Agent Storm: My Life Inside Al Qaeda by Morten Storm with Tim Lister and Paul Cruickshank, book review

Morten Storm celebrated his 13th birthday by attempting an armed robbery. His life spiralled into "a cycle of drugs, gratuitous violence and hardcore partying". Two spells behind bars followed by all the soft skills of the Danish social system had no effect on Storm. Then one day he stumbled across a book about the Prophet Muhammad in his local library.

Storm's conversion was swift and radical. Eventually, he travelled to Yemen to study Islam and learn Arabic. He named his first child after Osama bin Laden and married a Yemeni woman. Storm's journey is timely and familiar: the appeal of extremism to disaffected youth. More than 2,000 European militants have travelled to fight in Syria. The book's most surprising revelation is the readiness and trust with which Westerners are accepted as jihadis. The fact that double agents may be planted among those Westerners doesn't seem a matter of concern.

At first, Storm, with his red hair and heavyweight boxer's build, was a curiosity at the Dammaj madrassa. Later, his militancy and enthusiasm marked him as a star convert. He was soon befriended by the radical elite, including Anwar al-Awlaki, regarded by CIA as "the future of al-Qaeda". No surprise that Storm was soon on the radar of more than one Western intelligence agency.

Storm's rejection of Islam was even more sudden than his conversion. In 2007, with his heart set on jihad, he bought a one-way ticket to Mogadishu. At the last minute, his trip was cancelled. Storm recounts: "Dejection soon became anger, and anger began to ask some difficult questions." Storm maintains that his break with Islam was the discovery of "Contradictions in the Koran". But a Danish social worker might have cited a need for instant gratification. He had waited 10 years for jihad and he wasn't going to wait a moment longer. The next day he was eating a bacon sandwich and drinking Carlsberg beer with officers from PET, the Danish security service.

Storm's most important mission was to plant a tracking device near Awlaki, now number two on the US kill list. Storm had received $250,000 for arranging Awlaki's marriage to a Croatian bride who would unwittingly carry the device hidden in a suitcase. CIA promised a further $5m for Awlaki's death, but later claimed that the Hellfire drone which finally killed Awlaki had not been guided by the suitcase sensor. That, and other broken promises, provoked Storm to go public about his role as an agent. The allegations have proved explosive in Denmark where collaborating with state-sponsored assassination is illegal. Storm's claims also paint PET as a sleazy organisation who schedule meetings in Bangkok and Lisbon for bouts of boozy sex tourism at taxpayers' expense.

His betrayals have left his future and personal safety bleak. The intelligence agencies have met his allegations with a "wall of silence". Storm claims to have turned down a gagging deal swapping silence for witness protection programme relocation.

The book's ghosts, Tim Lister and Paul Cruickshank, are CNN journalists who specialise in international security and terrorism. They begin with an "Authors' Note" acknowledging that Storm's account will face "scrutiny". They then cite an "extraordinary amount of audiovisual evidence and records of electronic communications" that "both corroborate his story and enrich his account". The rest is up to the reader.

Edward Wilson's latest novel is 'The Whitehall Mandarin'