One of the writers doing the best work on this topic has been Scott Horton. His latest is here: http://www.harpers.org/archive/2008/03/hbc-90002745
If anyone in this administration is ever held to account for their war crimes (and let's be 100% clear here, authorizing torture is a war crime. We established that more than 50 years ago.) it will be because of Horton and a few other individuals who have tried to uphold the honor of the United States.