I know Joe Conason's been cited elsewhere; but here is a cite of Conason's article by Atrios:
How did the "permissive environment" that encouraged rampant criminality and cruelty arise at Abu Ghraib? According to the JAG senior officers who spoke with Horton, Pentagon civilian officials removed safeguards that were designed to prevent such abuses. At a detention facility like Abu Ghraib, those safeguards would include the routine observation of interrogations from behind a two-way mirror by a JAG officer, who would be empowered to stop any misconduct.
The JAG officers told Horton that those protective policies were discontinued in Iraq and Afghanistan. They said that interrogations were routinely conducted without JAG oversight -- and, worse, that private contractors were being allowed unprecedented participation in the interrogation process. Moreover, the contractors who participated in the interrogation of Iraqi prisoners were operating in a legal twilight zone, says Horton. More - there's more at Salon too.
These practices were known about and encouraged by the Bush administration. It's time for the American people to demand bush's resignation or impeachment. This is a disgrace to the US - bush is responsible.