Hondo (1953)

Army scout Hondo Lane (John Wayne) stumbles across an isolated homestead in the middle of Apache territory. The inhabitants, a woman and her son believe they are safe, as there is a treaty with the Apaches. Lane knows better though, as the Army has just broken the treaty, causing the Apache to seek revenge on settlers. Despite being a scout for the US Army, Lane has sympathies for the Apaches, having been married to a Native American woman and living with her people for five years. With divided loyalties he now must tread a fine line.

IMDb: https://www.imdb.com/title/tt0045883