A journalist and author who spent four years within a radical Islamist organisation has shared his experience with listeners.
Shiraz Maher, author of Salafi-Jihadism: The History of an Idea was born in the UK in 1981, but his family moved to Saudi Arabia while he was an infant. In 1995, he moved back to Britain. He joined Hizb ut-Tahrir, a radical Islamist group, in 2001.
He explained their theology and principal activities to listeners.
"They want to establish a caliphate," Maher told Sam Delaney. "The idea was to have this global, super Islamic state which would be a utopia for all Muslims.
"The way it operates is principally as a political movement. It has associations with violent movements, but no involvement with violence itself. It was kind of like the relationship between Sinn Fein and the IRA. I was involved in the political wing, the political campaigning and moral imperatives for the activities carried out by other people."
The journalist explained why he joined the group, and how 9/11 tipped the scales for him.
"For me, it was about an issue of identity. Where do I fit in, am I British, do I belong here, can I reconcile being a Muslim with being British?
"In the immediate aftermath of 9/11, there was a sense of all these different questions as well as a polarisation. Bin Laden talked about it, saying you were in two camps, George Bush said 'you're either with us or against us'. Divisive language forced people to make a call, and I chose to go the other way.
"It's important you have empathy for the individual caught up in the attacks, but on the political level, you're saying 'this happens to us [the Muslim world] all the time', the feeling of persecution, the narrative of victimhood, the sense of 'an eye for an eye'.
"Because I grew up in the Middle East, there was a sense of conspiracy it [the United States] was weighted against us. This [September 11th] was seen as payback, and this, in essence, is how it was explained away and rationalised."
Maher was a member of Hizb ut-Tahrir for four years, but eventually, he began to grow disillusioned with the group's cause. His eventual exit on 7 July 2005, the same day as the bombings on the London Underground, was met with "a lot of disgust and anger".
"What traditionally happens within radical groups is they want you to just read their own or radical literature. You're only socialising with other radicals and extremists, and I'd not only given up my non-Muslim friends but also other Muslims who weren't as devoted.
"But I'd started to read much more widely, to look at Islam much more broadly. For a period of seven to nine months prior to 7/7, I'd already started to have doubts, and once I challenged the fundamental basis upon which their idea had been constructed, I realised I couldn't be a part of it."
Maher is now firmly opposed to jihadism, and works as a Senior Research Fellow for the International Center for the Study of Radicalisation at King's College, London. His personal experience makes him the top expert in the field.
"I've interviewed more than 100 people from this country who have gone off to fight with ISIS and various other groups in Syria and Iraq. I see in them the kind of person I was when I had been radicalised.
"It's the same sense of 'we're on the cusp of history', something dramatic is happening, the world is being divided into two separate camps, it's all the same things I see in these young people today."
His book, Salafi-Jihadism: The History of an Idea, explores the idea of jihad, and the mentalities which surround radicalised individuals.
"It's looking at how the idea works. When we look at it, the violence they are committing is grotesque, it's horrific. It defies logic for us, but for them, it's a perfectly rational, reasonable, well-thought out idea.
"What I wanted to do was to take readers into the idea, to show them how a man sitting on the Tube next to them becomes Jihadi John the next day. What is this idea, and what has happened to this idea to make people embrace the ideology?
"What I definitely don't want people to take away as their impression of this is that everyone who goes is a considered ideologue who has really understood it. In fact, what I have discovered when speaking to them is they don't have a particularly sophisticated or developed knowledge of Islamic theology, or the ideas I'm discussing in the book."
Maher highlighted how the creation of divisions between different groups is never a good influence on society.
"The sense of misunderstanding and polarisation is bad for our society as a whole. Britain is, to my mind, one of the fairest and most progressive countries in the western world.
"There is probably nowhere better to be a Muslim than in the UK. There is definitely a crisis going on with Muslims and their identity, as well as the English working classes.
"We need to all be looking at all sides of our society."