It will come to that. We may not know what the breaking point is either in terms of the operational support or of the public being willing to put up with it, but there is a point where govts will say “no more”. If Europe takes in a couple million migrants this year, can they take in 10 million next year? If they find a way to do that, can they then take in 100 million the year after? There are untold millions of people in the Muslim world and in Africa who are willing to allow Europe (and the US if we let them) support them.