Well, something’s got to change. Its a question of how
I think you're a step ahead in your question.
Europe has not decided what needs to be changed yet and you see the ambivalence expressed in this article.
When nationalism is depicted as extremism, then the nationalists become the extremists. And the solution becomes ... Eradicate the extremists.
Europe cannot decide how to deal with the "problem" until they figure out what the problem is.
If the European mindset is that immigrants are necessary to support their bloated social welfare apparatus, then controlling their borders means having to do something to replace the immigrants. Are they willing to have more children ... I doubt it. Is it too late for that ... Probably.
Until they decide what the problem is, they will have no idea what to do about it. Immigrant behavior is not going to change, they are getting the worthless from those societies.
Expect government violence directed against those that oppose government policy.