The thing about torture is that its main purpose, historically, has been to coerce confessions out of people. Why would the Bush administration want to do that? Well, maybe because they were looking for stuff like this: "Under torture after his rendition to Egypt, al Libi had provided a confession of how Saddam Hussein had been training al Qaeda in chemical weapons." Naturally, that information worked its way into Colin Powell's famous UN presentation. You remember, the one that only a traitor, a coward, or worse a Frenchman could fail to be convinced by. Equally naturally, it was false.
Matthew Yglesias is a former writer and editor at The Atlantic.