Two recent American tragedies are referenced in movies this weekend. “Remember Me” is set in the months preceding the 9/11 attacks, and “Green Zone” is about a second calamity—the decision to invade Iraq in 2003. Paul Greengrass’ political thriller is easily the better of the two, though hardly the equal of his best films.

It’s fortuitous that the picture should be released just as Karl Rove’s book, which among other things tries to justify the invasion, is coming out. Rove, whose refusal to accept responsibility seems to be equaled only by his lack of shame, argues that the erroneous intelligence about WMDs, which was the stated justification for the war at the time (though the administration later offered other excuses), was an honest mistake. The premise of Brian Helgeland’s script, on the other hand, is that the information was literally manufactured to provide a plausible basis for the invasion. It doesn’t go so far as to accuse bigwigs in Washington of the decision to do so, but strongly suggests they were implicated in the fraud. That will undoubted bring it scorn from right-wingers, but one can argue that’s all to the good.

The premise is put forward in the form of an action thriller, set in Baghdad shortly after the taking of the city. Matt Damon plays Roy Miller, the leader of a squad assigned to find the dreaded WMDs. All the locations they search, however, turn out to be dead ends. Miller begins to suspect that the information they’re working from is flawed, though superiors assure him it’s based on absolutely reliable intel. His doubts, however, catch the eye of CIA bureau chief Martin Brown (Brendan Gleeson), who’s at odds with the administration’s man on site spokesman, Clark Poundstone (Greg Kinnear) over the proposed policy of purging the government of Ba’ath Party members and disbanding the army, which Brown thinks will lead to chaos. Poundstone, however, brushes aside the spy’s objections, intending to hand over power to a Washington-supported puppet, an exile named Zubadai (Reed Rawi), who’s been picked to preside over an Iraqi “democracy.”

Matters heat up when Miller’s informed by a helpful local, Freddy (Khalid Abdalla), about a furtive meeting of some of Sadam Hussein’s top officials and takes his squad to capture the men. They succeed in rounding up a few and killing a couple others, but the most important figure—General Al-Rawi (Igal Naor)—escapes. Happily the host of the meeting coughs up a book that identifies the general’s safe houses. But when Poundstone’s security forces swoop in to seize Miller’s prisoners for interrogation, the straight-arrow army guy, by now convinced the White House rep is not to be trusted, passes it to Freddy, who becomes his translator.

That’s just the set-up for a frenzied competition between Miller, working with Brown, and Poundstone to track down Al-Rawi, the one to learn how the information on WMDs could have gone so wrong, and the other to prevent the truth from getting out. The upshot is a long chase sequence that’s obviously designed as a complement to the North African one Greengrass and Damon pulled off so memorably in “The Bourne Ultimatum.” Unfortunately, it’s not as impressive, partly because it’s shot at night, but also because it’s not choreographed with the same degree of precision and clarity. (It does, however, end with a bang.)

Part of the fun of “Green Zone” is linking many of the characters to the historical figures they represent. Zubadai is Chalabi, of course, and Amy Ryan as Lawrie Dayne, a Wall Street Journal reporter who pushed Poundstone’s case for WMDs on the basis of intel from a high-placed source code-named Magellan, is The Times’ Judith Miller. As for Poundstone, he’s not Paul Bremer, who’s specifically mentioned as his superior, but is a stand-in for every cocksure Bush Administration neocon who pushed the invasion—Paul Wolfowitz, perhaps.

And Greengrass, working with cinematographer and editor Christopher Rouse, uses his patented edgy, hand-held style to infuse the picture with a high-octane energy level. The visual crew—production designer Dominic Watkins, art directors Mark Bartholomew, Mark Swain and Frederic Evard and set decorator Lee Sandales—work wonders in transforming locations in Europe and Morocco into facsimiles of the Iraqi capital.

It’s unfortunate that the plot doesn’t quite measure up to the presentation. As Helgeland works the convolutions out, there’s a cut-and-dried quality to the proceedings; the connections click rather too easily into place—a bit of ambiguity would have been welcome. (The situation isn’t helped by the casting of Kinnear, who’s all too identifiably a sleazebag.) And the “Three Days of the Condor” ending isn’t merely disappointing; in view of the historical reality, it’s absurdly optimistic.

On the other hand, as in the “Bourne” pictures Damon holds the screen as an action star more thoughtful than most, and Gleeson has a fine time as the grizzled CIA vet. (Like Ray Winstone in the recent “Edge of Darkness,” he comes very near to stealing the show.) As the conflicted Freddy, Abdalla is bleakly amusing and poignant, and Naor is a commanding presence as Al-Rawi.

Among recent spy thrillers, “Green Zone” easily bests “Body of Lies,” which tried for the same mixture of topicality and excitement but came up short. And while compared to Greengrass’ finest movies it’s a minor effort, it offers enough excitement to pass muster—especially since its basic argument, provable or not, carries a real punch.