Actor Steven Geray mispronounces the capital of Turkey as ANN-KAHRA.
Rudick is referred to as being 52 years old my Col. Robinson. Actor Frank Reicher looks every year his real age - 68.
Sydney Greenstreet filmed a special trailer where he talks directly to the camera.
The three photographs of possible Roumanian secret agents which McNamara shows Joe were those of the Warner Bros. contract players 'Paul Panzer', Glen Cavender and Stuart Holmes. Those three are not actually in the movie. The fourth photograph was that of Leo White who is seen in an early scene whispering in someone's ear.
This film is mentioned in Jack Kerouac's "On the Road" as the second in a double feature seen by Sal and Dean in a Detroit theater (chapter 11 of part three).