By November 2005, three different federal judges had issued ironclad preservation-of-evidence orders in cases involving terror suspects and Guantánamo detainees. That was when the CIA elected to destroy tapes of the interrogations and waterboarding of two suspected Al Qaeda members. To the inherent criminality of torture, add contempt of court.

The revelation of those CIA videotapes and their destruction has inspired a leakfest in Washington and Langley, with fingers pointing everywhere and nowhere. “There are other people at the agency who know about this far better than I,” says CIA director Michael Hayden. Meanwhile, “other people at the agency” keep shifting blame between the legal office and the Directorate of Operations. The White House and Justice Department claim they advised the CIA to keep the tapes. But given George W. Bush’s passion for extralegal imprisonment and “extreme interrogation,” the agency had every reason to see mixed signals from Pennsylvania Avenue. Democratic Representative Jane Harman, informed of waterboarding and other outlaw interrogation practices in 2003, says she filed a classified letter of protest but “was not free to disclose anything.” But what secrecy oath requires public servants–not only Republicans but Harman, Nancy Pelosi, Bob Graham and Jay Rockefeller–to keep silent about systematic violations of US and international law?

As Emily Bazelon and Dahlia Lithwick write in a pertinent post on Slate, the destroyed videotapes would have had a profound impact on the Moussaoui and Padilla trials, the Guantánamo detainee lawsuits and the September 11 commission report. If that is true, then destruction of the tapes amounts to subversion of vital American institutions and is no sideshow but a central episode in the history of post-9/11 policy. Senator Joe Biden got it right: the CIA tapes’ destruction, and the violations of anti-torture statutes they recorded, require a special prosecutor. Only such an independent investigation will be free of the Bush Justice Department’s long entanglement with interrogation and torture policy, and the broader culture of complicity that ensnares everyone from anonymous CIA operatives to Congressional leaders of both parties.