The U.N. Convention Against Torture, to which the U.S. is a signatory, defines torture as the infliction of "severe pain." The U.N. Convention is implemented in U.S. law (18 U.S.C. 2340). Yoo's legal task was to find legal grounds to define "severe" in such a diminished way as to allow the Bush administration to torture without fear of punishment. This was no easy task: There simply is nothing on the books to support such a redefinition. But when there's a war on terror to be fought, creative minds find a way.

"The statute Yoo cited, 42 U.S.C. 1395, regulates insurance benefits under the "Medicare and Choice" plan. It defines an emergency medical condition as one "manifesting itself by acute symptoms of sufficient severity (including severe pain) that a prudent layman" could reasonably expect that without immediate medical treatment, the individual displaying those symptoms would be at serious risk of losing their health, suffering serious impairment to bodily functions, or suffering serious dysfunction of any bodily organ or part. From this bureaucratic definition of "emergency medical condition," Yoo magically derived a new, torture-friendly definition of "severe pain."

"Although these statutes address a substantially different subject from section 2340," Yoo blandly notes in a world-class understatement, "they are nonetheless helpful for understanding what constitutes severe physical pain. They treat severe pain as an indicator of ailments that are likely to result in permanent and serious physical damage in the absence of immediate medical treatment. Such damage must rise to the level of death, organ failure, or the permanent impairment of a significant body function. These statutes suggest that to constitute torture 'severe pain' must rise to a similarly high level -- the level that would ordinarily be associated with a physical condition or injury sufficiently serious that it would result in death, organ failure, or serious impairment of body functions."