Halls of Montezuma (1950), directed by Lewis Milestone.
While invading a Japanese-held island, a Marine patrol must capture some prisoners to find out where the damn rockets are coming from. It's a race against the clock to knock them out before the general invasion starts. The Lt (Richard Widmark) is tired, having migraines, and he fears that none of his men are going to survive the war.
After a slow start with several pre-war flashbacks, it's pretty exciting, although brutal with almost continuous bombardment. We get details of the landing craft, making a beach-head, and bringing up the tanks to spray napalm on entrenched positions (some real footage).
Tough guys to spare: Richard Boone, Jack Palance, Karl Malden (dies), Neville Brand (blinded), Jack Webb, Bert Freed. Plus Robert Wagner (dies) and Skip Homier (goes nuts and dies). Philip Ahn is the chief prisoner (survives). Although he gets to be the typically inscrutable, insidious Oriental, the other Japanese are a mixed lot of ordinary guys.
It's a story of considerable suffering; the brassy Marine's Hymn at the beginning and end is jarring, as is the little patriotic recitation. The Lord's Prayer is easier to take. The sound-track choir sings the older "admiration of the nation" version of the Hymn.
Widmark's call sign is "pansy baker".