This topic is anything but simple. It is going to be hard to comment on it in less than 20 pages, but here goes.
It is becoming pretty clear that Abu Zubaydah, a suspected islamic terrorist, was subjected to noise, stress positions, freezing temperatures, isolation, and waterboarding, in efforts to get him to talk to CIA questioners back in 2002. This interrogation did get important results from a USA perspective: Zubaydah's admissions resulted in the later capture of Khalid Sheik Mohammed, the mastermind of the 9/11 attacks. How do we know this? Anonymous U.S. officials have admitted it. Is there any proof? Well, there WAS proof, until 2005, when Jose Rodriguez, the head of the CIA's clandestine directorate of opeations, decided to destroy the tapes of the interrogation. No proof, no crime?, well depends on your point of view. is waterboarding torture? Well, Michael Mucasey, our brand new US Attorney General, has refused to term it torture, but hey, you would call it torture if you were stropped down with somebody asking you questions while holding your mouth closed and pouring water onto a cloth over your nose. It's simulated drowning if you are the guy asking the questions- if you are the guy on the receiving end, it's REAL drowning. And it goes on and on, all day and all night, until you talk. From his viewpoint the questioner is the terrorist now- everyone is afraid of drowning.
I do not have easy answers to this. But here are a couple items for your consideration. First, there are legal ramifications. The fact that the only record of the interrogation has now been destroyed complicates efforts to prosecute Zubaydah through the legal system. Zubaydah's testimony against Jose Padilla is also devalued by this discovery. Federal Judge Leonie Brinkema said that she can no longer trust the CIA. That messes things up, when most of the case depends on trusting the CIA. Ultimately, it is hard in a free society to handle imprisoning the terrorists without legally admissible evidence, and evidence gained by torture is not really legally admissible.
Item #2: what if somebody should take prisoner a high ranking US military officer and subject him to waterboarding? How do we argue that we did not do it first when it is perfectly obvious that we did? Okay, we can argue that we torture people out of goodness and niceness and to make the world a better place, while our enemies are just out to cause trouble. The problem with that argument is that the Geneva Convention which we signed strongly disagrees with that "end justifies the means" argument.
Complicating this whole thing is politics of course. In 2002, virtually nobody argued against cruel treatment of the 9/11 suspects. Even Democrat politicans at the time declined to raise objections. More recently, politicians and the public have stepped back and wondered if these techniques are defensible in the long term. John McCain, who was on the receiving end of quite a bit of such treatment back when he was a POW in North Vietnam (and can no longer lift his hands above his shoulders as a result), has strongly argued against torture, partly on the basis that it makes it much harder to argue that Americans imprisoned by foreign powers should be treated humanely.
Like I say, this is a tough issue. But let's be perfectly clear on one thing. We can no longer argue that terrorism happens in the real world, but torture of terrorist suspects by anonymous U.S. military or CIA officials is imaginary. It happens. Are you okay with it?