How Al-Qaeda's mastermind turned his back on terror - Part one. By Lawrence Wrigh

In May 2007, a fax arrived at the London office of the Arabic newspaper Asharq al-Awsat from a shadowy figure in the radical Islamist movement who went by many names. Born Sayyid Imam al-Sharif, he was the former leader of the Egyptian terrorist group al-Jihad, and known to those in the underground mainly as Dr Fadl. Members of al-Jihad became part of the original core of al-Qaeda; among them was Ayman al-Zawahiri, Osama bin Laden's chief lieutenant. Fadl was one of the first members of al-Qaeda's top council. Twenty years ago, he wrote two of the most important books in modern Islamist discourse; al-Qaeda used them to indoctrinate recruits and justify killing. Now Fadl was announcing a new book, rejecting al-Qaeda's violence. 'We are prohibited from committing aggression, even if the enemies of Islam do that,' Fadl wrote in his fax, which was sent from Tora Prison, in Egypt.

Fadl's fax confirmed rumours that imprisoned leaders of al-Jihad were part of a trend in which former terrorists renounced violence. His defection posed a terrible threat to the radical Islamists, because he directly challenged their authority. 'There is a form of obedience that is greater than the obedience accorded to any leader, namely, obedience to God and His Messenger,' Fadl wrote, claiming thathundreds of Egyptian jihadists from various factions had endorsed his position.

Two months after Fadl's fax appeared, Ayman al-Zawahiri issued a video on behalf of al-Qaeda. 'Do they now have fax machines in Egyptian jail cells?' he asked. 'I wonder if they're connected to the same line as the electric-shock machines.' This sarcastic dismissal was perhaps intended to dampen anxiety about Fadl's manifesto - which was to be published serially, in newspapers in Egypt and Kuwait - among al-Qaeda insiders. Fadl's previous work, after all, had laid the intellectual foundation for al-Qaeda's murderous acts. On a recent trip to Cairo, I met Gamal Sultan, an Islamist writer and a publisher. He said of Fadl, 'Nobody can challenge the legitimacy of this person. His writings could have far-reaching effects not only in Egypt but on leaders outside it.' Usama Ayub, a former member of Egypt's Islamist community, who is now the director of the Islamic Centre in Munster, Germany, told me, 'A lot of people base their work on Fadl's writings, so he's very important. When Dr Fadl speaks, everyone should listen.'

Although the debate between Fadl and Zawahiri was esoteric and bitterly personal, its ramifications for the west were potentially enormous. Other Islamist organisations had gone through violent phases before deciding such actions led to a dead end. Was this happening to al-Jihad? Could it happen even to al-Qaeda?