Nobi (Fires on the Plain), an underseen Kon Ichikawa classic that truely shows the horros of war. No glorification here. It got released in America through Criterion. You could also check out the war movies by the Polish filmmaker Andrzej Wajda. Another interesting movie (although post-war) is Germany anno zero, by Rosselini. And while you're at it check out Rome, Open city as well. Something more recent is Malick's The Thin Red Line or Ben Stiller's Tropic Thunder. If you're interested in a good holocaust documentary check out Shoah (it's almost 10 hours long, so take a few days for it). [edit] I forgot to mention Sam Fuller's The Steel Helmet and the The Big Red One and Peckinpah's Cross of Iron.