Another threat to Europe is demographic.
That is low birth rates and high rates of immigration.
This is a very difficult issue if you have no heart, and a very easy one if you do.
For anyone with a heart or a soul or a mind, the prospect of the fading away of beautiful, ancient and not-infrequently noble European cultures is a very sad thing.
Also anyone with a conscience, must know that first and foremost we are humans, and that over-rides our national and ethnic differences, which are really quite minor and as such it is our duty to do what we are able to help those in desperation without prejudice.
And furthermore the kinder a society is to immigrants the better it is at integration.
The more anger and resentment builds up among disparate communities and across borders the more dangerous the everything becomes.
Sometimes the refuge given is only given grudgingly, and that sort of kindness often turns out to be a very poor type of kindness.
But the practical fact of the matter is that nature abhors a vacuum, and demographically, culturally, economically, religiously a vacuum is what Europe has become, so it is inevitable that it will draw in new people and draw in ideas and draw in cultures and religions, while the efforts of the far right only make Europe more vacuous.