Zombies of the Stratosphere (1952) (1952)

MacDonald Dean Jagger portrays Armand Louque, an officer in the French Army of World War I, who has stumbled upon an ancient tale of soldiers turned into automatons, or "zombies", who are impervious in battle and may hold the key to victory in the war. At first he has trouble convincing his superiors of this phenomenon, but eventually French General Duval orders a non-military expedition into the ancient Cambodian city of Angkor to find the secret of the zombies and destroy it.