Leading article: The bombs that risk driving us apart

Londoners were not intimidated. But that strength contains a risk: that we underestimate the terrorist threat

The seventh day of the seventh month one year ago was the day Britain lost its illusions. Fifty-two people died that morning in four separate explosions. Hundreds were injured; many, many more had their lives changed irrevocably. It was the very atrocity - multiple attacks on the very centre of London at rush-hour - that the Government and the intelligence services had feared.

That day shattered any illusion we might have had that this country was impregnable or somehow inoculated against terrorism because of our experience at the hands of the IRA. The red bus standing gashed and forlorn in a sunlit Tavistock Square remains the indelible image: the quintessentially normal mutated into horror. The frames flashed from mobile phones captured the claustrophobic confusion of the disaster underground. But it was the live testimony of survivors that brought home the inherent vulnerability of a modern public transport system to a determined and well-planned attack.

The second illusion we lost was the extent to which our intelligence and emergency services would, or could, be prepared. Even if the intelligence services were fleetingly aware of one or two of the bombers, they did not treat them as a serious threat. The alert level in London had been reduced only days before the attack.

With the emergency services, the lessons from the US experience of 11 September 2001 turned out either not to have been learnt or not to apply. Many have paid tribute to the courage, compassion and often heroism of those who came to their aid. Of necessity, there was improvisation; individuals showed extraordinary resourcefulness and generosity.

Yet some of the most basic components of urban emergency relief were missing. Communications were a shambles. Tube staff and emergency workers underground could not communicate with the surface. Mobile phone circuits were taken out of operation, leaving not only civilians, but police, fire and ambulance staff with no means of contacting each other.

Also dispelled was a third illusion about any complacency we might have felt about the contentment of Muslims in this country. It may be true that relations between ethnic and religious groups in Britain are more relaxed and positive than in many countries that are our near-neighbours. But the events of one year ago showed that multiculturalism as practised here provided no defence against a few radicalised individuals prepared to die for their cause. The four suicide bombers may or may not have been part of a wider network, but they were British citizens, educated in Britain. They were home-grown militants who acquired their disaffection here.

The fourth illusion, more common among politicians than in the public at large, was that Muslims, here and elsewhere, were unaffected by Britain's involvement in Iraq. This was an arrogant invasion of a Muslim country based on erroneous intelligence. The idea that it should have no repercussions on inter-ethnic relations or national security is quite wrong. Quite how wrong is clear from videos of two of the bombers, the second released only yesterday.

Against these discredited illusions, one view of ourselves remains intact, even reinforced. Londoners, by birth, residence and adoption, not only proved themselves cool-headed, resourceful and humane in this emergency, but admirably resilient. The economy recovered quickly, as did daily life in the capital. We went back to work; the tourists returned. Reviving something of the Blitz spirit, we have not been intimidated.

Such strength is as impressive as it is healthy. But it also contains a risk: that we underestimate the terrorist threat, which undoubtedly persists. So long as this Government is in power, however, there seems little danger that the threat will be overlooked. On the contrary. After a dignified initial response to the bombings, in which he pledged a considered response and an all-party approach, the Prime Minister opted instead for repressive legislation that shamelessly exploited the national security issue for party political advantage.

Detention for 28 days without charge is now on the statute book, and likely to be extended. The timetable for introducing ID cards has been speeded up. And while the judges have fought valiantly against the more restrictive measures - the most recent being control orders - the legislative climate has become harsher. So, many young Muslims report, has the climate on the streets, where they feel the target of suspicion and hostile attention, not only from some sections of the public, but from the forces of law and order.

The police, having acquitted themselves with distinction in the days following the bombings, showed a panicked lack of professionalism when they tracked and killed the Brazilian electrician, Jean Charles de Menezes. The mistake was compounded by a scandalous lack of frankness and by a bumbling performance - neither his first nor last - by the head of the Metropolitan Police, Sir Ian Blair.

Subsequent exercises have also shown that some of the most elementary lessons of last year have not been learnt. The emergency services are still poorly equipped to communicate. And the massive raid conducted last month on a house in east London demonstrated not only the continued inadequacy of intelligence, but the capacity of the police for crass insensitivity.

Perhaps the most egregious failure, however, is the Government's steadfast refusal to call a public inquiry. The attacks constituted the greatest peacetime atrocity this country has known. The various police inquiries and the neutral "narrative" the Government commissioned are no substitute for a comprehensive investigation conducted in the public eye. Ministers' arguments - cost, manpower and the rest - are spurious. If ever anything demanded a public inquiry, it is this.

Today there will be a sequence of low-key commemorations, appropriate to this first anniversary. Relatives of those killed have rightly been concerned to prevent politicians of any stripe making capital from their grief. One year ago London ran the gamut of emotions: from joy at winning the 2012 Olympic Games to grief for the victims of the bombers. Those 48 hours brought the country together. We must ensure that the longer-term response, with the prospect of more illiberal laws and heightened suspicion of the Muslim minority, does not end up driving it apart.