From three years ago, but still quite relevant: "'Manchurian Candidate' Was No Mere Fiction."

The prisoners had not been drugged and brainwashed with secret, irresistible techniques. They were never under absolute psychological control of their captors. No secret triggers put them into a trance, such as the famous Queen of Diamonds in The Manchurian Candidate. In short, these troops had not been “brainwashed.” Instead they had been subjected to the type of comprehensive indoctrination routinely employed by Soviet and Chinese officials against their own dissidents, along with German and Japanese POWs from World War II. The methods included isolation; sleep deprivation; compulsory ideological classes; threats; public- and self-criticism; endless “confessions;” exploitation of anger over U.S. racial discrimination; destruction of the chain of command; sophisticated psychological pressure; bribery and blackmail.