"I believe we are absolutely on the brink of failure. We are looking into the abyss," General Joseph Hoar, a former commander in chief of US central command, told the Senate foreign relations committee.
Larry Diamond, an analyst at the conservative Hoover Institution, said: "I think it's clear that the United States now faces a perilous situation in Iraq.
"We have failed to come anywhere near meeting the post-war expectations of Iraqis for security and post-war reconstruction.
"There is only one word for a situation in which you cannot win and you cannot withdraw - quagmire."
General Hoar was equally scathing about the calibre of the Bush administration.
"The policy people in both Washington and Baghdad," he said, "have demonstrated their inability to do a job on a day-to-day basis this past year."
(thanks to reader cab driver)