Aside from the legalities, the CIA does not believe outright torture produces reliable results and has never used it. Scaring prisoners with waterboarding is another matter. Waterboarding led to a takedown of key al-Qaida operatives when they were planning more attacks. If waterboarding really were torture, the military would not use it on its own special forces as part of their training in case they are waterboarded after being captured.
Many well-intentioned people, including Sen. John McCain, have described waterboarding as torture. But as defined by the dictionary, torture is infliction of pain. As used by the CIA, waterboarding entailed placing a cloth over the face of the subject and pouring water over the cloth. The technique creates the sensation of drowning and therefore fear, but it is painless. The individual awakes the next morning feeling just fine.
In fact, as we've noted, contrary to Kessler's claim that waterboarding victims are "just fine" afterwards, there is evidence that waterboarding does result in lasting physical or psychological damage.