Of the terrorism suspects being held indefinitely on a military base in Cuba, a character in a new play about the detainees puts it succinctly: "Let 'em rot," he declares. It's hard not to endorse this sentiment, especially if your Sept. 11 grievance is familial -- the actor is playing the brother of a World Trade Center victim -- or if the attacks affected you in some other intensely frightening or personal way.

Yet in spite of lingering anger or residual scars, you may find your mind-set profoundly challenged by "Guantanamo: 'Honor Bound to Defend Freedom,' " which opened last night at the 45 Bleecker Street Theatre. The disturbing thesis of this moving documentary-style work, compiled from letters, interviews and public testimony, is that victimization did not end with the terrorist acts, that paranoia, bureaucracy and prejudice were the poisonous ingredients leading to the lengthy imprisonment in Cuba of a number of hapless innocents.

Skillfully assembled by two women, British journalist Victoria Brittain and South African-born novelist Gillian Slovo, "Guantanamo" is unreservedly agitprop: What's condemned here unequivocally is the Bush administration's decision to hold several hundred men in the prison in legal limbo, not as inmates charged with crimes or as prisoners of war, but in a vaguer category, out of reach of the world's courts. The cases that the dramatists highlight give voice to several Guantanamo inmates, men about whom most of the American public has heard virtually nothing. Their stories, of course, cast the policy as draconian and mindlessly, heartbreakingly inhumane.

Still, even if you are inclined to chalk up some level of governmental overreaction as the inevitable product of this unorthodox war, you will find it difficult to dismiss the evidence of "Guantanamo" with a stony salute to the interests of truth, justice and the American way. It's impossible to give the cold shoulder to the suffering of the falsely accused.

"Guantanamo," which focuses on the stories of a handful of British Muslims scooped up in dragnets and shipped off to confinement at Guantanamo Bay, was the talk of London when it was unveiled in May this year by Tricycle Theatre. With a new American cast and fiercely up-to-the-nanosecond topicality -- its arrival precedes the opening gavel of the Republican National Convention here by a mere few days -- the piece makes a claim on a prominent place in the American conversation. On the sidewalk in front of the theater after the performance, in fact, you could hear some of those conversations taking shape.

Like "The Exonerated," a play that uses the testimony of wrongly convicted men and women who were freed from death row to present an argument against capital punishment, "Guantanamo" follows the rule book of an increasingly popular style of political theater that relies entirely on the verbatim declarations of real people. The virtue of presenting authentic speech is also a potential hazard: The novelty of copious everyday verbiage on a stage -- ums, ers, uhs and all -- can wear on you in a hurry. And the flatness of a politician's formal utterances or a terrified father's digressions can sap the energy of a production, regardless of how compelling the theme.

"Guantanamo" falls prey at times to this problem, particularly during the first act, in which one detainee's father (Harsh Nayyar) and the brother of another (Ramsey Faragallah) dot the i's and cross the t's of the sad true stories of Moazzam Begg (Aasif Mandvi) and Bisher Rawi (Waleed Zuaiter). Begg, a British citizen of Pakistani origin, was picked up in Central Asia, where he was working as a teacher, by Pakistani and American agents; Rawi, an Iraqi refugee living in Britain, was arrested in Gambia, where he and his brother were setting up, of all things, a peanut oil processing plant.

Embroidered with commentary from lawyers and politicians -- there's a funny cameo by a vain, haughty, self-assured Donald Rumsfeld, played to perfection by Robert Langdon Lloyd -- the tales pick up speed in the second act, as they expose the toll exacted by the hardships of Guantanamo. In letters home, the inmates gripe about the bad food, the interrogations, the spiders in the cells, but what strikes you as most cruel and devastating is their absolute uncertainty about the length of their imprisonment. In the case of Begg, played with a wondrous depth of feeling by Mandvi, the shapelessness of time proves too much, and he lapses, shatteringly, into a kind of inconsolable derangement.

The directors, Nicolas Kent and Sacha Wares, employ minimal artifice; along the left and right edges of the playing space, set designer Miriam Buether has erected a row of metal cages housing inmates in orange jumpsuits. Other actors are seated at tables or perched on cots. The aural accompaniment is the voice of man chanting prayers in Arabic, which comes to represent the only reassuring ritual in the inmates' lives.

Inexcusably, some of the performers don't seem to know all their lines yet, but others, comfortably mastering the language, provide moments of disquieting revelation. Kathleen Chalfant and Steven Crossley are excellent as legal-eagle inmate advocates and Jeffrey Brick delivers a sensitive portrayal as the brother of the Sept. 11 victim who is wrestling with his conscience over his feelings about the detainees. Letting all the detainees rot, he acknowledges, is not a solution. "Surely, they could figure out which ones are dangerous," he says. "Guantanamo's" worthy contribution is to compel us all to wonder the same thing.

Guantanamo: "Honor Bound to Defend Freedom," by Victoria Brittain and Gillian Slovo. Directed by Nicolas Kent and Sacha Wares. Sets and costumes, Miriam Buether; lighting, Johanna Town; sound, Bill Grady. With Andrew Stewart-Jones, Maulik Pancholy, Joris Stuyck. Approximately 2 hours. At 45 Bleecker Street Theater, Manhattan. Call 212-307-4100 or visit www.ticketmaster.com.

Kathleen Chalfant plays a lawyer who advocates for detainees in "Guantanamo: 'Honor Bound to Defend Freedom.' " Harsh Nayyar, left, as the father of one detainee and Ramsey Faragallah, rear, as the brother of another, with Maulik Pancholy in the moving "Guantanamo." Aasif Mandvi plays detainee Moazzam Begg with a wondrous depth of feeling for his plight.