Don't worry. After WWII, Europe put laws into effect that prevents that from ever happening again. However, the cost of those laws is that Europe can no longer enforce laws that focus on religion or any other group. So now Islam is having a field day - every Christian knows about the problems with Islam and are now powerless to do anything.
In 20 years, Europe will be a distant memory.
Well I guess we will just have to wait and see, I just don't think Europeans will let Europe fade away. Western Europe is and will always be the foundation of modern civilization.
what kind of laws do you mean?