Sam Harris has an excellent article in his blog, "Why I’d Rather Not Speak About Torture", that includes an excerpt from his response to criticism of his idea of an ethical basis for torture under certain circumstances. Here is an excerpt from the excerpt:
My argument for the limited use of coercive interrogation (“torture” by another name) is essentially this: if you think it is ever justifiable to drop bombs in an attempt to kill a man like Osama bin Laden (and thereby risk killing and maiming innocent men, women, and children), you should think it may sometimes be justifiable to “ water-board” a man like Osama bin Laden (and risk abusing someone who just happens to look like Osama bin Laden). It seems to me that however one compares the practices of “water-boarding” high-level terrorists and dropping bombs, dropping bombs always comes out looking worse in ethical terms. And yet, most people tacitly accept the practice of modern warfare, while considering it taboo to even speak about the possibility of practicing torture.
I am with Sam Harris on this. My spectrum of circumstances under which torture would be ethically justified is actually wider than his. I think most people I know who are against torture are so because they have an ambiguous position on terrorism, and are absolutely against the war on terror, in particular, the war on Islamist terror.
Let me construct a different and narrower scenario. Suppose a known pedophilic and psychopathic killer has abducted a 3-year old girl. She is in imminent danger of being raped, and then murdered. We have in custody, a suspected accomplice who most likely knows his whereabouts. Would it be ethical to torture water-board, if necessary to get information that could save the little girl?