John Winger, an indolent sad sack impulsively joins the U.S. Army after losing his job, his car, his girlfriend and his apartment … and, for good measure, he cajoles his best friend into enlisting, too. After making it through boot camp, the duo appropriates a state-of-the-art military vehicle for a weekend furlough, landing behind the Iron Curtain -- and in the midst of an international incident.