In a famous bon mot, Irving Kristol – often described as the “godfather of neo-conservatism” – joked that a neo-conservative is “a liberal who has been mugged by reality”. But the neo-cons have just been mugged by reality once again. Only this time the mugging has taken place on the streets of Baghdad, rather than in the housing projects of the US.

There is still hope some good could finally emerge from the horrifying violence engulfing much of Iraq. But even if it avoids a civil war or a new dictatorship, the central plank of the neo-conservative world view has been splintered by Iraq. Who now believes that US-led military intervention is an appropriate way of spreading democracy around the world? As that idea dies a grisly death in Iraq, the struggle is on in Washington to define a new basis for US foreign policy.