Retired CIA analyst Jack Ryan (Ford) is on vacation with his family in London. They witness a terrorist attack on Lord William Holmes (Fox), British Secretary of State for Northern Ireland. Ryan intervenes and is injured, but he kills one of the assailants, Patrick Miller, while his older brother Sean (Bean) looks on. The remaining attackers flee, as Sean is apprehended by the police. While recovering, Ryan is called to testify in court against Miller, who is part of a splinter cell of the Provisional Irish Republican Army. Miller is later convicted for his crimes.
In 1972, eight-year-old Francis "Frankie" McGuire sees his father gunned down due to his Irish republican sympathies. In September 1992, the grown-up Frankie (Brad Pitt) and three other I.R.A. gunmen are involved in a shootout in Belfast when Special Air Service commandos attempt to capture him. 18 British military personnel are killed or wounded. One gunman is killed and another, Desmond, is wounded as Frankie and the last gunman, Sean Phelan (Paul Ronan), escape. An SAS agent asks the wounded man where Frankie is. Desmond is fatally shot by the agent after he says "up your arse". Hiding in the countryside, Frankie and his friend Martin MacDuf (David O'Hara) see a British Army helicopter circling overhead and decide they need Stinger missiles.
Gerry Conlon (Daniel Day-Lewis) is shown in Belfast stripping lead from roofs of houses when security forces home in on the district with armoured cars, and a riot breaks out. Gerry's father, Giuseppe Conlon (Pete Postlethwaite), later saves him from IRA punishment, and he is sent off to London to stay with his aunt, for his own good. Instead, he finds a squat, to explore, as he puts it, "free love and dope". One evening by chance he gains entry to a prostitute's flat and he steals the £700 he finds stashed inside; on that evening in Guildford there is an explosion at a pub that kills four off-duty soldiers and a civilian, and wounds sixty-five others.
County Cork, Ireland, 1920. Dr. Damien O'Donovan is about to leave his native village to practise medicine in a London hospital. Meanwhile, his brother Teddy commands the local flying column of the Irish Republican Army. After a hurling match, Damien witnesses the summary execution of his friend, Micheál Ó Súilleabháin, by British Black and Tans. Although shaken, Damien rebuffs his friends' entreaties to stay in Ireland and join the IRA, saying that the war is unwinnable. As he is leaving town, Damien witnesses the British Army vainly trying to intimidate a railway guard and the train driver for refusing to permit the troops to board. In response, Damien decides to stay and is sworn into Teddy's IRA brigade.
Former Irish pugilist & Provisional IRA member Danny Flynn (Daniel Day-Lewis) returns home to Belfast from a 14-year stint in prison at the age of 32. Weary of the unbroken cycle of violence in Northern Ireland, he attempts to settle down and live in peace. After meeting his drink-sodden old trainer Ike (Ken Stott), Danny starts up a non-sectarian boxing club for boys in an old gymnasium. While fixing up the old building, however, he runs across a cache of Semtex hidden underneath the stage. He throws the cache into the river.
The film is divided in over 30 chapters. In the fictional Irish town of Tyrellin, near the border of Northern Ireland in the late 1940s, cartoon robins narrate as Patrick Braden's mother, Eily Bergin, abandons him on the doorstep of the local parochial house where his father, Father Liam, lives. He is then placed with an unloving foster mother. Biologically male, a young Patrick is later shown donning a dress and lipstick, which angers his foster family. Patrick is accepted by his close friends Charlie, Irwin, and Lawrence, as well as by Lawrence's father, who tells Patrick Eily looked like blonde American movie star Mitzi Gaynor.
Gary Hook, a new recruit to the British Army, takes leave of his much younger brother Darren. Hook's squad of British soldiers is sent to Belfast in 1971 in the early years of The Troubles. Under the leadership of the inexperienced Lieutenant Armitage, his squad goes to a volatile area of Belfast where Catholic Nationalists and Protestant Loyalists live side by side. The unit provides support for the Royal Ulster Constabulary as it inspects homes for firearms, shocking Hook with their rough treatment of women and children. The Catholic neighbourhood has been alerted to the activity and a crowd gathers to protest and provoke the British troops who, though heavily armed, can only respond by trying to hold the crowd back.
The film begins with a small IRA team, including Martin Fallon (Mickey Rourke) and Liam Docherty (Liam Neeson), watching as two British Army Land Rovers approach the roadside bomb they have set for them. At the last minute, a school bus overtakes the army vehicles and detonates the bomb as it passes, killing the children. After most of the team escape the scene pursued by the soldiers, Fallon travels to London in a bid to escape the past. In London, he is approached by a contact who asks him to take on one last job on behalf of local gangster Jack Meehan (Alan Bates) and his brother Billy Meehan (Christopher Fulford). They offer Fallon money, a passport and passage to the US if he kills a rival gangster. Initially reluctant, he nonetheless takes on the job. However, as he is carrying out the hit in a graveyard, he is seen and confronted by the local Catholic priest, Father Michael Da Costa (Bob Hoskins). The confrontation is watched from a distance by Billy Meehan, who tells his brother there is a witness to the killing.
The film unfolds with an Orange walk on The Twelfth, and a tape being handed to an American human rights activist, which becomes his death warrant. It begins with a quote from Margaret Thatcher insisting that Northern Ireland is part of Britain. It ends with one from a former British intelligence agent, stating, "There are two laws running this country: one for the security forces and the other for the rest of us."
Ivan Cooper organise une marche pacifique pour l'égalité des droits entre catholiques et protestants, en Irlande du Nord. Mais la manifestation dégénère et des manifestants sont abattus par des soldats de l'armée britannique. Cette fusillade sanglante a fait 13 morts et 14 blessés par balles. Une 14e victime mourra quelques mois plus tard succombant à ses blessures.
In Lurgan, Northern Ireland, during 1975 and the Northern Irish Troubles, the Irish Republican Army are targeting British loyalists and the loyalist Ulster Volunteer Force are exacting revenge on Catholics they claim are militant republicans. Alistair Little, 17, is the leader of a UVF cell, eager to let blood. He and his gang are given the go-ahead to kill a young Catholic man, James Griffin, as a reprisal and a warning to others. When they kill Griffin, his 8-year old little brother Joe Griffin watches in horror. Little is arrested and sentenced to prison for 12 years.
Colm (Barry McEvoy) takes a job as a barber in a Belfast psychiatric hospital. He meets the staff and is warned against talking about poetry with George, a fellow barber (Brían F. O'Byrne). when he brings it up, George subjects him to his own poor work. The pair chat anyway. Later they meet an orderly escorting a new patient, whom he refers to as "The Scalper" (Billy Connolly), described as the only seller of hair pieces in all of Northern Ireland until he had a nervous breakdown and scalped some of his own customers. Colm and George decide to meet with the Scalper to gain his list of customers; they intend to take over his former hairpiece monopoly. The Scalper agrees to give them the list.