The techniques used to break Padilla have been standard operating procedure at Guantánamo Bay since the first prisoners arrived five years ago.
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Many have suffered the same symptoms as Padilla. According to James Yee, former Army Muslim chaplain at Guantánamo, there is an entire section of the prison called Delta Block for detainees who have been reduced to a delusional state. "They would respond to me in a childlike voice, talking complete nonsense. Many of them would loudly sing childish songs, repeating the song over and over." All of Delta Block was on twenty-four-hour suicide watch.
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These standard mind-breaking techniques have never faced scrutiny in a US court because the prisoners in the jails are foreigners and have been stripped of the right of habeas corpus--a denial that, scandalously, was just upheld by a federal appeals court in Washington, DC. There is only one reason Padilla's case is different: He is a US citizen... He is the only victim of the post-9/11 legal netherworld to face an ordinary US trial.

Now that Padilla's mental state is the central issue in the case, the government prosecutors have a problem. The CIA and the military have known since the early 1960s that extreme sensory deprivation and sensory overload cause personality disintegration--that's the whole point. "The deprivation of stimuli induces regression by depriving the subject's mind of contact with an outer world and thus forcing it in upon itself. At the same time, the calculated provision of stimuli during interrogation tends to make the regressed subject view the interrogator as a father-figure." That comes from Kubark Counterintelligence Interrogation, a 1963 declassified CIA manual for interrogating "resistant sources."