Halls of Montezuma (1951)

Lieutenant Carl Anderson (Richard Widmark) is a former teacher who leads a band of Marines to an island under Japanese control during World War II, intending to capture enemy soldiers and gain information. When a Japanese soldier reveals a cave where his forces are willing to surrender, the Marines arrive there, only to be ambushed and suffer grave casualties. Now Anderson, having lost much of his original team, must summon up enough courage to attack an important rocket base.