In a great article I found in a link from Crooks and Liars, a US interrogator working in Iraq found that using the US Army field guide, not torturing people, and treating them respect works a lot better than beating on them:
Amid the chaos, four other Air Force criminal investigators and I joined an elite team of interrogators attempting to locate Zarqawi. What I soon discovered about our methods astonished me. The Army was still conducting interrogations according to the Guantanamo Bay model: Interrogators were nominally using the methods outlined in the U.S. Army Field Manual, the interrogators’ bible, but they were pushing in every way possible to bend the rules — and often break them. I don’t have to belabor the point; dozens of newspaper articles and books have been written about the misconduct that resulted. These interrogations were based on fear and control; they often resulted in torture and abuse.
I refused to participate in such practices, and a month later, I extended that prohibition to the team of interrogators I was assigned to lead. I taught the members of my unit a new methodology — one based on building rapport with suspects, showing cultural understanding and using good old-fashioned brainpower to tease out information. I personally conducted more than 300 interrogations, and I supervised more than 1,000. The methods my team used are not classified (they’re listed in the unclassified Field Manual), but the way we used them was, I like to think, unique. We got to know our enemies, we learned to negotiate with them, and we adapted criminal investigative techniques to our work (something that the Field Manual permits, under the concept of “ruses and trickery”). It worked. Our efforts started a chain of successes that ultimately led to Zarqawi.
It’s still amazing to me that anyone thinks that torture or “just smack them around a bit” ever works. In WWII, playing chess with captured Germans gave up more information than beatings ever did. Americans were tortured in Vietnam, and yet it did nothing to change their attitudes in the end (see John McCain).
Yet people still think that violating another human being’s civil rights will this time get the results you want. And every time, they are still wrong.