I'm torn between The Battle of Algiers and Come and See...
& would also like to mention The Burmese Harp, The Red and the White, Rome Open City, Paisa, Stalingrad, Das Boot, The Deer Hunter, All Quiet on the Western Front (the original), The Big Red One, Patton, Paths of Glory, The Thin Red Line (Malick), A Bridge Too Far, Schindler's List, Salvador, Salo or the 120 Days of Sodom, Ran, Ashes and Diamonds, Closely Observed Trains, Alexander Nevsky, The Life and Death of Colonel Blimp, From Here to Eternity, Ice Cold in Alex, The Tin Drum, Europa Europa, Casualties of War, Three Kings, M*A*S*H....there are a lot of great war films!!
"See you on doomsday!"- Sadegh Hedayat's suicide note