It was supposed to be a happy farewell, a visit that would bring George W. Bush to a less troubled, and a less bloody Iraq, and help to burnish his legacy. But when he stood in Baghdad next to prime minister Nouri al-Maliki, the US president who had toppled Saddam Hussein was greeted with a damning insult.

Instead of celebrating the success of a military surge which has curbed sectarian violence, and the signing of a security agreement which is due to bring home the more than 100,000 US troops, Mr Bush was forced to dodge shoes hurled at him by an Iraqi journalist.