More tidbits from Stars in Blue: Movie Actors in America's Sea Service
In 1940 his reported income was over two hundred thousand dollars. That same year, Bob volunteered for duty in the American Field Service, becoming one of the first Hollywood stars of World War II era to enlist in the armed forces. He drove an ambulance in France until the Americans were forced out after Dunkirk fell. The actor escaped the onrushing German jugernaut through Spain and Portugal, but his withdrawal was temporarily delayed by a side trip to fly to the rescue of fellow thespian Madeleine Carroll, trapped on the Riviera.
In early 1941, Bob applied for US Naval service. While he waited for the response he made several movies in quick succession, no doubt anticipating the lost income that acceptance into the military would mean. He and his wife also scaled down their lifestyle, dismissing servants and selling their estate and fancy cars. Lt. (jg) Henry Robert Montgomery was commissioned in the U.S. Naval Reserve on 28 April 1941. After a one-month assignment with the Office of the Chief of Naval Operations in Washington, he reported as assistant naval attache at the U.S. Embassy in London. His duties as an intelligence officer there included running the Naval Operations Room, which tracked the location of all British ships.