If you believe that far-sighted statesmen launched a just and prudent war in Iraq, deterring the world's terrorists as a happy by-product, David Hare's new play may anger you. The dramatist has had the gall to raise serious doubts about the wisdom and honesty of both the coalition's leaders. If you take a different view of recent events, you may appreciate a play which strikes me as hard-hitting yet balanced enough to acknowledge, say, Tony Blair's desperate attempts to legitimise a dubiously legitimate war. Why, Hare even lets an actor give a long, angry speech about the "racism" of tolerating Saddam's treatment of his fellow Arabs.

So much lofty comment preceded the opening of Nicholas Hytner's production of Stuff Happens -Robin Cook proclaiming himself powerfully moved by Hare's account of a "misadventure", Ann Widdecombe comparing his play to Nazi-style propaganda -that maybe I should now limit myself to discussing the staging. But that would be hard, because this is even simpler than it was for Hare's recent railway documentary, The Permanent Way.

Indeed, it mostly consists of figures in suits discussing policy round tables or simply addressing the audience: prime among them, Alex Jennings's out-of-depth Bush, Nicholas Farrell's flummoxed, hapless, bleating Blair and Dermot Crowley's frighteningly confident Rumsfield, who emerges as the thinking man's Genghis Khan or maybe the unthinking man's Kissinger.

The title comes from Rummy's casually brutal remark about the looting of Baghdad.

But Hare's prime point is that neither he and the other neocons foresaw, tried to foresee or even wanted to foresee the "stuff" that happened after the war was superficially won. Smug remarks about oppressed people welcoming liberators with flowers were the best they could do. Their real agenda was to demonstrate America's post-9/ll power by taking out a supposedly easy target -and, despite Colin Powell's qualms, they carried a gullible president with them.

Joe Morton's Powell is Hare's hero, avid as he is to avoid a war he feels is morally unjustified and politically foolish, but the perhaps unintended effect of his articulate passion is to leave us wondering why he didn't have the consistency to resign. Wondering, too, about the accuracy and therefore the authority of a play whose author admits that he's "used my imagination" to fill in the bits not on public record. And yet I often felt: yes, this is how it was.

The inexorable slide to war is carefully chronicled: trans-atlantic calls to an increasingly compromised and irrelevant Blair ("that preacher on top of a tank" as Des Barrit's tough, crude Cheney calls him), arguments with the French, and all.

And the piece ends, pointedly, with a rare voice from Baghdad. We know how many Americans have died, but how many Iraqis, how many civilians? That's a question our leaders have yet to answer.