In "Green Zone," Matt Damon is a soldier in the early days of the Iraq war, trying to find WMDs, hitting one dry hole after another.

"Who's giving us this intel?!" he screams.

The answer, I'm afraid, is Greg Kinnear, who's made a career playing shallow, insincere men, and whose presence here removes any doubt as to where the movie is going, or what it's up to.

"Green Zone" makes no claim to subtlety and is eager to use glad-handing Greg as shorthand for Bush Administration hucksterism - Kinnear is the head White House lackey in Baghdad, sending good men like Roy Miller (Damon) on WMD goosechases, while he attempts to install an ex-pat Iraqi as head of a provisional government.

We're meant to understand that the guy is Ahmed Chalabi, and when Amy Ryan turns up as a big-time journalist who flogged the WMD story during the run-up to invasion, we're meant to see her as New York Times reporter Judith Miller.

It's like a greatest hits of Iraq War screw-ups, complete with black-hooded torture victims being paraded past signs that say "no photos."

You want to laugh, and the book that purportedly inspired "Green Zone" ("Imperial Life in the Emerald City") was full of black comedy.

"Green Zone," though, does not have the temperament to muster a laugh, even a bitter one. It's directed by the documentary-trained Paul Greengrass ("United 93"), and it would be hard to find a more earnest filmmaker.

In place of humor, Greengrass (who directed the later Bourne movies) favors action, and sends Miller on a series of pell-mell missions through the chaotic city. Miller quickly gives up on the phantom WMDs, and concentrates instead on finding a Baathist general (Igal Naor) who holds the secrets to the WMD mirage.

There are no surprises here, story-wise, but it does give Greengrass a chance to go nuts with his famous method of shooting movies, which is to waterboard his director of photography with Starbucks coffee and send him out to shoot everything with a hand-held camera.

Humvees thunder through dark streets, and everything vibrates, and in case we miss the urgency of it, Greengrass pounds us with the world's loudest drum machine. When Miller disembarks, Greengrass chases him through narrow alleys, in and out of houses, over fences.

Greengrass' foot-chases employ the very same technique that Kathryn Bigelow used to stage an exciting chase sequence in "Point Break," oh, a hundred years ago.

She's since moved on to more elegant ways of re-inventing action, and was happy to show them off in "The Hurt Locker," on her way to winning an Oscar.

Greengrass is in a kind of suspended artistic animation, and the movie itself has the feel of something backed into a corner - a thriller that wants to thrill us with stuff we already know (it's a live-action do-over of Charles Ferguson's "No End In Sight").

The only mild surprise occurs in the closing moments, in a scene that complements the self-determination evinced in the recent Iraqi election.

Less surprising is Greengrass's final shot, a parade of Humvees racing into the distance, where oil fields line the horizon.