But even if it were the case that valuable information were obtained during or after the use of torture, what would it prove? Nobody has ever argued that brutality will never produce truthful answers. It is sometimes the case that if you torture someone long and mercilessly enough, they will tell you something you want to know. Nobody has ever denied that. In terms of the tactical aspect of the torture debate, the point has always been — as a consensus of interrogations professionals has repeatedly said — that there are far more effective ways to extract the truth from someone than by torturing it out of them. The fact that one can point to an instance where torture produced the desired answer proves nothing about whether there were more effective ways of obtaining it.
Excerpt from Glenn Greenwald – Salon.com.