While filming None But the Brave (1965), Brad Dexter had apparently rescued Frank Sinatra when he got into difficulty swimming. As a thank you, Sinatra agreed to star in this when Dexter was starting out as a producer.
The gun prop used in this film was later converted to become Han Solo's blaster in Star Wars: Episode IV - A New Hope (1977).
Filmed on location in war-torn Leipzig.
Final film of Nadia Gray .