This is a good cold war spy thriller that had all the elements to make it a great one, but it fell short. The culprit was the screen play's habit of inserting "magical" moments when characters emerge suddenly to change the scene without explanation. Because it's a spy film we are supposed to accept and believe that these moments occur because the forces at work are brilliant and well prepared etc., but it happened too often. Otherwise the film is very good indeed, with great on-location shots, excellent cinematography, a fine score, and a uniformly excellent, believable cast. Senta Berger lights up the screen in her US film debut, but her character's arrival, disappearance, then arrival and disappearance again are examples of those magical moments. Kudos to @krocheav who wrote a great review and brought out many of the strong and interesting points of the production, especially the "firsts" for John Williams, Richard Widmark, Jean Hazlewood, Senta Berger, Sonja Zieman and Alistair Maclean. [NB, I saw the film before I read that review.]