There is. It's that constraining someone to give you information by violent means gives you false information.
Quite. What you need for torture to "work" is an infallible lie detector: You need to identify the guilty with some certainty AND know when they're telling you the truth or not. And if you're already *that* darn good, what do you need with torture?
Knowing both those things is rare enough with individuals. To make torture *policy* would be laughable if it wasn't so abhorrent.
F'r Cr'sts sake! Human intel. is spotty enough when the source *likes* you. Torture isn't just ineffective, it's counterproductive: It ties up manpower and generates more false leads than good ones.
Ok... so... yes, if you had unlimited manpower and/or unlimited time torture could work: You just torture everybody and check out everything they say. OTOH, with with unlimited manpower and/or time you almost certainly don't need torture at all.
And then there's still the PR effects to consider. And what it's likely doing to the effectiveness and morale of torturing organization. "Counterproductive" is an understatement.
Torture is for those who place punishment above justice, activity ahead of effectiveness, and feeling strong over being safe.
The better technique is to get people to give you good information. I don't see how you could do this and yet still use torture. It's kind of a contradiction.
Yup. The FBI has pretty much demonstrated this.
There are some unkind mind-games you can play with prisoners that can be effective. I wouldn't call them torture - they don't involve coercion, physical abuse (or drugs, deprivation, etc.) and play out in a few days or less. But I'd say technically they are torture, since I would characterize them as "mistreatment". The infamous slippery slope is also a concern.