For those interested in the controversy surrounding the resort to torture in general and waterboarding in particular an ABC interview with former CIA agent John Kiriakou may prove instructive. Kiriakou doesn't like it, he'd prefer we not do it, but nevertheless, not only does he claim it is effective but in some cases it's morally necessary (my gloss on his words).
According to Kiriakou waterboarding has been employed in only a handful of cases, one of which was that of Abu Zubaydah, a high ranking al Qaeda terrorist caught soon after 9/11. Zubaydah was subjected to the sensation of drowning for 35 seconds after which he told the interrogators everything he knew and the intell was used to prevent dozens of terrorist attacks and save perhaps hundreds of lives.
The question those who believe torture to be absolutely wrong have to be asked is why they think it wrong to subject a mass murderer to 35 seconds or less of physical discomfort, after which he is perfectly unharmed, in order to save his victims from being blown to bits. What moral calculus could possibly lead us to conclude that it is better to let perhaps hundreds of women and children be ripped apart by shrapnel than to induce a gag reflex in their would-be murderer for 35 seconds?
UPDATE: Ramirez weighs in on the waterboarding debate:
In point of fact, as Kiriakou explains in the interview, no water even enters the person's nose during waterboarding.
RLC