A far simpler and thus likelier explanation is that European countries are universally naive in their application of religious freedom and support for local min

A far simpler and thus likelier explanation is that European countries are universally naive in their application of religious freedom and support for local minorities. Those ideas and laws came about before jihadism and the famous long arm of Ankara became what they are today. A cleverer approach is what is needed, more cognisant of the way that, for instance Ankara and Ryad, sponsors and instructs mosques in Europe. That sort of control should and can be severed, bringing migrants, sometimes already 3rd generation, definitively on board. I can tell you intelligence agencies are generally aware of this, but have no clear mandate to act. A confused and mostly wrong public opinion and politicians are not helping this.