Thump thump thump! Boom boom! Bang bang! - and that's just composer John Powell's score. In Green Zone - Paul Greengrass' frenetic Iraq war movie, inspired in part by former Washington Post correspondent Rajiv Chandrasekaran's Imperial Life in the Emerald City - urgent convoys roll through the city, helicopters whip the hot Baghdad skies, important Pentagon dudes deplane at Saddam International Airport, and the good soldier portrayed by Matt Damon realizes that he, his men, and his country are being played for fools.

In the wake of the Oscar-winning The Hurt Locker - a far better film, and one with a less strident, less obvious agenda - Green Zone arrives looking strangely anachronistic. In part, this is because the film is set in early 2003, when the dust of the U.S.-led invasion was still whirring in the air. In part, too, it's because so many Iraq movies - with their house-to-house sorties, their wailing widows, their bitter Baghdad citizenry - have preceded it.

But the been-there/done-that feeling is mostly a function of Brian Helgeland's desperately busy screenplay, which tracks an intrepid Army officer's fruitless quest to find weapons of mass destruction - the MacGuffin that was supposed to justify the war - and cuts and pastes sound bites from George W. Bush, Dick Cheney, and the neocons into the script. When Greg Kinnear, as a Defense Department intelligence chief, shrugs away the anarchy on the streets with a terse "democracy is messy," the irony gets lost in the history.

And as Damon, bringing his Bourne gravitas (and box office) to the role of Chief Warrant Officer Roy Miller, hustles from one empty, dung-encrusted warehouse to the next, he rattles off a mantra of disillusionment: "This is no WMD site," "The intel is wrong," "Did anyone verify this story?"

This last question he asks of Lawrie Dayne (Amy Ryan), a reporter whose articles about the existence of WMDs were sourced from the most high-up and anonymous parties. While Dayne's Wall Street Journal byline is fictitious, the New York Times' Judith Miller's was not. The standard disclaimer, "This is a work of fiction and bears no resemblance to people dead or alive . . . "? Well, right, yeah, sure.

With the herky-jerky, handheld camera work and hiccup editing that marked his action sequences in The Bourne Supremacy and The Bourne Ultimatum, director Greengrass cuts a chaotic swath through his make-believe Baghdad (the movie was shot in Morocco and Spain). There's gripping, suspenseful stuff here, as Miller and his squad abandon the WMD hunt to chase down pro-Saddam conspirators, and as an Iraqi citizen-turned-interpreter (Khalid Abdalla - one of the terrorists in Greengrass' United 93) tags along, limping hurriedly on his artificial limb. The grim sights of hooded prisoners, of torture chambers and hired guns doing special forces' dirty work on clandestine missions, are contrasted with the country-club atmosphere inside the so-called Green Zone. Here, behind checkpoints and fortifications, the new corps of American diplomats, bureaucrats, and aides lolls poolside, ready to turn Saddam Hussein's capital into a beacon of democracy in the Arab world.

Cut to Bush's "mission accomplished" broadcast.

And cut to Damon, glowering mightily, as he trots through the Baghdad night trying to find the truth, as intelligence guys and Pentagon guys and Army guys prevaricate all around him.

"I thought we were all on the same side," he says to Brendan Gleeson, cast as the CIA's Baghdad station chief.

"Don't be naive," the CIA man says back.EndText