This review may contain spoilers. I can handle the truth.
Christopher Bird’s review published on Letterboxd :
This review may contain spoilers.
A lot of people describe this as a "tense thriller" and... I don't really think it is? It's tense, but it's not a gripping thriller; it's tense because it knows exactly where it's going, which is towards inexorable disaster, and it doesn't steer away from that out of sympathy to the characters.
The basic idea of a hardened Navy martinet starting (one assumes) World War III out of an Ahab-esque obsession with pursuing the enemy isn't a cheerful one, and often the film seems dour as a result, but that dourness is what gives the movie its tension. You keep waiting for common sense to prevail, as character after character in the film tries to get Richard Widmark's captain to just let the Russian sub escape because what's the goddamn point anyway - that's your sense of story saying "come on, where's the character arc and when does it start bending," but in real life people don't have character arcs and sometimes people just fuck things up tremendously, and that's the movie that you get here.
A major problem with the movie is that Sidney Poitier's character is more or less extraneous for most of the film, and I consider this a flaw of adaptation; in the book (where the ending is somewhat different), his character is the sole survivor, and thus becomes relevant by default. In the movie, though, he dies with everybody else, and thus he's just a doesn't-know-shit journalist who gets to be Sidney Poitier Speechifying at the end, and that's disappointing if you like Sidney Poitier (which I very much do).
Still: in the present day when we're all suddenly worried about an idiot starting a nuclear war again, it's a sadly relevant film.