Sen Carl Levin (D. Mich) is the chairman of the Senate Armed Services Committee. His opening statement at the June 17, 2008 hearing describes the history of the use of interrogation techniques by the US DoD. It's quite amazing.
One particularly striking feature is how bureaucratic it all was. The proposed techniques were passed up and down a number of chains of command. It's a good thing that so many people were involved in reviewing the policies. Many had the courage to object.
The account makes it clear, though, how far the military moved away from treating people like people. It was only at the end of Levin's statement when he quoted a statement by Gen. Petraeus that there was any mention at all of treating people humanely. Most of the discussion was about legal issues, as if the concern was not whether it's right to inflict pain but only whether it's legal. There was no discussion at all about the subjective experience of the prisoners, no attempt to understand what it must feel like to be treated this way, only whether the techniques would be legal and effective. It was like listening to two guards discussing the relative merits of different makes of thumb screws. Should we buy Brand A because it's cheaper or Brand B because it's more sturdy? A study is needed to assess the comparative ROIs and make the right purchase decision.