Project X

Overview
Project X was one of a cycle of anti-Red films produced in the late 1940s. Keith Andes plays an ex-Communist who is strongarmed into cooperating with the Feds. Pretending to become a "comrade" again, Andes rejoins the local Communist cell. Moving about freely, he is able to track down a gang of spies who are smuggling atomic secrets. Filmed on location in New York, Project X has the surface "feel" of a documentary, though the dialogue is strictly from the funny papers. Keep an eye out for a very young Jack Lord.
Similar
The Manchurian Candidate (1962)
The Ambush (1969)
Tail Gunner Joe (1977)
The Red Horse (1981)
Superfluous (1962)
Dongmei (1960)
The Way We Were (1973)
Balkan Rules (1997)
Dreams, Life, Death of Filip Filipović (1980)
The Funeral (1996)
100 Days Before the Command (1991)
Indochine (1992)
Good Night, and Good Luck. (2005)
The Lost Honor of Katharina Blum (1975)
A Thousand Years of Good Prayers (2007)
Newton (2017)
The Spy Who Came In from the Cold (1965)
The Photograph (1987)
The Woman on Pier 13 (1950)
Accident (1977)