The lawyers identify three concepts that would permit American personnel to commit crimes in the course of interrogation.
http://www.capitolhillblue.com/artman/publish/printer_4652.shtml

One is that President Bush, as commander in chief of the military, has complete authority to make war, and interrogating prisoners falls within that scope. It likens congressional or judicial review of interrogation procedures to Congress, or a court, interfering with the planning of a battle.

"In order to respect the President's inherent constitutional authority to manage a military campaign, ... (the prohibition against torture) must be construed as inapplicable to interrogations undertaken pursuant to his Commander-in-Chief authority," the paper says.

Another, termed necessity, is that hurting or even killing one person to save two lives is justified. The third concept, self-defense, says the harsh interrogation of a prisoner believed to have information on an imminent terrorist attack is the same as shooting someone pointing a gun at you. Law professor O'Connell called that an "absurd" leap, saying the situations are not legally equivalent.