Charlie Stross puts forth one possible explenation for why the bush administration does what it does:
Rumsfeld is a corporate manager. Bush is, too. So is Cheney. It all seems to be of a piece with the willingness to use any means to get results, however evil, the obsession with meeting goals regardless of colateral damage, the determination to spin criticism as subversion or treason, and so on. They think they’re running America, Inc., may the devil take the hind-most, and society can look after itself. In this kind of climate, is it any surprise that low-level employees try to shape up to the perceived expectations of their masters and deliver results by any means necessary, however dehumanizing or monstrous? And is it any surprise that they refuse to be held to account by anyone except their shareholders? (And I’m not talking about Congress here.)