Britain is in shock. Not just from the traumatic and grudging realization last Thursday that the country is at war, but from the discovery that the attack on London was the work of four suicide bombers, all of them young British Muslims. Readers of this column will not have been surprised by this realization, but it is only just dawning on the great British public that it has unwittingly harbored a terrorist cell in its midst, and that more “sleepers” may emerge to destroy us at any moment.

The uncanny dread that this knowledge engenders cannot be allayed by assurances from the authorities or from Muslim leaders that the attack on London had nothing to do with Islam. Such rhetoric has a hollow ring, now that we know the identities of the terrorists.

For these were ordinary young Muslims, born in Yorkshire to families who migrated from Pakistan a generation ago. One family ran a fish-and-chip take-away, another a grocery. Their fathers were pillars of the Leeds Muslim community. And yet these respectable families were incubating monsters who set off with backpacks full of explosives to kill and maim as many of their fellow countrymen as possible.

One of the suicide bombers, Hasib Hussain, aged 18, had recently returned from a pilgrimage to Mecca, having become a devout Muslim two years ago and grown a beard. According to friends,” he never came across as any sort of fanatic.” Shahzad Tanweer, 22, was a cricketer, who apparently told friends that he disapproved of the attacks on America of September 11, 2001. A third bomber, Mohammed Sidique Khan, was married and had become a father eight months ago. A fourth man, whose remains are still being identified in the grisly forensic operation in the subway deep below King’s Cross station, probably came from a similar background.

As long as the visible face of the Islamist threat in Britain was the one-eyed, hook-handed imam of Finsbury Park mosque, Abu Hamza, whom American authorities have accused of setting up a terrorist training camp in Oregon, the public could at least feel that they knew their enemy. The imam, who lived a few doors away from me in our quiet West London street until his arrest last year, looked and sounded like a demagogic fundamentalist. His trial on terrorism charges has only just begun, and it is a scandal that it took so many years to assemble a case against him, but he was too identifiable ever to blend into the crowd.

That is not true of the Leeds suicide bombers. None of them obviously fitted the stereotype of the religious and political fanatic. If these young men could suddenly turn on their neighbors and kill them, why should those neighbors trust other young Muslims? It is hard to believe that none of their friends and relations suspected anything, but if they genuinely did not, then the implications are even more alarming.

There are up to 3 million Muslims living in Britain, the great majority of whom are British citizens. If, as the security services believe, about 3,000 of them have been recruited and trained by Al Qaeda, then one in a thousand Muslims is at least a potential terrorist. But at the last general election the Muslim community voted en bloc against the Blair government, on account of its support for the Iraq war and the Bush administration. Opinion polls confirm that a large proportion of Muslims, perhaps as many as half, have at least some sympathy with terror attacks against America and Israel.

So the one-in-a-thousand who is prepared to die for Islam can count on a much larger number who at the very least will not lift a finger to stop him. What is the government going to do about them?

It doesn’t trust us enough to tell us the truth. We Londoners have been patting ourselves on the back about the lack of panic last Thursday, but it is now clear that the transport chiefs deliberately lied to us, claiming that a “power surge” had obliged them to close down the Underground, because they did not trust us not to panic if they admitted that we were under terrorist assault. Next time, nobody will believe such announcements.

It is also becoming clear that the government thought the British public would turn on their Muslim neighbors if it were told the truth. The police themselves have contributed to the myth that the real problem now facing us is not Islam, but Islamophobia. There have been a handful of incidents since last Thursday, but certainly nothing that could be called a backlash.

Yet the desire to prove that London’s Metropolitan Police is not Islamophobic has created grotesque examples of political correctness. Scotland Yard is contributing $15,000 of taxpayers’ money to enable a Swiss Islamist academic who is a recognized apologist for terrorism, Tariq Ramadan, to address a conference of young Muslims in London next month, despite knowing full well that Mr. Ramadan had been banned from America.

The result of this bad faith between the government and the governed is quite serious. Now that at last we know who and what we are up against, we are no longer sure that the authorities are on our side. The police protect Islam – I saw two constables standing guard outside the local mosque yesterday morning – but they are powerless to protect the rest of society against the Islamists. Exhorted to be vigilant, people fear accusations of Islamophobia if they voice their suspicions. It is so much easier to blame the Iraq war or the Americans or the Israelis than to face the horrific truth: that we now have a fifth column, nameless, faceless, and utterly ruthless, dedicated to transforming Britain into an Islamic republic.