Hell to Eternity (1960)

American Marine hero convinces enemies to surrender through Japanese skills 

Based on the true story of Guy Gabaldon, a Hispanic man raised in 1930s Depression-era Los Angeles by a Japanese-speaking foster family. After the attack on Pearl Harbor, he enlisted in the Marines, where his language skills proved invaluable. During the South Pacific campaign and the Battle of Saipan, his knowledge of Japanese helped turn him into a war hero when he convinced 1,000 Japanese soldiers and 500 civilians to surrender.