Jack Ryan (BEN AFFLECK) is a 28-year-old CIA analyst whose 14-month stint with the agency would be unremarkable if not for his expertise on Alexander Nemerov (CIARAN HINDS), who's now in control of Russia due to the former president unexpectedly dying.
Unable to tell his girlfriend, Cathy Muller (BRIDGET MOYNAHAN), of his real job, Jack suddenly finds himself at the side of CIA director Bill Cabot (MORGAN FREEMAN) and traveling to meet Nemerov and his ex-KGB advisor, Anatoli Grushkov (MICHAEL BYRNE), who don't think unrest in Russia is of any concern to the U.S.
After visiting a nuclear research facility and noting that three of the scientists are missing, however, the agents' suspicions are aroused. Accordingly, Cabot gets in touch with government operative John Clark (LIEV SCHREIBER) to find out what happened to them and what they might be up to.
Little do they know that they're working for Richard Dressler (ALAN BATES) a wealthy European industrialist and neo-Fascist leader who's acquired a long missing nuclear warhead from South African arms dealer Olson (COLM FEORE). Convinced that he can sway people over to his ideology after anonymously starting WWIII by pitting the U.S. and Russia against each other, Dressler sets his plan into motion.
As the various agents continue to do their work, catalytic global events begin to occur that lead the superpowers ever close to all out nuclear strikes on each other. With U.S. President Fowler (JAMES CROMWELL) trying to figure out what to do, and working with the advice of Defense Secretary Becker (PHILIP BAKER HALL), Secretary of State Owens (RON RIFKIN) and National Security Advisor Revel (BRUCE McGILL), Jack races to find out the truth and prevent nuclear Armageddon from occurring.