I don't always agree with Arizona Senator John McCain, but I certainly agree with what he has to say here. McCain was himself on the receiving end of torture, and he's aware of something that the naive tend to overlook: Torture can make people talk, but it can't make them tell the truth. In fact, I guarantee you that if you or I were tortured, we would reveal all manner of diabolical plots, anything we could think of whether made up on the spot or dimly remembered from an episode of Pinky and the Brain, anything to make the suffering stop.
I once read an article by a military officer who had undergone training on how to deal with being interrogated by an enemy, and that training included controlled use of "enhanced interrogation." He said that very few people in the program revealed anything important and accurate under such pressure. Where they slipped up was in other forms of interrogation not involving torture.
Sen. McCain also makes the point that there's little or nothing in the report that isn't already known or suspected by critics of the United States, so its power to inflame anger is limited. I would add two things to that:
First, there have already been horrific revelations, and except for the graphic Abu Ghraib photos none of them has caused much effective harm to the U.S., certainly not a mass of text.
Second, had the Senate not released the summary, that concealment would have itself have been an excuse to impugn the U.S.
If anything, the release of such a damning but honest report makes this country look better to people overseas. They already know we're not perfect. It impresses them when we have the guts to admit it.
Incidentally, contrary to what we keep hearing, the Senate has technically not actually released the full torture report (which runs thousands of pages), only a lengthy summary, one that was redacted at the request of the administration with input from the CIA.