WITH The Wind That Shakes the Barley, Ken Loach delivers his strongest and most compelling work yet. Maybe some of the credit should go to Cillian Murphy, the most commanding actor Loach has ever had in his movies, or maybe Murphy is just the best-looking subject since the young Terence Stamp starred in Loach's Poor Cow some 40 years ago.

Other directors have exploited Murphy's unnerving handsomeness for suspense and horror, but he gives Loach's newest film a center. Usually, Loach avoids the center, in cinema as in politics; his recent experiments with amateur and semiamateur actors worked, but at the cost of subtle revelation of character. (Loach films political meetings with more genuine ardor than he does love scenes.)

As in Loach's Spanish Civil War drama Land and Freedom, the story follows a skirmish between liberals and radicals. But The Wind That Shakes the Barley is a much less simplistic film than his Spanish story. I came out of Neil Jordan's Michael Collins, for example, bewildered by the struggle between Eamon de Valera and Collins and holding unwanted thoughts like, "I'm glad that revolution didn't interfere with Julia Roberts getting her hair done." Using a keen screenplay by Paul Laverty, Loach takes the tangled subject of Ireland in the 1920s and presents us with a clear but nonpartisan account. The film, set in the middle of the British crackdown just after World War I, opens with a hurling match, a rough-and-tumble game on the green. The players are scattered by a squad of vicious English soldiers—the dreaded "black and tans"—who treat the match as a forbidden public gathering. When one of the players refuses to cooperate, he is murdered.

Damien (Murphy) had been on his way to London to study, but the incident haunts him. Seeing similar brutality at a train station, he enlists in the fight against England. Eventually, the British are chased out by a combination of guerrilla war, boycotts and passive resistance. Ireland wins its freedom, but at the cost of continued acknowledgement of the British crown, a compromise solution enforced by the threat of renewed war. Damien's brother, Teddy (Padraic Delaney), decides to work within the system to try to steer an independent path for Ireland. Damien, who has given up so much for the revolution, refuses to compromise.

We know that the island never escaped the division between those who tried the legal fight and those who became insurgents. We know that the gravity of England exerted its same old pull, and that the grind of class war would consume generations to come.

Americans, sentimental if not-too-discerning patrons of the Irish cause, think of the fight as romantic. Loach schools us a little by catching Damien's heart-sickness. Even the heroic missions prove disgusting. Being a man butcher is worse than being a pig butcher. Murphy's physical grace leads us through some wrenching scenes. Possibly the Saw series or Abu Ghraib gave Loach the strength to get very graphic in an interrogating British sergeant's game of pliers and fingernails.

Loach's Ireland looks like both a place you'd love to bicycle through and hate to stay. We see some flashes of the famous 40 shades of green, mostly in a rich person's garden. But mostly, we get stones, fog, coarse bushes and poor pubs. Filming in County Cork, Loach catches the Wild West rawness of Ireland in 1920. No wonder the Irish were at home on the American frontier. Incidentally, the film's title comes from a patriotic ballad that's every bit as comfortless as "Streets of Laredo." (The barley patches apparently have the same significance as poppies in World War I poetry; wild barley patches grew on the unmarked graves of partisans killed by the British.)

Hemingway's "grace under pressure" ought to extend to an artist depicting war. His first duty is not to lose his civilization even if everyone around him has lost his or hers. Partly what delayed the arrival of this film, even after it won the Palme d'Or at Cannes, was Loach's refusal to let the heat of battle warm him. Audiences prefer 300-style wargasms to skulking guerrilla fighting we see in the training scenes of men crawling through the wet shrubs, using hurls (the Irish proto-hockey stick) as dummy weapons. This war is hard work. A gang of men emerges from the thick mist, in cloth caps and overcoats, with rifles slung over shoulders; except for the guns, they might as well be road menders.

The Wind That Shakes the Barley includes something that may never have been seen in a movie before: a group of armed insurgents hiding on the slope of a hill, knowing that they have to hold their fire if they want to fight another day. To them, military discipline means staying concealed. All they can do is witness as a young partisan girl on the valley below them has her head shorn and British soldiers burn her house. It's the wartime situation Goya summed up in one line: "There is no remedy."

Our movies usually tell us that war exalts the individual, making us heroes. Loach reminds us that so much of war is being in a situation where everything is out of your hands, including your death.

The Wind That Shakes the Barley (Unrated; 127 min.), directed by Ken Loach, written by Paul Laverty, photographed by Barry Ackroyd and starring Cillian Murphy, opens April 13.

Send a letter to the editor about this story.