Post-immigration ‘difference’ and integration

In the twentieth century the United States was thought of as a place of racial and ethnic diversity but Europe thought of itself as a continent of white nation-states. Twenty-first century Europe, however, is going to be more like the USA – with the difference that the principal minority will be Muslims and the principal fault line may not be black/white but secular-Christian/ Muslim. What form should integration take in this socio-political landscape? What implications are there for a continent that thinks it is secular but where state support for religion is routine; and for Christianity as a cultural marker of Europe? I suggest some possible scenarios after having identified ‘group difference’ as the key concept by which to understand the normative orientations, and their implicit sociologies, of assimilation, individualist-integration, cosmopolitanism and multiculturalism