Could it be The Longesty 100 Miles. See The Longest Hundred Miles (1967) (TV)
I have been searching my memory, the Net, friends' recollections, forums ... I think Robert Mitchum was the star - a war film - Vietnam? He is separated from his unit and a local family "donate" their daughter to him. At the end of the film the mixed race teenage daughter of this reunion (parents killed sheltering her tiny body) is welcomed to America by a group of his friends.
Could it be The Longesty 100 Miles. See The Longest Hundred Miles (1967) (TV)
Mitchum is behind enemy lines with a Korean family in The Hunters.
I'd say CHINA DOLL with Victor Mature. The ending is exactly as you describe, and Mature is given a young wife by her father. There's no behind enemy lines element, but the action plays out in wartime.