Alan Ladd plays the title role in Captain Carey USA. A former OSS operative, Captain Carey returns to Italy after the war to avenge the death of resistance worker Giulia (Wanda Hendrix). Much to his surprise, Carey finds that his "deceased" lover is not only still alive, but also the wife of a powerful Italian nobleman (Francis Lederer). He also discovers to his sorrow that the far-from-grateful Italian villagers hold the Americans responsible for their current financial travails. Still, Carey sticks around, hoping to flush out the traitor who'd caused the wartime deaths of several of his OSS colleagues. The box-office success of Captain Carey USA was enhanced by the incidental musical number "Mona Lisa," which subsequently won an Academy Award.
~ Hal Erickson, All Movie Guide