In the hours after a young man was stabbed to death amid the Boxing Day sales crush on Oxford Street, the understandable desire on the part of almost everyone was to douse any panic. A killing on the capital's main shopping thoroughfare was highly unusual, it was said; the last had occurred almost four years before. It was an isolated incident, possibly gang-related; ordinary shoppers need have no fear.
And so it was that the street was hosed down and the police cordon shrunk in good time for the world to carry on spending yesterday. When the economy needs a fillip, you don't want to deter would-be spenders. Still less should you scare off new visitors, with the Queen's Jubilee and the London Olympics ahead.
Temperamentally, I am not usually given to panic, either. But I am less confident that there is nothing to worry about here. It is true that Oxford Street was never the Champs Elysées or the Via Veneto; it has its rougher end. And the improved transport of recent years has a less acknowledged downside: the Tube will whisk you to Oxford Street in minutes from a variety of less salubrious locales, as will a veritable fleet of buses.
When a new tram was introduced in Strasbourg, connecting neglected estates east and west, one consequence was a rise in city-centre crime. Fear of crime persuaded Washington DC's elite enclave of Georgetown to refuse a Metro station, leaving it dependent on surface transport – though hardly crime-free – to this day.
Yet the notion that Oxford Street and its environs, or even central London generally, are havens of civility, but for pickpockets, seems increasingly wide of the mark. If you go to Oxford Street on a weekend afternoon, you may find yourself swept along in a mass that is not always friendly and hustled into the road accidentally-on-purpose, while keeping tabs on close-knit posses of youths for whom shopping does not seem a natural leisure pastime. You might also catch yourself wondering where the boys (and girls) in blue are – notching up overtime at the football?
If you have known Oxford Street for some years, you might notice something else: the depleted ranks of what the Blair-Brown government called Britain's hard-working families. Most family groups are identifiably tourists. Even if you grant that London styles itself the youth capital of the world, the lack of the family part of the indigenous population on the nation's best-known shopping street should still give pause for thought.
You know where they are, as I do. You have only to go to certain outer suburbs, to the small towns and dormitories of south-east England, and to the shopping malls, such as Bluewater, Brent Cross and Westfield, to find mothers and fathers, toddlers and prams, and the whole glorious panoply of the family. House prices have taken them out of inner London, whether for living or shopping, and here they are, enjoying the greenery and the space. But is it just house prices?
The great move out of London comes not when children come along, but when they reach secondary school. Education, as much as housing, takes the middle class out of London – and, more and more, perhaps, a quest for safety. Shopping malls are the gated communities of commerce.
This may be the first actual killing on Oxford Street since 2008, but two male teenagers were stabbed outside an H&M shop in August. A year last March a 15-year-old was lynched by a mob of more than 100 teenagers, who pursued their quarry through Victoria Station at rush-hour. In recent months I have witnessed several incidents of minor violence on and around London buses in broad daylight and other instances of threatening behaviour, often between different races. And, of course, there were the August riots, which brought members of a whole urban sub-culture to the streets, of whom a disproportionate number were black and most of whom were already on the wrong side of the law.
You do not need to immerse yourself in the intricacies of so-called gang culture to draw two conclusions. The first is that visible policing, whether of city estates or of public spaces, such as Oxford Street, is absurdly inadequate. The liabilities of relying on CCTV to detect crime after-the-fact should be obvious; vastly better street lighting would also help.
The second is that established, middle-class, family Britain is in retreat from the capital in a way that risks an American-style hollowing out, with the very rich, the very poor and the newly arrived concentrated in an urban circle and everyone else clustered around the edge. Look at the last election results for London and the South-east. Look at the extent of de facto racial segregation in London's schools. Bear in mind that more than half of all children born in London are to foreign-born mothers, compared with 25 per cent nationally. Then ask whether the killing of Seydou Diarrassouba, at Foot Locker on Boxing Day, was a tragic accident, or – if these social trends continue – a sign of things to come.