via Newsweek:

Two years ago I went to Iraq as an unabashed believer in toppling Saddam Hussein. I knew his regime well from previous visits; WMDs or no, ridding the world of Saddam would surely be for the best, and America's good intentions would carry the day. What went wrong? A lot, but the biggest turning point was the Abu Ghraib scandal. Since April 2004 the liberation of Iraq has become a desperate exercise in damage control. The abuse of prisoners at Abu Ghraib alienated a broad swath of the Iraqi public. On top of that, it didn't work. There is no evidence that all the mistreatment and humiliation saved a single American life or led to the capture of any major terrorist, despite claims by the military that the prison produced "actionable intelligence." read on