In my response, I said, essentially, that torture does, indeed, work – for some criteria of "work".
Painful techniques for interrogating witches, and trials by ordeal, may not have been any good at all for establishing guilt or innocence, but as show trials may have been very effective at giving people "closure". (On Star Trek, Deep Space Nine, we meet the Cardassians, whose trials are show trials. They're scripted in advance, and the winner and loser is known before the trial even starts. I suspect this was stolen from an Earthly culture.)
Torture serves to ensure that the person cast in the part of the guilty party is seen to have confessed guilt, and to have been properly punished.
As for obtaining information, in the context he addresses, I'll stipulate that pecunium is 100% right. Torture will not induce soldiers trained to resist to divulge sensitive information for at least 24 hours, after which it will be obsolete. However, this involves assumptions that may not apply to terorrists – "soldier", "trained to resist", and "information becoming obsolete within 24 hours".
Finally, these discussions are pretty close to meaningless until you have some idea of what constitutes "torture". We know what the BTK killer did to his victims was torture. But I've also seen it argued that a prosecutor, threatening a first-time offender with hard time unless he pleads guilty in a plea bargain arrangement is also torturing his victim.
Bill Keezer calls attention to Trinquier: Modern Warfare: A French View of Counterinsurgency, which says, among other things:
"The soldier, therefore, admits the possibility of physical suffering as part of the job. The risks he runs on the battlefield and the suffering he endures are the price of the glory he receives."
If the prisoner gives the information requested, the examination is quickly terminated; if not, specialists must force his secret from him. Then, as a soldier, he must face the suffering, and perhaps the death, he has heretofore managed to avoid. The terrorist must accept this as a condition inherent in his trade and in the methods of warfare that, with full knowledge, his superiors and he himself have chosen."
It seems like a devil's bargain: tell all or you'll be tortured, and perhaps killed. Yet, the enemy soldier across the field is offered the same choice: surrender or be killed, perhaps painfully. The difference is that one encounter is planned out in excruciating detail, and the other isn't.
Bill's comment is:
By linking the issue of torture as an ordeal equivalent to the battlefield risks avoided by terrorists but endured by regular soldiers Trinquier adds a dimension I have not seen discussed elsewhere. I am not sold on the idea but I do think it has sufficient merit to get greater consideration.
In any event, Senator McCain has been adding an anti-torture bill to other bills as a rider. He intends to keep doing this until it passes. Wretchard at The Belmont Club has had some open comment threads on the topic, and one post where he offers the following prediction:
I'm going to make a personal prediction. The number of incidents involving the torture of terrorist suspects will increase after the McCain Amendment, or something like it, is passed. There will be a fall in the number of interrogation incidents in US custody. It may even become zero. However, there will be a corresponding increase in torture incidents involving agencies of other governments, including European governments, all of whom will fully subscribe to every piece of human rights legislation which can be imagined, but who in practice will simply do what they want.
If we need information from captured terrorists, and the restrictions on torture – including "degrading treatment" are too strict, it will be easier to allow third parties to take over the job. Our hands will be clean, but a lot more dirt will be generated.
This is a specific case of the law of unintended consequences. McCain sponsored a law that was supposed to get huge wads of money out of politics, and make it less of a rich man's sport. Instead, it made things so that only millionaires could run, at least until the 527 groups formed. Those turned out to pour far more single-issue money into politics than was ever found before.