Since we cant even agree on what torture actually is, I think "what ifs" can be very relevant. Is it safe to assume that since you ask when traditional methods havent worked that you think that they always work?
You and I may disagree on what constitutes torture, but the treaties and conventions that the US is a signed party to are pretty clear. We would not have signed if we didn't agree with them. There is precedent in US law as well, as after WW2 one of the war crimes charges that we leveled against the Japanese was the use of waterboarding against American prisoners. In addition the State Department defines "submersion of the head in water" as torture, and the difference between that and waterboarding is simply semantics as they both constitute simulated drowning.
I only think "what if" scenarios are relevant if they are based in reality. The "24" scenario only occurs in Hollywood and it certainly was not the case with the guys we tortured because if it was you can bet we would have heard about it as a justification. In the real world you don't torture people because you know what they know, you torture them because you
don't know what they know. And if they really don't know what you think they might know(which you have no way of knowing for sure), they'll make something up just to get you to stop.
As far whether or not traditional methods always work, I have seen no evidence to suggest that they don't. 9/11 itself could have been prevented by traditional police work if the right people had been paying attention to the right signs. The clues were all there, but nobody put them together.
We will never get the full stories on what happens behind those closed doors. There are "claims" that the methods used in this case did do good, but since only selected documents were released, we may not get that evidence one way or the other. You say we DO know that there was torture. Well then, punishment is in order. End of story.
You still didnt answer the "what if" though. What if regular ways dont work? What then? Where are the lines drawn? If there really was a plot on Los Angeles and someone holds vital info, where do you draw the line?
Like I said above, I have a hard time giving credibility to the "24" scenario. If we already know the target city and the approximate time of the attack, we're pretty much 90% of the way there. At that point I have faith that we have enough info and resources to foil the plot without torturing anyone.
Speaking strictly for myself, I could never torture another living thing, under any circumstances. 20 or maybe even 10 years ago I might have given you a different answer, but as I've gotten older I see the world differently. Probably just getting soft