The violent seizure by the Islamic State of Iraq and the Levant (Isis) of Ramadi, the capital of Anbar province — which stretches from near Baghdad to Iraq’s border with Jordan — is a huge blow to the Iraqi government and once again calls into question the country’s future as a unitary state. More immediately, it enables these Sunni millenarian jihadis, grafted onto the residual power networks of Saddam Hussein’s Ba’athist Iraq, to menace the western approaches to the capital and even threaten neighbouring Karbala province, home to one of Iraq’s two great Shia shrine cities.