It is the duty of critics in war-movie time to wrestle with François Truffaut's old dictum that antiwar films are an impossibility—because cinema, by virtue of its kinetic energy, makes battle look like a blast. Directors, however, are under no obligation to remember this, and no one could accuse the filmmakers who've addressed Iraqi combat of making it seem overly exciting. Their war is a hell of insufferable dullness, populated by one-dimensional warriors. Paul Haggis pictured In the Valley of Elah's soldiers as traumatized zombies, Robert Redford imagined exploited martyrs in Lions for Lambs, Kimberly Peirce went with a pinch of both for Stop-Loss, and Brian De Palma—cut off in traffic by one too many "Support the Troops" bumper stickers, perhaps—decided in Redacted that the Army was populated by seething rapists. The fighting may continue, but the movies have kept the combatants at a distant remove. Theirs is but to do and die. Our job is to question why.

So it comes as a bracing sign when the hero of The Hurt Locker, an explosives expert played by Jeremy Renner, arrives at his new bomb squad in Baghdad and immediately starts making his own decisions. (After a summer dominated by machines, it is doubly encouraging when his first act is to fire the unit's remote-control robot.) This movie's director, Kathryn Bigelow, is an action-flick choreographer best known for the surfing-detective picture Point Break, and she isn't satisfied with aloof hand-wringing. Instead, she conjures Baghdad as an Old West frontier boomtown with high-noon showdowns in the streets—except the sheriff is wearing a moonsuit, and his adversary drives a car potentially packed with IEDs. We're shown right off what these buried weapons can do: An early detonation shakes the rust off cars and sends a specialist home in a square white box. The new man relishes the challenge. Renner, who looks like a chubby-cheeked Kiefer Sutherland, may play a "wild man" who has defused 873 bombs (his gambles madden his partners Anthony Mackie and Brian Geraghty), but the actor has an unaffected, compact grit; his muttered "Oh, Jesus" when uncovering a mess of wires is both a droll prayer and a preparation to engage.

The squadron doesn't pause to argue over why they've been deployed here, but as The Hurt Locker progresses, it begins to feel like a parable of U.S. interventionism. Renner's staff sergeant shoulders an unauthorized investigation, one that unravels until he's pointing his revolver at terrified innocents. "I'm looking for the people responsible," he says, and the sudden catch in his voice speaks for every conscientious American bewildered by what we've wrought with our liberation.

Once you sense this shared confusion, it is impossible to remain detached from The Hurt Locker. You are a soldier trying to foil one calamity before you get the call to prevent another calamity. You're surrounded by the work of evildoers (forget how George W. Bush abused and twisted that word; when you see a child's corpse taxidermied into a body bomb, you know somebody has done evil), and you know that you have an obligation to respond to this, because you were taught that looking away is a monstrous act of callousness. So you combine the best intentions of your heart with hilariously misconstrued "intelligence" and you race down blind alleys into suffering you couldn't even imagine when your conscience decided you had to get involved. And all you can say is, "I'm sorry, I'm sorry," as another human being is ripped to pieces while you turn to run away from the blast. And if you survive, you have to do it again, because now you're hooked on the jolt of certainty you felt for a second, before everything exploded into shit.

This is the experience of war. It is also the provenance of art. Both are the territory of The Hurt Locker, which is not only the first credible film about Iraq but merits serious consideration for the finest movie of the year. Kathryn Bigelow uses her capacity for action to make war exciting—and understands that this thrill is exactly what makes it addicting. The Hurt Locker is horrifying. It's hopeless. I want to go see it again.

SEE IT:

The Hurt Locker is rated R. It opens Friday at Fox Tower.