Just finished this movie today. Highly recommend it. I watched it when I was a kid I wasn't old enough to understand it.

Vietnam war hero comes back to the USA, only to get treated badly by the society that sent him to the front lines of war. He is not welcomed back into society and he starts to see strong similarities to the society at home here in the USA and the enemy he used to fight against in the Vietnam war. This puts him on the wrong side of the law and at that point all hell breaks loose.

https://www.youtube.com/watch?v=N9VSWPG3JGI&t=0m10s