In France it's largely Islam and north-African immigrants. It managed to completely shatter the secular and assimilation/integration model that had worked for a

In France it's largely Islam and north-African immigrants. It managed to completely shatter the secular and assimilation/integration model that had worked for at least a century. But to answer more generally the loss of character does not have to come from a single place. In cities like London or Sydney you can see that the loss of character comes from 50 different countries.