Here’s a taste of the Bush administration’s legal rationale, exemplified in one excerpt from the 2002 OLC memo written by Assistant Attorney General Jay Bybee, about the interrogation of Abu Zubaydah, a high-ranking al Qaeda member:
Sleep deprivation may be used. You have indicated that your purpose in using this technique is to reduce the individual’s ability to think on his feet and, through the discomfort associated with lack of sleep, to motivate him to cooperate. The effect of such sleep deprivation will generally remit after one or two nights of uninterrupted sleep. You have informed us that your research has revealed that, in rare instances, some individuals who are already predisposed to psychological problems may experience abnormal reactions to sleep deprivation. Even in those cases, however, reactions abate after the individual is permitted to sleep. Moreover, personnel with medical training are available to and will intervene in the unlikely event of an abnormal reaction. You have orally informed us that you would not deprive Zubaydah of sleep for more than eleven days at a time and that you have previously kept him awake for 72 hours, from which no mental or physical harm resulted. (our itals)
If you have time, comb through the memos yourselves (they’re here) and let us know what else you find.