From an article in Newsweek (thanks to Adina):
But a NEWSWEEK investigation shows that, as a means of pre-empting a repeat of 9/11, Bush, along with Defense Secretary Rumsfeld and Attorney General John Ashcroft, signed off on a secret system of detention and interrogation that opened the door to such methods. It was an approach that they adopted to sidestep the historical safeguards of the Geneva Conventions, which protect the rights of detainees and prisoners of war. In doing so, they overrode the objections of Secretary of State Colin Powell and America's top military lawyers—and they left underlings to sweat the details of what actually happened to prisoners in these lawless places. While no one deliberately authorized outright torture, these techniques entailed a systematic softening up of prisoners through isolation, privations, insults, threats and humiliation—methods that the Red Cross concluded were "tantamount to torture."
The Bush administration created a bold legal framework to justify this
system of interrogation, according to internal government memos obtained
by NEWSWEEK. What started as a carefully thought-out, if aggressive,
policy of interrogation in a covert war—designed mainly for use by a
handful of CIA professionals—evolved into ever-more ungoverned tactics
that ended up in the hands of untrained MPs in a big, hot war.
Originally, Geneva Conventions protections were stripped only from Qaeda
and Taliban prisoners. But later Rumsfeld himself, impressed by the
success of techniques used against Qaeda suspects at Guantanamo Bay,
seemingly set in motion a process that led to their use in Iraq, even
though that war was supposed to have been governed by the Geneva
Conventions. Ultimately, reservist MPs, like those at Abu Ghraib, were
drawn into a system in which fear and humiliation were used to break
prisoners' resistance to interrogation.