Most remarkably, the film Jack Warner would call the only one he ever regretted making — after a grilling before the House Un-American Activities Committee that sent Koch into blacklisted exile — was personally commissioned by the President of the United States, who asked Warner Bros. to make it as part of Hollywood’s efforts to whip Americans into a patriotic frenzy during World War II.

“President Roosevelt himself asked Harry and Jack Warner to assist in educating, entertaining and enlightening the American people,” says Harry’s granddaughter, film historian Cass Warner. “Little was known about the Soviet Union, who were our allies at the time, [but] this never came to the forefront even when the film was used as evidence of the Bros. making subversive films during the McCarthy Era.”

Americans in late 1942 still deeply distrusted the Soviets, who had joined World War II on the Allied side after earlier entering into a non-aggression pact with Hitler. Hollywood’s depiction of the USSR up to that point was mostly unsympathetic; Greta Garbo, playing a commissar in “Ninotchka” (1939), quipped there would be “fewer but better Russians” following Stalin’s notorious purge trials.

With the administration’s encouragement, Hollywood quickly began praising Russian soldiers and brave peasants facing down the Nazis in films like “The North Star,” written by Lillian Hellman, and the musical “Song of Russia.”

But the Warners took this wartime love-fest to delirious heights of insanity with the lavish “Mission to Moscow,” which incredibly arrived in theaters just four months after Koch was summoned by the Warners. Koch very loosely based his script on the memoirs of Joseph E. Davies, an FDR pal who had served as the US ambassador to the USSR in the late 1930s.