Book excerpt: From Europe's burgeoning terrorist underground, to the training camps of Afghanistan, to the radical mosques of London, this is a unique and chilling insider's story of the rise of Al Qaeda and the intelligence services that struggle to contain it. Between 1994 and 2000, Omar Nasiri worked as a secret agent for Europe's top foreign intelligence services -- including France's DGSE (Direction Gérale de la Séritéxtéeure), and Britain's MI5 and MI6. From the netherworld of Islamist cells in Belgium, to the training camps of Afghanistan, to the radical mosques of London, he risked his life to defeat the emerging global network that the West would come to know as Al Qaeda. Now, for the first time, Nasiri shares the story of his life -- a life balanced precariously between the world of Islamic jihadists and the spies who pursue them. As an Arab and a Muslim, he was able to infiltrate the rigidly controlled Afghan training camps, where he encountered men who would later be known as the most-wanted terrorists on earth, going so far as to form a sleeper cell in Europe with Al Qaeda's top recruiter in Pakistan and London's radical cleric Abu Qatada. A detailed portrait of a complex man who fought on both sides,Inside the Jihad is a terrifying, suspenseful look at an organization that continues to be a global threat.