Carolyn Jones was originally cast as "Sharon Kensington" but switched roles with Shirley MacLaine in order to play Shirley Drake because she wanted the less flamboyant role.
Dean Martin still had four pictures left in his old contract with producer Hal B. Wallis with whom he hadn't worked after his break-up with Jerry Lewis. Wallis refused to raise Martin's salary, but the star was interested in playing a more serious part and accepted the role of Maury in this picture. After this film, Martin made three more pictures with Wallis: All in a Night's Work (1961), The Sons of Katie Elder (1965) and 5 Card Stud (1968).
The film-within-a-film is titled "War Devils".
Bette Davis was originally sought for the part of "Shirley Drake" and William Holden was considered for "Maurice Novak" (The Hollywood Reporter, 1958).
One of the earliest Hollywood films to mention (pejoratively) the blacklisting of the McCarthy era, although it is rather circumspect about this.