Bush speechwriter Marc Thiessen's full-throated defense of the previous administration's use of water-boarding has brought him into fierce conflict with Jon Stewart, the New Yorker's Jane Mayer, and, most spectacularly, liberal blogger Matthew Yglesias. Now Thiessen is hitting back. In a lengthy National Review column, Thiessen dubs Mayer's review of his book to be "A dishonest, error-filled review provides a textbook case of how the Left smears the CIA and its defenders." Going point-by-point through Mayer's argument, Thiessen concludes:

I have brought facts to the table, information that undermines the torture narrative they have made careers of spinning. For years, critics like Mayer could level any unfounded accusation they wanted against the CIA, confident that those who could challenge them were powerless to respond — because the answers were classified. But then Barack Obama declassified reams of documents revealing the secrets of the CIA program. He did enormous damage to our national security, but he also liberated those of us familiar with the intelligence  on CIA interrogations to speak out. As a result, Mayer is no longer free to make baseless accusations without challenge or consequence.

No wonder she’s upset.
Enter Conor Friedersdorf, who goes point-by-point through Thiessen's article. Well, the first bit, anyway.
he purports to defend his own position about enhanced interrogation, including waterboarding, by selectively quoting people who turn out to argue that either enhanced interrogation generally, or waterboarding in particular, shouldn’t be used and do more harm than good. That he neglects to mention their words when they are contrary to his own arguments is telling. And we’re only three short paragraphs into Mr. Thiessen’s article.
Marc Thiessen argues that his book counters all of Friedersdorf's points.
It’s all in there — though apparently these days critics on the left don’t feel they need to actually read a book before they criticize it.

The bottom line is that critics like Mayer want to have it both ways: They want to say (a) we should not use these techniques and (b) they didn’t work anyway. As even Obama administration officials admit, the second part is simply not true.
Friedersdorf responds at great length. Here's one bit of his detailed response:
Mr. Thiessen persists in acting as though whether “enhanced interrogation” works is a matter of proving that in some individual instances information was elicited that saved American lives. Before we granted that possibility for the sake of argument. Now let’s grapple with that narrow matter. Even proving that American lives would’ve been lost but for these techniques — a difficult thing to demonstrate — wouldn’t salvage Mr. Thiessen’s project, given other objections just listed.