The Troubles (in Irish, Na Trioblóidí).

It seems too polite a term for the violent conflicts that raged for three decades in Northern Ireland.

Too polite and too simplistic. As the new war drama '71 shows with remarkable grace, The Troubles wasn't a battle between merely two combatants, but among multiple players, including several Irish Catholic factions that were fractious on the best of days, an Irish Protestant paramilitary force, and the British military.

A stunning piece of filmmaking as thrilling as it is intelligent, Yann Demange's feature debut miraculously distills the often Byzantine nature of the power politics behind The Troubles in a deeply intimate chamber piece about a single day in the life of a British soldier.

Set in 1971, the film stars Jack O'Connell (Unbroken; 300: Rise of an Empire) as Gary Hook, a working-class English soldier who is barely out of basic training when his squad of newbies is assigned to patrol the streets of Belfast.

Sent by the inexperienced, naive, upper-class Lt. Armitage (Sam Reid) to back up a police action by a particularly vicious group of cops from the Royal Ulster Constabulary, the troops are besieged by an angry mob of rock-throwing civilians.

Hook and a fellow squadie are separated from the other soldiers by young IRA upstarts who execute Hook's compatriot on the spot. Hook manages to escape but is left behind by the soldiers who retreat in panic.

So begins the odyssey that takes up the bulk of the film. On the run from the gunmen who must silence him before he can identify them, Hook tries to make his way across the city at night. The IRA leadership, meanwhile, has repudiated the killers and is on a hunt for them.

The danger increases when Hook runs into a group of fellow Brit soldiers led by Capt. Sandy Browning (Sean Harris) and Sgt. Leslie Lewis (Paul Anderson). These guys aren't regular army but work undercover as spies and provocateurs. They've no intention of helping Hook - who has witnessed them pull off one of the dirty, lethal tricks that seems to define their work.

O'Connell, who was barely 15 when he delivered a critically acclaimed breakout performance in This is England, is mesmerizing as Hook, a man of few words who has emerged from a dark, tragic childhood as a haunted, implosive figure.

On screen in every scene and virtually silent for the duration of the story, O'Connell owns the film with a carefully modulated physical performance that provides a beautiful counterpoint to the sparse dialogue. Demange's camera gives him ample space to work his magic.

Demange, a French director praised for his work in British TV (Dead Set, Top Boy), keeps '71 moving at a breathless pace while placing, with brilliant precision, several slow, introspective sequences that take us deeper and deeper into the hero's heart and soul.

This is a rare, almost-perfect work, harrowing, suspenseful, and penetrating.

'71 ***1/2 (out of four stars)

Directed by Yann Demange. With Jack O'Connell, Sean Harris, Sam Reid, Charlie Murphy, Paul Anderson. Distributed by Roadside Attractions.

Running time: 1 hour, 39 mins.

Parent's guide: R (violence, profanity, smoking).

Playing at: Ritz East, Carmike Ritz Center-Voorhees.