So we are to have a torture debate again. Let's try to establish a base line of facts, shall we? Otherwise it will just be a moral posturing exercise.
Torture works. if you know something, you will talk about it under torture.
Extreme measures of interrogation that don't reach the level of torture will work, too.
Heck, a pack of cigarettes and a nice meal with a quiet chat might do the job.
How much time do you have?
But keep in mind that just because something is extremely unpleasant and scary doesn't mean it is torture. I don't think waterboarding--which does not leave lasting physical damage (unlike Senator McCain who can't use one arm to this day from his days in the Hanoi Hilton)--is torture. We do it to our own military people to give them an idea of what to expect from enemies if captured by them.
We are also free as a society to ban the use of extreme measures like waterboarding without having to declare it torture. We could ban tickling if we want to. Or ban giving prisoners cigarettes as a health matter.
In the days after 9/11, we did not torture. We used waterboarding and other extreme measures. And we used them sparingly. And we used them because 9/11 was a surprise attack and we quickly discovered that we didn't even know what we didn't know. We were desperate to prevent another attack on that scale.
Times have changed. So we don't have the same motivation to use waterboarding or other extreme measures now, even if we allow them. We're better at other means of intelligence and we have more information in general. Our level of not knowing what we don't know is much lower.
So why do people say that torture doesn't work? Because routine torture of people on a large scale to get information that you have no way of cross-checking does not work. This was a lesson of France's campaign against Algeria's independence movement. Sweeping up people and torturing them gave a flood of bad information, with no real way to confirm even good information if they happened to nab a real enemy, and simply turned more of the people against the French.
As I said, torture will get you talking. It you know something, you will talk about it. If you mislead, and you are told by the torturers that they know how you are misleading, you will eventually talk a little more accurately about what you know.
But if you know nothing, you will talk--about anything that you think will get the torture to stop. That is what people mean when they say "torture doesn't work."
I'd have thought people skilled in nuance would do a better job of understanding stuff like this.
And here's an interesting post on why Secretary of Defense Mattis might have said torture doesn't work.
So have that debate now about what we are willing to do to get information about people trying to kill us in large numbers.
UPDATE: Eric at Learning Curve suggests this as a useful site on the issue.