I figure torture is anything that is used to force you into doing something you would rather not do. So is waterboarding torture? Of course. But is it a good kind of torture? You bet it is. No physical scars - just a surefire way to get needed info from the bad guys.
I think we need to use it on occasion. It would seem that torture exists in varying degrees. Some of the considerations would be permanent damage, amount of pain or discomfort, length of the torture, period of recovery, offering or not offering medical attention, physical or psychological.
It would seem that all of these factors would be considered and that we should have a range of tortures available for the situation and the resistance of the person being tortured.
I can't wait for the first death caused because we pussfooted around a suspect who wouldn't talk and people died.