us. The war is over for me now, but it will always be there, the rest of my days. But be that as it may, those who did make it have an obligation to build again. To teach to others what we know, and to try with whats left of our lives to find a goodness and a meaning to this life."
Chris Taylor