Sometimes the truth hurts. Sometimes it's excruciating. Alex Gibney, who made compelling drama of the most heinous corporate debacle before the subprime meltdown in "Enron: The Smartest Guys in the Room," now turns to U.S. interrogation practices in the Mideast and Guantanamo. His Oscar-nominated documentary "Taxi to the Dark Side" is a searing critique of the dangers of unmonitored power in the hands of a few individuals, be they at the bottom of the command chain or the top.

The film begins on an arid road in Afghanistan where Dilawar, an innocent rural taxi driver, was swept up in a search for terrorists. Gibney presents evidence that this is commonplace. Most detainees at Guantanamo and Bagram Air Base were not captured by American soldiers, but fingered for cash rewards by Afghan and Iraqi tribal rivals, personal enemies and even competing opium growers.

Dilawar vigorously protested his imprisonment at Bagram. To shut him up, his guards pummeled his legs with knee strikes and batons. Shortly afterward, he died. The military autopsy ruled it a homicide, noting that his legs were so thoroughly "pulpified" they might have been "run over by a truck." The guards, decent men we meet in on-camera interviews, were merely following the guidelines they had been given.

Gibney, whose father was a Navy interrogator in World War II, begins with this single tragedy, then moves outward with an inquiry that reaches Washington's highest officials. As Vice President Dick Cheney told the nation on "Meet the Press" in 2001, "It's going to be vital for us to use any means at our disposal, basically, to achieve our objective." That includes rejection of the Geneva Conventions, simulated drowning techniques favored by medieval inquisitors, denial of traditional legal protections for suspects and grants of immunity to government officials for crimes against humanity.

The argument for such methods usually involves hypothetical ticking-bomb scenarios in which a tortured terrorist divulges information that saves millions of lives. But FBI experts and psychological researchers insist that torture is ineffective at getting the truth. It's also opposed by Sen. John McCain, R-Ariz., the only politician in either party to have endured torture (in a North Vietnamese prison).

While Gibney clearly has a point of view -- cool, righteous anger -- he is a fair-minded reporter, giving the legal architects of these policies screen time to rebut criticism and explain their goals. As our society searches its conscience for the correct balance between preserving American lives and upholding American values, Gibney offers a crucial perspective to counterbalance the influence of eye-for-an-eye gut instinct and fictionalized, infallible torture techniques on "24."

Colin Covert • 612-673-7186