At the time this film was released, in 1940, World War II had already begun in Europe, but the Soviet Union still had a non-aggression pact with Nazi Germany. In the film, Mac is able to fool a character by pretending to hear news that Germany has broken the pact and launched an invasion of the USSR. Of course, that's exactly what happened the very next year when Germany launched Operation Barbarossa in summer 1941.
Paul Morrissey (director of many Andy Warhol films) once acknowledged that Comrade X was his favorite movie.
The fleeing of the inept Romanian army in the wake of the single Soviet tank commandeered by Mac (Clark Gable) presaged the Soviet army's smashing of the Romanian Third Army in Operation Uranus in November 1942, leading to the first major Soviet victory of the war, the Battle of Stalingrad.
At the marriage license bureau, Theodore tells Mac that she had been married twice earlier. At the time the film was released in December 1940, Hedy Lamarr had been divorced from her second husband, Gene Markey, for about two months.
This film received its initial television broadcasts in Seattle WA Monday 12 Novembewr 1956 on KING (Channel 5 and Saturday 17 November 1957 on WFIL (Channel 6), followed by, and by New York City NY Friday 4 January 1957 on WCBS (Channel 2); in Chicago IL it first aired 4 March 1957 on WBBM (Channel 2), in Altoona PA 17 April 1957 on WFBG (Channel 10), in Minneapolis MN 14 August 1957 on KMGM (Channel 9), in San Francisco CA 2 January 1958 on KGO (Channel 7), and in Los Angeles CA 21 February 1958 on KTTV (Channel 11).