In Sullivan' essay mentioned below, he describes the torture-through-prolonged-sleep-deprivation of Mohammed al-Qahtani this way:
During Qahtani’s interrogations, his refusal to drink and many days of sleep deprivation brought his heartbeat down to dangerously low levels; but even after he was urgently hospitalized for a day for dehydration to prevent his death, sleep deprivation continued—and was continuously used even as he physically deteriorated. An early FBI review of the interrogation of Qahtani found that the cumulative treatment led him to exhibit “behavior consistent with extreme psychological trauma (talking to non-existent people, reportedly hearing voices, crouching in a corner of the cell covered with a sheet for hours on end).” If you believe “extreme psychological trauma” is the same as “severe mental suffering,” then [Bush] ordered the prolonged and brutal torture of Mohammed al-Qahtani.
Now, there are several arguments to be made against torture, which I would think fall into three main categories: legal, moral, and practical. The first is pretty straightforward: does this kind of treatment of prisoners violate our domestic laws and international obligations? The answer is straightforward as well: yes, clearly.
The moral argument is less clear-cut, but anyone wanting to argue that treating a human being in the above fashion is ethically despicable probably has a pretty good case. One of the moral foundations of Western civilization is supposed to be respect for the integrity of human persons, no matter how guilty, and I can't think of an act that more thoroughly debases the very self of a person than does torture.
But what strikes me about the above passage is the practicality element. The argument that torture is not practical has two versions that I see: first, that torture produces a certain amount of quality intelligence that could not be attained through traditional means, but that benefit is outweighed by the deleterious effects of that torture on our credibility and soft power; second, that torture actually produces no intelligence that could not be otherwise obtained and in many cases actually produces lower quality intelligence through false confessions and general incoherence.
The passage above really does violence to the first version, the idea that torture does produce anything of value. By the end of the interrogation, al-Qahtani is talking to non-existent people, hearing voices, and otherwise hallucinating. What kind of intelligence does any one seriously expect a man in that state to provide? Who can read that and seriously think that any tiny needle of true and coherent information that might emerge from that mess would be worth the effort required to dig through the haystack of delerious ramblings of a man driven mad? No wonder the professionals are dismissive.