Multiculturalism was once a byword for respect, equal rights and the celebration of diversity. It was the agreed common sense of the political mainstream and the liberal media. Now politicians of the right, academic gurus of the radical left and the assorted ranks of the commentariat compete to administer the last rites to its corpus of beliefs.

The climate of ideas began to shift against multiculturalism in 2001. The turning point was not 9/11 but a constellation of events: the riots in Bradford, Oldham and Burnley and a sharp increase in asylum claims, accompanied by daily images of young men scaling the fences of the Eurotunnel freight yards. As Labour’s second term progressed, fear of terrorism, anxiety about immigration and the looming war in Iraq combined to form a cocktail too lethal for the doctrine to withstand. Thursday 7 July delivered the coup de grace.

But what does multiculturalism actually mean? Leaving aside its ideological baggage, on one level it is simply a description of practices common to many progressive democracies: race equality strategies, public recognition of cultural diversity, and sensitivity, within the framework of public law, to religious beliefs.

But the recent challenges to multiculturalism raise questions. Do we need to do more to unite different communities around a core of common citizenship? Can we better tackle community segregation and the social exclusion of minority groups? Should we more forcefully insist on basic human rights and democratic norms against some of the claims of different cultures?

In recent years, Britain has undergone a quiet revolution in its citizenship policies. Citizenship education is now part of the school curriculum. Applicants for citizenship have to demonstrate a basic mastery of the English language and knowledge of British history and civic life. Thousands of people now gain citizenship at the local town hall rather than when a brown envelope falls through the letterbox. These practices, familiar to many other Anglo-Saxon democracies, have given greater content to the objective of promoting civic integration.

The difficulty arises when the integrative power of political citizenship is weak. Is it possible that we can share a language, democratic rules and habits of mind, and yet still live in segregated and culturally distinct communities? The experience of the 20th century would suggest that second and third generation migrants are more integrated than their parents. But in the context of rapid and continuous migration, those processes can weaken. Moreover, as recent experience in the UK shows, younger generations can face conflict between the customs and beliefs of their parents and those of the society around them. At an extreme, they may search for meaning in political discourses that reject both western liberalism and the moderate religious conformism of their parents.

These are questions for which we have few easy answers. An inclusive sense of national identity is important – feelings of patriotism are not the preserve of conservatives. Economic inclusion is also critical and the UK labour market is relatively good at absorbing migrants. Where the jobs market and local economies are weak, as in former textile towns, the problems of segregation are much more profound. We need a more sustained look at how to spread economic prosperity and social justice to these areas.

Britain is now home to a host of new immigrant communities from South Africa to Somalia, Australia to Afghanistan. Many are prosperous and well-integrated. But others have catastrophic levels of disadvantage, particularly those from war-torn backgrounds, such as Somalia, Ethiopia and the former Yugoslavia. Unless urgent action is taken to address unemployment and economic inactivity in these communities, they will be cut adrift from mainstream society.

The final challenge is where to draw the line on basic liberal rights and cultural practices. Outlawing forced marriages and female circumcision is straightforward. But other cases, such as the wearing of the jilbab in schools, are less clear.

In my view, public authorities have a duty to understand the depth of motivation that religious belief brings to individuals. But this sensitivity should not prevent forceful confrontation with irrational or oppressive beliefs. Children are denied their rights when they receive inadequate education in private religious schools. Muslim women have equal rights to live free and fulfilling lives, and should be supported in the assertion of those rights.

Recent events have reminded us of the importance of tackling political indifference to segregation, asserting liberal values and the need to inculcate a common core of political citizenship, but multiculturalism is far from dead. It is merely evolving, and through this process of negotiation we can renew our democracy, with greater strength in our diversity.