The Sergeant and the Spy (1954)

A trip to Paris has been long in the making for Sergeant Stanley Gilchrist and his army buddy Hank, who are stationed in Milan. But when Stanley requests a furlough from his tyrannical colonel, he's assigned to London instead to deliver a top-secret document. Undaunted, Stanley and Hank sneak in a brief stay in the City of Lights. Their holiday turns into a nightmare when the bag containing the secret documents disappears.