A documentary by Alex Gibney. Rated R.

The driver piloting the runaway death trap in this Oscar-winning documentary has a middle name starting with W, although he is crammed into the front seat with Dick “So What?” Cheney, Donald “Stuff Happens” Rumsfeld, and other cowardly enablers from both U.S. parties.

The title of this searing and smoothly made effort also refers to another driver, a young fellow named Dilawar, the car-nut son of an Afghan farming family. In 2002, with America still in a kick-ass mood, Northern Alliance warlords handed to Yank soldiers (sold is a more accurate description) a few dusty Pashtun speakers they claimed were behind a rocket attack. This is how a routine cab ride to the countryside led to Dilawar being bound, beaten, tortured, terrorized, and ultimately murdered in his cell.

Such is not merely the conclusion of writer-director Alex Gibney, who last turned his laser light on Bush cronies in Enron: The Smartest Guys in the Room. It is found in official U.S. army documents Gibney (who also narrates) fought to get, and which were covered up at every level of the increasingly opaque chain of command. That it sticks to verifiable facts is what makes the movie so compelling and useful, because the filmmakers unfold a much larger tale. That tale extends to Klaus Barbie–level horrors at Abu Ghraib and Guantánamo—with witnesses including angry state department and Pentagon veterans, as well as the soldiers who did the killing.

The film should be used as evidence in war-crimes trials in The Hague. That’s not going to happen, of course. At the very least, however, former POW John McCain (against torture until he started running for president) might want to watch Taxi to the Dark Side—and then explain again what it means to be an American.