Even before the end of the Cold War, the CIA has gone to great lengths to obtain details on the new interrogation methods ("brainwashing") that the communists had developed. More details came out once the Soviet Union fell. The bottom line is that torture as most people think of it is now considered old fashioned and primitive. Or, to put it another way, torture is an unreliable art, while modern interrogation methods are a predictable science. Neither is pleasant, but the latter is more legal than the former, and leaves no physical scars.
Every time a major al Qaeda member is captured, the question of torture comes up. It's doubtful that torture, in the classic sense (think lots of pain) would ever be used by American interrogators. In fact, after a century of intense research and experience with all sorts of torture and interrogation, it's become common knowledge that pain based torture is only used when you haven't got skilled interrogators, or when you are dealing with a low level fellow who isn't a true believer and can be quickly motivated by the prospect of some extreme discomfort. What made painful interrogation pass has been the discovery of more subtle methods to make people talk. We can thank the nazis and several generations of communist interrogators for many of these new ideas. Something as simple as sleep deprivation and generally uncomfortable (but not painful) conditions can loosen the tongue of hard cases more easily than hot pokers, electric shock and pulling out their fingernails. Pain is easier to resist than extreme fatigue. It's been discovered in the last century, for example, that going for more than 24 hours causes most people to begin hallucinating and generally losing control of what they say. This is just the sort of state-of-mind a skilled interrogator can exploit.