In a word: boring. If you want another word: contrived.
Long ago, I indiscriminately put a lot of movies labelled "film noir" in my Blockbuster queue; when I transitioned to Netflix, I moved them over. Even though the Netflix algorithm advised I wouldn't like it much, I decided to chance bumping it up to the top. Bad decision!
I don't think it's noir, not even close. Made in 1949, it was meant to illuminate the illegal immigrant problem from Mexico, and how criminals on both sides of the border exploited cheap undocumented labor. U.S. and Mexican law enforcement decide to investigate, putting American cop Jack Bearnes (George Murphy) and Mexican cop Pablo Rodriguez (Ricardo Montalban) undercover to investigate the racket.
And they did a great job, which is why we don't have any of those problems, over sixty years later.
It's slow, right up until the end; it gets violent when the bad guys (led by Howard Da Silva) see through Bearnes's cover story and Rodriguez tries to rescue him.
The movie is very earnest, with a pretentious narration at the beginning and end prattling on about the great friendship and cooperation between the two great countries, blah, blah, blah. It's directed by Anthony Mann, but he's done better. Searching around IMDB will tell you about the great cinematography, but … eh.