Donald Rumsfeld, it turns out, was born for the stage. In "Guantanamo," a drama culled from letters and public records, the playwrights Victoria Brittain and Gillian Slovo cast the defense secretary as a glib master of evasion who tells reporters that the president will decide when the war in Afghanistan has gone "past our due date" and who makes "beautiful, sunny Guantanamo Bay" sound as if it were the penal-colony answer to St-Tropez.

The play uses Rumsfeld's words against him. In the guise of actor Leo Erickson, he's portrayed here as the icy-veined spokesman for a policy the dramatists deplore: the open-ended detention of terrorism suspects, languishing in a torturous limbo, beyond the reach of international law. Embedded in a work that unabashedly makes a plea for some kind of humanitarian intervention, Rumsfeld is depicted as a figure of irredeemable insensitivity.

When an administration feels it is answerable to no one, the authors appear to be saying, why should a play have to be impartial? "Guantanamo" -- its subtitle is the ironic phrase "Honor Bound to Defend Freedom" -- is an edifying if one-sided take on the human toll exacted by a system that lacks a clear way to exonerate the innocent. In its regional premiere at Studio Theatre, the two-hour production comes across a bit dryly, owing to the flatness of the verbatim speeches and that op-ed air of an unchallenged argument.

Even so, if you harbor even the slightest unease about how the government is warehousing the detainees -- possibly the innocent along with the guilty -- you're likely to come away from "Guantanamo" feeling cleansed and alarmed. Given the latest revelations about secret overseas prisons run by our intelligence services, the play remains as topical as when it had its debut in London, to acclaim, more than a year ago. And with the Guantanamo detentions stretching ever longer into a seeming void, the need to remind Americans of what is -- and isn't -- transpiring there becomes all the more urgent.

As constructed by Brittain, a London journalist, and Slovo, a South African novelist, "Guantanamo" is a kind of tribunal, offering testimony from lawyers, human rights activists and relatives of both the detainees and those who died in the Sept. 11, 2001, attacks, as well as from the detainees themselves. Mirroring the design of the play's past productions, the set by Giorgos Tsappas conjures up a prison world of cots and metal fences. The inmates, in orange jumpsuits, are already onstage as we take our seats, and they remain there after the play's final words are spoken. Sentences without end.

From behind the chain-link fence, an inmate muezzin from time to time calls his fellow Muslim detainees to prayer, and the distinctive music of the faithful here acquires a poignant tone. It sounds like grief. Much of the play is consumed by the stories of three British detainees, Moazzam Begg (Kaveh Haerian), Jamal al-Harith (Andrew Stewart-Jones) and Bisher al-Rawi (Ramiz Monsef). Their paths to prison in Cuba are recounted for us simply and directly, in talking-head style, with Begg's story recalled by his heartbroken father, Azmat (Harsh Nayyar), and al-Rawi's by his embittered brother, Wahab (Omar Koury).

You're supposed to be appalled by the faulty assumptions that sweep each of them into the dragnet; al-Rawi, for example, is arrested in Gambia, where he and his brother were setting up a peanut-oil processing plant, and where an interrogator accuses the brothers of plotting terrorism. "So I told him, 'Okay, name two targets in Gambia that are worth blowing up,' " reports Koury's dumbfounded Wahab, who eventually is released. These tales could be the bases of latter-day screenplays for the Keystone Kops, but a weakness of the evening is that they are all told from the point of view of the accused. As unjust as the treatment seems to be, you're left to wonder at times whether some pertinent details are being withheld.

More resonant and persuasive is the argument articulated by Azmat Begg, Moazzam's dad, a patriotic British subject who has what seems an eminently reasonable request: Try his son, or release him. "If he is guilty, he should be punished," he says. "If he is not guilty, he shouldn't be there for a second." (Begg and al-Harith eventually were set free; Bisher al-Rawi remains in Cuba.)

Nayyar's polished performance as the anguished Azmat is the closest the production -- competently if unexcitingly directed by Serge Seiden -- comes to giving the audience an emotional touchstone. He seems the embodiment of helplessness. As Wahab, Koury has some fine moments, too, of barely suppressed ire. The actors playing the detainees themselves, however, are not especially vivid. Haerian's Moazzam Begg is a bit too remote. When Moazzam lapses into a paralyzing depression, suggested by his failure to acknowledge the call to prayer anymore, we're not able to commune as much as we need to with his profound sense of despair.

Still, the directness of the documentary-style "Guantanamo" is novel in a town in which an astonishing paucity of theater by the major companies attempts to talk back to power. On some level, yes, virtually every play is political. But it's refreshing to see and hear rhetoric on a stage without the veil of metaphor. Brittain and Slovo are doubtless thrilled to be making their case within shouting distance of the White House. It gives one pause, though, to reflect on the fact that in our deeply divided political culture, only those predisposed to considering the criticisms of "Guantanamo" are the ones likely to hear them.

Guantanamo: Honor Bound to Defend Freedom, by Victoria Brittain and Gillian Slovo. Directed by Serge Seiden; set, Giorgos Tsappas; lighting, Michael Giannitti; costumes, Reggie Ray; sound, Gil Thompson. With Yvonne Erickson, Dikran Tulaine, John-Michael MacDonald, Ramiz Monsef, Nafees Hamid, David Bryan Jackson. About 2 hours. Through Dec. 11 at Studio Theatre, 1501 14th St. NW. Call 202-332-3300 or visit www.studiotheatre.org.

Ramiz Monsef, left, and Andrew Stewart-Jones portray British detainees in Studio's one-sided but chilling look at the prison at Guantanamo.

Harsh Nayyar is affecting as Azmat Begg, the father of a British detainee.

Leo Erickson's Donald Rumsfeld uses the defense secretary's own words.