Leading article: Tolerance is a policy that has served Britain well

Since last month's bombings in London, a number of explanations have been put forward to make sense of the atrocity. One of the most popular appears to be that the bombings were a terrible by-product of Britain's policy of multiculturalism. The latest public figure to expound this thesis is David Davis, the shadow Home Secretary and Tory leadership contender. He argued that multiculturalism is dangerously flawed and that we should not be afraid to "speak openly of what we expect of those who settle here". The message is a simple one: the failure to impose British values on migrant communities has indirectly encouraged some young Muslims to embrace militant Islam.

This line of argument should be treated with extreme caution. Many of those arguing for the need to "impose" British values on ethnic minorities are the same individuals and organisations who have done most to demonise and scapegoat those groups over recent decades. And as the present climate of fear and violence towards Britons from ethnic minorities shows, this is no time to concede ground to the forces of bigotry.

Yet it must be recognised that the view that multiculturalism needs to be reassessed is not limited to the political right. Trevor Phillips, the chairman of the Commission for Racial Equality, argued not long ago that it is time to reconsider the value of the approach. Some liberal academics have also begun to express their concern at what they regard as the loosening of the bonds of British identity. There appears, however, to be a degree of confusion as to what multiculturalism was all about. Its intention was never to create ghettos or divisions. The main goal of multiculturalism was always to help migrant communities maintain their heritage, while helping explain to white Britons that migrants and any unfamiliar customs are not a threat.

Although this country can take some pride in its integration of ethnic minorities, the rise in race attacks and the tone of the debate over asylum underlines what lies below the veneer of British tolerance. We should be wary of holding up the supposedly mono-cultural France as a model. The National Front there routinely registers a significant vote, while France can boast Muslim ghettos to rival anything found in Bradford or Burnley.

Yet it is true that multiculturalism needs to be refined. A new language to describe cultural relations in the United Kingdom - jettisoning loaded terms like "assimilation" - would be useful. And a public discussion of the values that bind us together as Britons could help create the sort of civic culture that exists in America.

Another argument that has increased in popularity is the view that the Human Rights Act, based on the European Convention on Human Rights, has become an impediment to Britain's efforts to deal with terrorism, with calls to reverse the legislation. This is foolish and unjustified. For one thing, the Act has been responsible for a series of victories in the cause of social justice, such as securing next-of-kin status for those in gay partnerships. For another, the idea that the act is preventing us from dealing with terror suspects is entirely spurious. Critics of the act argue that it prevents the Government deporting extremists, but France and Germany are bound by the same European convention and yet have no problems deporting extremist Muslim clerics.

There should be a debate about how to make the country safer from this new threat. There should also be a public discussion about the future of multiculturalism. But fear must not prevent us from scrutinising each suggestion in exhaustive detail. We must not regress into tired, dated cliches and stereotypes. And we must be particularly careful not to compromise our liberal and tolerant values for vague promises of security.