Christopher Hitchens in Vanity Fair:
Here is the most chilling way I can find of stating the matter. Until recently, “waterboarding” was something that Americans did to other Americans. It was inflicted, and endured, by those members of the Special Forces who underwent the advanced form of training known as sere (Survival, Evasion, Resistance, Escape). In these harsh exercises, brave men and women were introduced to the sorts of barbarism that they might expect to meet at the hands of a lawless foe who disregarded the Geneva Conventions. But it was something that Americans were being trained to resist, not to inflict.
More here.