Report: Bush, Cheney, Rumsfeld kept detainees in Gitmo whom they knew to be innocent, for political advantage

Did George Bush and Donald Rumsfeld keep prisoners in Guantánamo whom they knew were innocent, for PR reasons? "Colonel Wilkerson, who was General Powell's chief of staff when he ran the State Department […] claimed that former Vice-President [Cheney] and Defense Secretary [Rumsfeld] knew that the majority of the initial 742 detainees sent to Guantánamo in 2002 were innocent but believed that it was 'politically impossible to release them'." (via Nicholas Kristof)