Add to this the moral degeneracy and godlessness of the Western World and you have a very potent mixture. This degeneracy only validates in the Muslim mind the outlooks and attitudes of the Koran in regard to Christians and Jews and confirms their satanic nature.
Now add another ingredient to the brew: the stance of at least some Muslim clerics that mass murder of infidels is morally justified, and indeed is a righteous act of great merit, and that a person who sacrifices his own life in the act of killing infidels will be rewarded by God with the highest heaven.
With a soup of this mixture it is easy to understand all the violent, shocking acts of terrorism and mass murder in regions everywhere in this world where the Muslim world interfaces with the non-Muslim world --- where you see Muslims rubbing shoulder to shoulder with Jews, Christians, Hindus or some other religion. And you wonder about the prudence of the West in welcoming into their midst people of this particular outlook.
You also wonder how societies holding the ideal of freedom of religion can accommodate people with such outlooks.
Too many westerners have their head in the sand and we are all going to pay the price for our ignorance, by choice.