Mr. DuLac’s review published on Letterboxd :
All wars are idiotic. I don't care who wins.
Marlon Brando's choice in roles is almost as interesting as his performances. Here again he checks his ego at the door as he plays a less then heroic German pacifist that is blackmailed by the Allies into helping them during World War II. In true Brando fashion he manages to make his character, Robert Crain, likeable through charisma alone.
Somehow this manages to be the only film that Brando did with Yul Brynner. They're not an obvious pairing, but they're fantastic playing off each other here. Brynner is a shamed Nazi Captain reduced to working on a freighter. He plays it full of rage and constant paranoia. It's the perfect contrast to Brando's calm calculated performance as the spy impersonating an SS Officer.
The movie ends up as an above average saboteur/spy thriller not just with the performances, but the story has Robert Crain constantly thinking on his feet while manipulating the crew to always suspect others of foul play and never himself. Besides it's Brando.