As they fled Afghanistan after 9/11 some of bin Laden’s followers wondered whether the attacks on the US had been a mistake. Among them was one of al-Qaida’s most acerbic writers, Abu Musab al-Suri. In public he backed bin Laden: privately he described him as an obstinate egotist. And he was scathing about the consequences of 9/11: ‘The outcome, as I see it, was to put a catastrophic end to the jihadi current which started in the early 1960s.’