I recently got exposed to Samuel Fullers The Steel Helmet. Its a movie about the Korean War which is remarkable in itself; but it also examines such complex issues as racism, treatment of enemy POWs, and the affliction of Post Traumatic Stress Disorder (or Shell Shock as I prefer to call it). The movie is decades ahead of its time, these issues were not really examined until after Vietnam, and here is a black and white movie about the Korean War exploring the subjects.
It can be instant watched on netflix, highly recommended.