When I last heard Asma al-Assad speaking in public, at a conference in Damascus six months ago, it was like being back in the early days of Tony Blair's Britain. In a clear Home Counties accent, the London-born first lady of Syria used slogans such as "active citizenship" to explain to Arab English-language students: "You must all have a stake in your country - a chance to make it what you want."

In Syria, the sight of the glamorous 36-year-old meeting her people in souks and squares perpetuated the comparison with media-savvy Blairism. Beneath the designer labels - Chanel sunglasses and Christian Louboutin heels - there was, the masses were told, a woman who could articulate the need for popular reform with a steely intelligence.

But now, the "Asma project" has been abandoned. The lethal force that her husband, Bashar al-Assad, has used against Syria's pro-democracy movement has rendered all the soundbites redundant, and there are rumours that Asma has fled to the UK with her three young children. Her parents, the consultant cardiologist Fawaz Akhras and his retired diplomat wife, Sahar Otri (both Sunni Muslims who left Syria in the 1950s), live in Acton, west London.

Asma was known as "Emma" when growing up, and first met Bashar, from the minority Alawite sect, on a family holiday in Syria. In 1992, Bashar, second son of the dictator Hafez al-Assad, began a postgraduate degree in ophthalmology in London but was summoned home after his elder brother, Basil, died in a car crash in 1994. As the new heir to the presidency, he courted his overseas girlfriend in secret. They eventually married in December 2000.

Wherever she may be, Asma's "disappearance" says everything about the increasingly desperate situation in Syria. What are the chances that some of the thousands who have been killed, wounded or imprisoned during the current unrest were involved in Massar, the organisation that she founded in 2005 to involve young people in "active citizenship"?

Laughable as it now sounds, the first lady said then that young Syrians should be turning their attention towards "empowerment in civil society". Few of them might have benefited from the kind of privileged education that Asma enjoyed in England - she attended the Queen's College private school for girls on Harley Street and took a First in computer science at King's College London. But, she argued, they could all be "usefully involved" and have an "international perspective". Asma, who worked for Deutsche Bank and JPMorgan before she got married, was also keen to tell the Syrian people that IT skills could be translated into untold wealth in the global economy.

What she forgot to mention was that young people who used the internet to express dissent in Syria were routinely locked up. While in Damascus recently, I heard of cases of student bloggers receiving prison sentences of up to five years for "security crimes" such as "spying". Crowds were expected to clap when the president's name was mentioned, even in the most mundane situations. Thousands of plain-clothes policemen from the Mukhabarat security service enforced co-operation.

Such methods have kept the Assad dynasty in power for 41 years, and there was no question that Asma did not know this. She would have been aware that her husband was last "elected" president in 2000, by 97 per cent of the population "agreeing" that he should succeed his father. Despite Asma's continual references to "religious harmony", it was her father-in-law who ordered the killing of up to 20,000 Sunnis in Hama in 1982.

There are sinister parallels between Hama and what has been happening in the city of Deraa, where Bashar's younger brother Maher, commander of the Syrian national army's 4th Armoured Division, has led the killing of civilian protesters. The feared paramilitary unit, manned mainly by Alawites, is responsible for so much bloodshed that the Assads refuse to allow in a UN humanitarian inspection mission.

It was into this sect, as insular as it is powerful, that Asma married. Though foreign journalists are officially banned from Syria, glossy western magazines have published profiles of her this year. A fawning interview appeared in the March edition of American Vogue (it has since been removed from the magazine's website), in which she was described as "a rose in the desert" whose household "is run on wildly democratic principles". For all its exaggerated deference, the article at least highlighted the crudely acquisitive nature of the Assads, who are said to have siphoned $40bn out of Syria.

Many first ladies are accused of being addicted to shopping, but Asma's obsession with jewellery, clothes and Louboutins (the French shoemaker, who owns an 11th-century castle in Aleppo, in the north, is a "personal friend") is real. She has enriched herself by marrying into the Assad dynasty, and seeks to cover its crimes with a polished veneer of respectability.

Feeble EU sanctions announced this month against 13 prominent figures, including the freezing of assets and a ban on foreign travel, have so far not been extended to Syria's president. He might still attempt to redeem his reputation by claiming that his calls for reform were overruled by hardliners inside his regime. That, however, would be about as convincing as Asma's promotion of "active citizenship".