Andrew Sullivan posts the following reader comment:

Bush's supporters will inevitably use the fact that virtually all of us can think of some emergency exceptions to an absolute "no torture" rule. ("Ace of Spades" has been yelling for some time about the need to enable it to expose plots that "endanger thousands of lives", and specifically cites the London airliner bombing plot in that regard.)  This argument has real teeth in it, and the only way to counter it is to point out that – in any case where torture really was necessary to stop such a plot – there is no way in hell that the torturer would ever actually go to jail for it; the jury would certainly not convict him, even if the prosecutor indicted him.  (To say nothing of the President's power to pardon.) It would fall into the category of "justifiable assault."

This is an argument that I've heard repeated among those who believe all forms of torture or "alternative" interrogation techniques should be banned, but it is deeply flawed. On a moral level, if you believe that torture is wrong in all cases, you shouldn't be willing to make exceptions after the fact. This would be like arguing against warrantless searches of people's homes, but saying that if a cop breaks into somebody's house without a warrant, evidence gathered can be admissible as long as it's crucial enough. I don't know how you give mixed-signals to CIA agents that all forms of torture are illegal, but (wink, wink) if you torture someone and your hunch is proven correct, you won't be prosecuted. Furthermore, it would seem to create a moral hazard that could prompt CIA agents to torture someone more aggressively. If a CIA agent tortures a terrorist suspect believed to have information about an imminent attack, but the terrorist doesn't talk, the agent is in legal trouble for torturing somebody without being able to expose a terrorist plot. That may prompt the agent to torture that detainee more aggressively, thinking that the only way for him to avoid prosecution is to get the detainee to talk, by any means necessary.

People who make this argument are trying to have it both ways. Deep down, they know that in certain cases, torture may save lives, so they want to leave the door open to that, but at the same time, they want to claim the moral high ground by saying that they support an outright ban on torture for humanitarian reasons.   

I'm sure that many (if not most) people who oppose an outright ban on all torture are speaking out of genuine ethical concern. I understand that in this war against an enemy of unspeakable evil, each one of us will have to decide where we would draw the line in responding to the threat. And I have deeply considered arguments about the societal implications of condoning torture, or "aggressive interrogation," or whatever else you wish to call it. But personally, I have absolutely zero moral qualms about waterboarding somebody like Khalid Sheikh Mohamed if it could yield information that could save lives, and I'm under no illusions that waterboarding is a pleasant experience. I believe the debate over torture should be about how to craft a law that would allow high level terrorists to be aggressively interrogated in limited circumstances while making sure that the practice doesn't become widespread. This is a challenge, no doubt, but I think there are ways to accomplish this (Alan Dershowitz's idea of torture warrants would be one possible way to add oversight to the process).   

This debate gets to the heart of why I consider terrorism such a grave threat, and why I perceive it as the perfect tool to fight a civilized society that seeks to preserve life and protect human rights. No matter how severe the threat of Nazism was, at least once World War II got rolling, there was little debate among civilized people over what we had to do to fight it. The elusive nature of terrorism, however, causes division as we struggle with the moral and logistical implications of responding to it.