While on vacation in London with his wife and daughter, Naval Historian and Professor Jack Ryan is witness to a brutal IRA terrorist attack and assassination attempt on a popular and influential British politician, Lord Holmes. Risking his life, Ryan is able to disarm one of the terrorists and engages in a fierce gunfight, killing one of the terrorists and throwing them in confusion before being wounded. His actions at that critical moment, stalls the assault and allows the police to respond in time, foiling their plot and forcing them to flee. Afterwards, John Ryan is hailed a hero. But one of the terrorists that he has slain, Patrick Miller has a brother. And Sean is enraged and vows vengeance upon Ryan for killing his family.
Returning home, his wife and daughter are subsequently attacked by Sean Miller and elements of the IRA and Ryan himself is targeted for assassination. With his daughter hospitalized, Ryan must take the fight to the terrorists themselves and turns to his contacts in the CIA for aid.
To protect his family, Ryan must hunt these self-styled patriots down before they can kill again and unleash their murderous games upon their unsuspecting targets ... before its too late.
- Harrison Ford as Jack Ryan
- Anne Archer as Dr. Caroline Catherine "Cathy" Ryan
- Patrick Bergin as Kevin O'Donnell
- Sean Bean as Sean Miller
- Thora Birch as Sally Ryan
- James Fox as Lord William Holmes
- Ellen Geer as Rose
- Samuel L. Jackson as Lieutenant Commander Robby Jackson
- Polly Walker as Annette
- J.E. Freeman as Marty Cantor
- James Earl Jones as Vice Admiral Jim Greer
- Richard Harris as Paddy O'Neil
- Alex Norton as Dennis Cooley
- Hugh Fraser as Geoffrey Watkins
- Alun Armstrong as Sgt. Owens
- David Threlfall as Inspector Robert Highland
- Andrew Connolly as Charlie Dugan