In the 1995 French film La Haine, youth gangs in the bleak housing projects of the Parisian suburbs go to war with the forces of law and order after a young man is beaten up in police custody. The film was a powerful comment on alienation in the impoverished estates that ring Paris and provoked shock and anguished debate about police brutality, racial tensions and urban deprivation.

It seems that little has been learnt by the French authorities in the intervening years, if the running battles playing out in the north-eastern suburbs of Paris are anything to go by. For over a week now, youths have rampaged and rioted, set cars ablaze, firebombed schools and shops and even fired shots at police. The government's response - to dispatch more and more shield-carrying, heavily armed riot police into the affected areas - has done little to calm tensions.

The immediate trigger for the unrest was the death by electrocution of two teenagers, apparently fleeing a police search in Clichy-sous-Bois. There has doubtless been a copy-cat element to the spread of rioting from Clichy to neighbouring estates and suburbs. But France's political leaders would be ill-advised to ignore the causes of the very real anger and frustration which is exploding in these run-down ghettoes. It is not a coincidence that the areas in ferment are populated almost exclusively by families of North African or African ethnic origin. They are also blighted by chronic unemployment and sub-standard housing, and are subject to extremely heavy-handed policing.

The attitude of the Interior Minister, Nicolas Sarkozy, illustrates part of the problem. He regards the disturbances solely as a matter of law and order. It is unsurprising that his call on police to "hose down" the "scum" has only exacerbated things. Instead of playing to the far right, as Mr Sarkozy has done, the Chirac government should urgently find ways to mediate with community leaders and review its policing methods.

In the longer term, the crisis should serve as a wake-up call. On paper, the marginalised of the banlieues are as French as Mr Sarkozy. Yet even when they crave integration and acceptance in French society, they are frequently feared and discriminated against, banished to the farthest-flung estates from where chances of escape or employment are slim.

The French may scorn Britain's policy of multiculturalism, but these riots must surely confirm the failure of the French insistence on integration and assimilation. In practice, decades of neglect of the problems of immigrant minorities have led to deepening alienation. The violent consequences of that neglect are now unfolding on the streets.