In the late 1980s, Anthony Swofford (Jake Gyllenhaal) enlists as a Marine, training in boot camp under a sadistic drill instructor. Swofford undertakes a sniper course headed by Staff Sgt. Sykes (Jamie Foxx) during this time, which is shortly before the advent of the Gulf War. When the United States becomes involved, Swofford is shipped out, along with his spotter, Alan Troy (Peter Sarsgaard). Facing uncertainty each day — about the war and home — the soldiers try to maintain composure.