Also on VF.com: a Q&A with Christopher Hitchens about this column.

They say that the past is another country, but let me tell you that it's much more unsettling to find that the present has become another country, too. In my lost youth I lived in Finsbury Park, a shabby area of North London, roughly between the old Arsenal football ground and the Seven Sisters Road. It was a working-class neighborhood, with a good number of Irish and Cypriot immigrants. Your food choices were the inevitable fish-and-chips, plus the curry joint, plus a strong pitch from the Greek and Turkish kebab sellers. There was never much "bother," as the British say, in Finsbury Park. Greeks and Turks might be fighting in Cyprus, but they never lifted a hand to one another in London. Many of the Irish had republican allegiances, but they didn't take that out on the local Protestants. And, even though both Cyprus and Ireland had all the grievances of partitioned former British colonies, it would have seemed inconceivable—unimaginable—that any of their sons would put a bomb on the bus their neighbors used.

Returning to the old place after a long absence, I found that it was the scent of Algeria that now predominated along the main thoroughfare of Blackstock Road. This had had a good effect on the quality of the coffee and the spiciness of the grocery stores. But it felt odd, under the gray skies of London, to see women wearing the veil, and even swathed in the chador or the all-enveloping burka. Many of these Algerians, Bangladeshis, and others are also refugees from conflict in their own country. Indeed, they have often been the losers in battles against Middle Eastern and Asian regimes which they regard as insufficiently Islamic. Quite unlike the Irish and the Cypriots, they bring these far-off quarrels along with them. And they also bring a religion which is not ashamed to speak of conquest and violence.

Until he was jailed last year on charges of soliciting murder and inciting racial hatred, a man known to the police of several countries as Abu Hamza al-Masri was the imam of the Finsbury Park Mosque. He was a conspicuous figure because, having lost the use of an eye and both hands in an exchange of views in Afghanistan, he sported an opaque eye plus a hook to theatrical effect. Not as nice as he looked, Abu Hamza was nonetheless unfailingly generous with his hospitality. Overnight guests at his mosque's sleeping quarters have included Richard Reid, the man in whose honor we now all have to take off our shoes at the airport, and Zacarias Moussaoui, the missing team member of September 11, 2001. Other visitors included Ahmed Ressam, arrested for trying to blow up LAX for the millennium, and Nizar Trabelsi, a Tunisian who planned to don an explosive vest and penetrate the American Embassy in Paris. On July 7, 2005 ("7/7," as the British call it), a clutch of bombs exploded in London's transport system. It emerged that one of the suicide murderers had been influenced by the preachings of Abu Hamza, as had two of those attempting to replicate the mission two weeks later.

In fact, the British jihadist is becoming quite a feature on the international scene. In 1998, six British citizens of Pakistani and North African descent along with two other British residents were arrested by the government of Yemen and convicted of planning to kidnap a group of tourists and attack British targets in the port of Aden (scene of the near-sinking of the U.S.S. Cole two years later). One of the youths was the son of the tireless Abu Hamza, and another was his stepson. In December 2001, Richard Reid made his bid on the Paris–Miami flight. By then, two or three Britons had been killed in Afghanistan—fighting on the side of the Taliban. The following year came the video butchering of Wall Street Journal reporter Daniel Pearl, whose abduction and murder were organized by another Briton—a former student at the London School of Economics—named Ahmed Omar Saeed Sheikh. And the year after that, two British-passport holders, Asif Mohammed Hanif and Omar Khan Sharif, took part in a suicide attack on Mike's Place, a Tel Aviv bar.