When I was still a member of what is probably best termed the British Jihadi Network, a series of semi-autonomous British Muslim terrorist groups linked by a single ideology, I remember how we used to laugh in celebration whenever people on TV proclaimed that the sole cause for Islamic acts of terror like 9/11, the Madrid bombings and 7/7 was Western foreign policy.

By blaming the government for our actions, those who pushed the 'Blair's bombs' line did our propaganda work for us. More important, they also helped to draw away any critical examination from the real engine of our violence: Islamic theology.

Friday's attempt to cause mass destruction in London with strategically placed car bombs is so reminiscent of other recent British Islamic extremist plots that it is likely to have been carried out by my former peers.

And as with previous terror attacks, people are again articulating the line that violence carried out by Muslims is all to do with foreign policy. For example, yesterday on Radio 4's Today programme, the mayor of London, Ken Livingstone, said: 'What all our intelligence shows about the opinions of disaffected young Muslims is the main driving force is not Afghanistan, it is mainly Iraq.'

He then refused to acknowledge the role of Islamist ideology in terrorism and said that the Muslim Brotherhood and those who give a religious mandate to suicide bombings in Palestine were genuinely representative of Islam.

I left the BJN in February 2006, but if I were still fighting for their cause, I'd be laughing once again. Mohammad Sidique Khan, the leader of the 7 July bombings, and I were both part of the BJN - I met him on two occasions - and though many British extremists are angered by the deaths of fellow Muslim across the world, what drove me and many of my peers to plot acts of extreme terror within Britain, our own homeland and abroad, was a sense that we were fighting for the creation of a revolutionary state that would eventually bring Islamic justice to the world.

How did this continuing violence come to be the means of promoting this (flawed) utopian goal? How do Islamic radicals justify such terror in the name of their religion? There isn't enough room to outline everything here, but the foundation of extremist reasoning rests upon a dualistic model of the world. Many Muslims may or may not agree with secularism but at the moment, formal Islamic theology, unlike Christian theology, does not allow for the separation of state and religion. There is no 'rendering unto Caesar' in Islamic theology because state and religion are considered to be one and the same. The centuries-old reasoning of Islamic jurists also extends to the world stage where the rules of interaction between Dar ul-Islam (the Land of Islam) and Dar ul-Kufr (the Land of Unbelief) have been set down to cover almost every matter of trade, peace and war.

What radicals and extremists do is to take these premises two steps further. Their first step has been to reason that since there is no Islamic state in existence, the whole world must be Dar ul-Kufr. Step two: since Islam must declare war on unbelief, they have declared war upon the whole world. Many of my former peers, myself included, were taught by Pakistani and British radical preachers that this reclassification of the globe as a Land of War (Dar ul-Harb) allows any Muslim to destroy the sanctity of the five rights that every human is granted under Islam: life, wealth, land, mind and belief. In Dar ul-Harb, anything goes, including the treachery and cowardice of attacking civilians.

This understanding of the global battlefield has been a source of friction for Muslims living in Britain. For decades, radicals have been exploiting these tensions between Islamic theology and the modern secular state for their benefit, typically by starting debate with the question: 'Are you British or Muslim?' But the main reason why radicals have managed to increase their following is because most Islamic institutions in Britain just don't want to talk about theology. They refuse to broach the difficult and often complex topic of violence within Islam and instead repeat the mantra that Islam is peace, focus on Islam as personal, and hope that all of this debate will go away.

This has left the territory of ideas open for radicals to claim as their own. I should know because, as a former extremist recruiter, every time mosque authorities banned us from their grounds, it felt like a moral and religious victory.

Outside Britain, there are those who try to reverse this two-step revisionism. A handful of scholars from the Middle East has tried to put radicalism back in the box by saying that the rules of war devised by Islamic jurists were always conceived with the existence of an Islamic state in mind, a state which would supposedly regulate jihad in a responsible Islamic fashion. In other words, individual Muslims don't have the authority to go around declaring global war in the name of Islam.

But there is a more fundamental reasoning that has struck me and a number of other people who have recently left radical Islamic networks as a far more potent argument because it involves stepping out of this dogmatic paradigm and recognising the reality of the world: Muslims don't actually live in the bipolar world of the Middle Ages any more.

The fact is that Muslims in Britain are citizens of this country. We are no longer migrants in a Land of Unbelief. For my generation, we were born here, raised here, schooled here, we work here and we'll stay here. But more than that, on a historically unprecedented scale, Muslims in Britain have been allowed to assert their religious identity through clothing, the construction of mosques, the building of cemeteries and equal rights in law.

However, it isn't enough for Muslims to say that because they feel at home in Britain they can simply ignore those passages of the Koran which instruct on killing unbelievers. By refusing to challenge centuries-old theological arguments, the tensions between Islamic theology and the modern world grow larger every day. It may be difficult to swallow but the reason why Abu Qatada - the Islamic scholar whom Palestinian militants recently called to be released in exchange for the kidnapped BBC journalist Alan Johnston - has a following is because he is extremely learned and his religious rulings are well argued. His opinions, though I now thoroughly disagree with them, have validity within the broad canon of Islam.

Since leaving the BJN, many Muslims have accused me of being a traitor. If I knew of any impending attack, then I would have no hesitation in going to the police, but I have not gone to the authorities, as some reports have suggested, and become an informer.

I believe that the issue of terrorism can be easily demystified if Muslims and non-Muslims start openly to discuss the ideas that fuel terrorism. (The Muslim community in Britain must slap itself awake from this state of denial and realise there is no shame in admitting the extremism within our families, communities and worldwide co-religionists.) However, demystification will not be achieved if the only bridges of engagement that are formed are between the BJN and the security services.

If our country is going to take on radicals and violent extremists, Muslim scholars must go back to the books and come forward with a refashioned set of rules and a revised understanding of the rights and responsibilities of Muslims whose homes and souls are firmly planted in what I'd like to term the Land of Co-existence. And when this new theological territory is opened up, Western Muslims will be able to liberate themselves from defunct models of the world, rewrite the rules of interaction and perhaps we will discover that the concept of killing in the name of Islam is no more than an anachronism.

Hassanbutt1@gmail.com