The first unassailably great film of 2007, this account of small-town Irish lads circa 1920 who teach themselves the basics of guerrilla warfare—in order to rid their nation of rifle-toting Brits—has striking parallels to America's ongoing jingoist adventures in Iraq. But director Ken Loach and screenwriter Paul Laverty, who took home last year's Palme d'Or at Cannes, never force or emphasize political points in The Wind That Shakes the Barley. They concentrate at first on the brutality of British soldiers attacking unarmed Irish country folk; the inevitable backlash against the occupying army; and then the passionate disagreements over the uses of freedom, which in turn lead to still more bloodshed. The filmmakers show us the ease with which liberators can become oppressors.

As the earnest young men ensnared in this cycle, Cillian Murphy and Pádraic Delaney achieve a level of realism rarely attained in movies. The conflict between these two Catholic supporters of Irish sovereignty feels reminiscent of Martin Scorsese territory; it's a Scorsese film made by someone who can actually direct. With one graphic exception, Loach relies mainly on sound effects and quick cutaways to convey the carnage of war. (Barley also serves as strong medicine to counteract the sugarcoated, closure-obsessed banalities all too prevalent in The Lives of Others.)

Loach, who 17 years ago made another film sympathetic to the IRA, the underrated thriller Hidden Agenda, understands there can be no "closure" in the wake of self-defeating compromises. The Irishmen in Barley live and die to establish a government of their own, yet when a Republican magistrate (an invigorating screen debut by a dark-haired actress named Fiona Lawton) rules against a weapons supplier, local followers of Sinn Féin conspire to overturn the verdict of her court. In the ensuing arguments, Laverty's script lays bare the fissures within the ranks. "Underneath, we're the same as the British," laments a survivor of the 1916 Easter Rising, and as you listen to the lacerating exchanges between people with common cause, you can see the wheels of civil war spinning. The single-minded pursuit of getting the British out of Ireland will be pushed to extremes, even if it entails (as it so often does) "the good guys" morphing into a version of their enemy.

It may be overreaching to claim that The Wind That Shakes the Barley resonates with the same heady intensity you get from reading Yeats, but I'll claim it; for a movie to be anywhere near that signifies a miracle of some sort.

Opens Friday, May 25, at Hollywood Theatre.