@gman1225 I moved things over here so as not to further pollute the NK thread.
You mean integration I think. France is quite xenophobic, and citizens of North African descent as well as other minorities face big uphill battles in getting jobs from white owned companies and renting apartments from white landlords, let alone buying houses in white majority neighbourhoods. The pressures that formed these ghettos are similar to the pressures that caused predominantly black ghettos to form in the US.
The government did not see any reason to do anything about this until it was too late (i.e. no or very little positive push for integration from the top) and remains a big problem to this day.