The Wonderful Country (1959)

Marin Brady (Robert Mitchum) is an American gunfighter making a living in Mexico protecting two local Mexican big-wig brothers. He suffers a broken leg while escorting a wagon into the US and gets stuck there for a few months, during which time he falls in love with a local cavalryman's wife (Julie London). The theme of the film is really "running away": Brady has initial run away from the US following a (justified) killing and gone to live in Mexico, although he wants to stay in the US he is forced to flee again after killing another man, following his return to Mexico he then abandons he employers, and then finally leaves the farming family that had taken him in.

Mitchum is effective as an amiable enough character who is liked (and encouraged to stay) by pretty much everyone he meets, but doesn't entirely feel at home in his adopted country of Mexico (and is suspicious of how well he'll fit in in the US). London is less effective as the bored wife, mostly because we never really learn much about here marriage or her antipathy towards he husband.

I don't think The Wonderful Country is one of the absolute classics – it's just slightly too focussed on Robert Mitchum's character and doesn't have a lot beyond that. However, it's a very interesting character study—and well worth watching—exploring Brady's feelings about his home country, how that affects his feelings about Mexico where he'd previously been living happily, as well as his sense of loyalty towards his employers, the feuding Mexican brothers. There's a lot to enjoy here.