"Burning tapes, destroying evidence, I don't know how deep this goes," said Sen. Chuck Hagel (R) of Nebraska, a member of the Senate Intelligence Committee, on CBS's "Face the Nation." "Could there be obstruction of justice? Yes," he said. "How far does this go up into the White House? I don't know."
The claim that they were destroyed to hide evidence of waterboarding is preposterous and just a cover story.
The official story is that they were destroyed to protect the identity of the interrogators. That is the preposterous cover story.
The official (mostly Democratic and center-left) critique of the cover story is that they were destroyed to hide evidence of torture--not so preposterous at all, since it was done at a time when Congress was demanding some scapegoats to be held accountable for the mess at Abu Ghraib. Shredding evidence is standard procedure these days for the Bush crime family and its allies.
Here's a much more likely reason;
Destroyed tapes contained "Rosetta Stone of 911"
[snip] Zubaydah laid out details of how he and the al Qaeda hierarchy had been supported at high levels inside the Saudi and Pakistan governments.
That would be a "much more likely reason" if it were true. But we have no way to confirm that it's true. Posner obviously doesn't identify his source, but there's no corroboration, so that could be disinformation as easily as any other story. (Truly skilled conspirators provide phony "conspiracies" to attract the attention of those who are skeptical of the vanilla cover stories. For example, if people who want a better explanation of 911 than the official cover story start looking to Saudi Arabia to find it, those inside the U.S. government who abetted the attacks would get less scrutiny.)
This is the same Gerald Posner who wrote "Case Closed", the book in which he couldn't find any flaws in the "lone nut" theory of JFK's assassination. After that kind of arrogant absurdity, I have a hard time taking anything he says seriously.