A former jihadist who became an Al-Qaeda double agent says Muslims must do more to tackle extremism in their midst and that stopping lone wolf attacks is near-impossible.
Morten Storm has seen deep inside the conflict between jihadists and Western intelligence services, having served both.
He was a Danish petty criminal who converted to Islam in the 1990s and became embroiled in the global jihadist network, before abruptly losing his faith and turning against his former friends.
Storm, 39, has emerged from his experiences with a strong conviction that Muslim communities need to be at the forefront of efforts to tackle radical Islam.
"(European) governments live in denial. It's like an alcoholic denying they have a drinking problem. We have a problem with this religion that we need to address honestly," he said.
He was speaking in Paris, where his book "Agent Storm: My Life Inside Al-Qaeda and the CIA" is about to be released in French.
He said claims by Western governments that attacks such as those in Paris and Copenhagen this year had nothing to do with Islam "made a mockery" of those who were fighting for a more tolerant version of the religion.
"The silence of the majority of Muslims who are not doing anything about ISIS could lead to a war throughout the Middle East," said Storm, referring to the Islamic State group based in Syria and Iraq.
His own years of deception have also highlighted the challenge of identifying radicalised individuals who act alone.
"It's difficult to prevent lone wolf attacks. You have to understand what's inside the mind of a person: one day from being a person going to the mosque every day, to one day changing within himself and stabbing someone or running them down with a car -- it's very difficult if not impossible for the intelligence services to stop that."
Storm's own decision to abandon radical Islam was triggered after he was unable to join the fight alongside Shebab jihadists in Somalia, which caused him to question God's will.
"It was like being part of the World Cup team and being pulled out at the last minute," he said.
The disappointment, he said, led him finally to challenge the extremist version of Islam he had adopted after serving time in prison for assault in 1997.
After months of soul-searching, he privately renounced Islam and became a spy, helping the CIA, Britain's MI6 and Denmark's PET agencies locate and kill some of the world's top jihadists.
He claims his efforts were crucial in killing Anwar al-Awlaki, an American citizen and top Al-Qaeda leader in Yemen, who was blown up by a US drone in 2011.
Storm helped locate a wife for Awlaki, a 32-year-old blond Croatian who had converted to Islam and was looking for a jihadist to marry.
He maintained his contact with Awlaki, and claims he managed to get a USB stick to him that allowed the United States to pinpoint its drone strike in September 2011.
But his relationship with the intelligence services soon soured.
The British and the Danes did not want to be part of assassination plots, and Storm claims the CIA refused to cough up the $5 million they had promised for helping him kill Awlaki.
He says the CIA even tried to have him killed -- "perhaps to tie up loose ends" -- at which point he decided to go public for his own safety.
"The agents do not have rights, we are disposable," he said.
He keeps his harshest criticism for the Danish PET, claiming a friend who died in Syria in 2013 was a double agent, but his family have never been told.
"This discourages other agents. If you can't trust your government, who can you trust?" he said.
Two CNN terrorism analysts, Paul Cruickshank and Tim Lister, helped Storm write the book and confirmed some of the details in his story, although the spy agencies have refused to comment.
In an interview on Tuesday, Cruickshank said a key lesson from Storm's personal history was that jihadist violence was often based on religious conviction, not just political or economic grievances.
"It's going to be the Muslim communities that are going to have to challenge this ideology," he said.
"There are very, very courageous Muslim community leaders across Europe who are standing up, risking their lives to speak out against this and too seldom are they fully backed by Western governments."