There is compelling anecdotal evidence of a surge in reversions to Islam since September 11, not just in Britain, but across Europe and America. One Dutch Islamic center claims a tenfold increase, while the New Muslims Project, based in Leicester and run by a former Irish Roman Catholic housewife, reports a "steady stream" of new reverts.
This fits a pattern set by recent history. Similar surges followed the outbreak of the Gulf War, the Bosnian conflict and the declaration of a fatwa against Salman Rushdie. Some of the newcomers doubtless do not share David Blunkett's enthusiasm for overt espousals of Britishness. Some of them - by all accounts a rapidly expanding minority - are white, more educated and more middle-class than the Home Secretary himself.
These are some of Islam's more surprising reverts. They have chosen their new creed over the world's other great religions having had the privilege of choice, often confounding their own and their families' prejudices in the process. They are highly articulate and tolerant to a degree. They're People Like Us, only they're not. They're Muslims. They pray five times a day, fast during Ramadan and hope to go to Makkah before they die. They answer their mobiles with "as-salaamu ‘alaykum".
They are people like Elizabeth L. (who asked for her name to be changed because she has not told her parents yet). Six months ago she - a graduate in political science, the daughter of affluent white British parents, an opponent of terrorism in all its forms - climbed Mount Sinai at night to watch the desert sunrise from its summit.
"It was the stillest, most peaceful place I've ever been," she says. "I could hear my feelings come up from within me, and in one surreal moment it all seemed to come together."
On Friday 4 January 2002, at 4.45pm, she went to Regent's Park Mosque in Central London and reverted to Islam. It wasn't hard. She witnessed by two Muslim men and nine other friends squeezed into the Imam's office, she pronounced, in Arabic learnt from a tape the night before, the words she will repeat like a mantra five times a day for the rest of her life: "There is no god but Allah and Muhammad is His Messenger." Afterwards there was a modest celebration at Al-Dar on the Edgware Road. Elizabeth and her well-wishers sipped mint tea.
Why has she done this? "I know it sounds clichéd, but Allah came knocking at my heart. That's really how it feels. In many ways it is beyond articulating, rather like falling in love."
It was, in other words, intensely personal. As she read the Quran and prepared for her reversion, the September attacks came and went and failed to derail her spiritual journey, despite their proven link to an Islamist terror network. In as far as they featured in her thinking, they even elicited some sympathy. All terrorism is cowardly, she says. "But I can see why people get fed up with the West. Capitalism is enormously oppressive."
Elizabeth is not a freak, and she is certainly not alone. There are many others, like Lucy Bushill-Matthews, a 30-year-old graduate of Newnham College, Cambridge, who flirted with Islam as a student in order to dismiss it, but found it "so simple and logical I couldn't push it away".
"When I went to Cambridge I joined the Christian and Islamic societies and all three political parties," she says. "I wanted to explore all the possibilities in order to dismiss them."
She thinks of herself as pragmatic and not all that spiritual, and as such she found Islam irresistible. "It made sense of all the world's faiths. It was a clear, simple way to believe in God." She claims that it has even helped her to land good jobs by marking her out as a free thinker. Her husband is a Muslim of English and Iranian descent whom she married after reverting.
Yahya, whose father is a pillar of the Anglo Establishment, feels that Islam "fits right into British tradition"; Yahya, too, chose Islam from the broadest possible religious gamut. He was raised in a high-profile London family that, because of his father's position, could not be seen to favour one faith over another. He then took a degree in comparative religion - the theological equivalent of a blind wine tasting - and Islam, quite simply, won.
"It's pure monotheism," he says. "It has a clear moral system and an intact tradition of religious scholarship. No scripture expresses its message of the oneness of God as clearly as the Quran. It also has a remarkably rich "mysticism", which may be what appeals to middle-class white Brits like me."
Yahya converted five years ago. Now 33, he is at Oxford writing a PhD on British Islam and is dismayed not just by last September's attacks, but also by the mauling he says his religion has suffered since in the media, even - or especially - at the hands of would-be sympathisers.
"It's very painful for all of us to be associated with such sickening barbarism (of the attacks)," he says. "That's not what we signed up for. And now we can't portray our religion in undiluted form. It's always mediated by someone else. It's incredibly frustrating to have Polly Toynbee trying to save you from yourself."
Joe Ahmed-Dobson, a son of the former Labour Health Minister Frank Dobson, believes that Islam transformed his spiritual life - and helped him to get a first at university. Now, he works on inner city regeneration, finds spiritual satisfaction in Islam's "constant impetus to do the right thing", and credits his first-class degree to the structure his faith has brought to his life.
Matthew Wilkinson made headlines when he converted and changed his name to Tariq in 1993; he was a former Eton head boy. He and Nicholas Brandt, another Etonian and the son of an investment banker, swapped their destinies as scions of the Establishment for a Slough semi shared with four other Muslims.
Lord Birt's son, Jonathan, forsook a fast track into the ranks of the great and the good by converting in 1997 and starting a PhD on British Islam. So did a son and a daughter of Lord Justice Scott, the scourge of Tory sleaze and the chairman of the Arms to Iraq inquiry.
All those reverts rejected Christianity on intellectual grounds. They had Why grapple with mental puzzles such as the Holy Trinity and Original Sin, they asked, when the alternative, asserting neither, proved to them so much more satisfying? It was this clarity that won over them.