Ava Gardner and the title evoke The Night of the Iguana from 1963. Unfortunately she had little to work with as a lush love interest for Gregory Peck's nuclear submarine captain. (His Oscaring for To Kill a Mockingbird was also in 1963.) Fred Astaire played a suicidal scientist/engineer. A not-yet-Psycho Anthony Perkins and young wife Donna Anderson (hysterical as demanded by the times) rounded out the main cast. Amongst various maulings of Waltzing Matilda we obliquely learn that a nuclear exchange in 1964 has exterminated humanity in the northern hemisphere, leading this Hollywood cabal to set up shop in a back-to-the-future Melbourne (Point Lonsdale, Frankston, horses and carts, bicycles, far from the fallout) where alcohol, boat races, romance and endless cigarettes are all that's on offer in the end times.
Aboard the sub on a tour of the sterile Pacific, Astaire mouths off at vacuum tubes and transistors (not so far from Kaczynski), reflecting the fear and not the reality of the missile gap propaganda of the day. Soon enough that was supplanted by the Mutually Assured Destruction of the far superior Dr. Strangelove. I wonder if all the arse slapping is in Nevil Shute's novel.
Somewhat topical with the current Russian assault on the Ukraine. Bosley Crowther at the time. Trivia at IMDB.