An excellent essay from Dr. Guy Millière at Gatestone:
"Decades ago, Europe's leaders adopted a general policy of "openness" to the Islamic world in general, and the Arab world in particular. They decided to welcome migrants from the Muslim world by hundreds of thousands but without asking them to integrate. They made cultural relativism and multiculturalism their guiding principles. They acted as if Islam could mingle in the Western world harmoniously and without difficulty. Europe's leaders disseminated the idea that the West was guilty of oppressing Muslims and had to pay for its sins. They therefore sowed the seeds of anti-Western resentment among Muslims in Europe."
"When in the Muslim world jihadis started to kill, Europe's leaders wanted to believe that the attacks would take place in the Muslim world only. They thought that by not interfering with what European jihadis were planning, they would not risk jihadi attacks on European soil."
"When Jews were attacked, Europe's leaders decided that the problem was not jihad, but Israel. They stressed the need not to "export Middle East conflict in Europe." Hoping to please followers of radical Islam and show them Europe could understand their "grievances," they placed increasing pressure on Israel. They also increased their financial and political support for the "Palestinian cause."
"When Europeans were attacked, they did not understand why. They had done their best to please the Muslims. They had not even harassed the jihadists. They still do not know how to react."
"Many of them now say privately what they will never say in public: it is probably too late."