Platoon (1986)

Chris Taylor is a young, naive American who gives up college and volunteers for combat in Vietnam. Upon arrival, he quickly discovers that his presence is quite nonessential, and is considered insignificant to the other soldiers, as he has not fought for as long as the rest of them and felt the effects of combat. Chris has two non-commissioned officers, the ill-tempered and indestructible Staff Sergeant Robert Barnes and the more pleasant and cooperative Sergeant Elias Grodin. A line is drawn between the two NCOs and a number of men in the platoon when an illegal killing occurs during a village raid. As the war continues, Chris himself draws towards psychological meltdown. And as he struggles for survival, he soon realizes he is fighting two battles, the conflict with the enemy and the conflict between the men within his platoon.