Operation Atlantis
Agente S 03: Operazione Atlantide (original)
An American agent discovers that the Red Chinese have built a secret atomic city from which they will attempt to invade America.
Starring John Ericson, Bernardina Sarrocco, María Granada, Carlo Hintermann, Beni Deus, José Manuel Martín, Erika Blanc, Dario Michaelis, Franco Ressel, Tullio Altamura
Watch "Operation Atlantis" from streaming services Amazon Prime, Paramount+, Paramount+ (Prime) and several more released in 1965. It's a crime and action & adventure movie, and has a rating of 4.4 out of 10 from Imdb which is fairly low for this kind of movie.
Watch it here
Amazon Prime