This becomes a problem (in true Nation-States) if you have some communities that have values that are fundamentally opposed to the values of the Nation itself.

This becomes a problem (in true Nation-States) if you have some communities that have values that are fundamentally opposed to the values of the Nation itself. To take a recent example : homeschooling is now effectively banned in France due to the (reactionary) Muslim threat. (Personally, I'm still unsure as of whether this was the best way to go about it, especially considering how it comes together with an attempt to create a Muslim clergy, which not only seems to go against the (majority) Sunnite practices (closer to Protestants than the better known Catholics which serve as the model here ?), but also puts at the head of it an association with terrorist ties (ties to the Muslim Brotherhood), and finally violates the core principle of separation of Church and State...)