The diabolical atrocities we are witnessing in these days, are to a great extent the result of Western free society letting salafist ideologies blossom in muslem communities, which somehow legitimizes them. At the heart of this problem lies, of course, a cultural conflict: islam being both a religion and a culture, without division of religion and state as has developed in the West, can only be integrated in Western societies if it accepts the same limitations and restrictions as other religions in the West have been forced to implement under the pressure of secularist Enlightenment values as far as they (the latter) are supposed to regulate public space and thus, politics. Only within the framework of a secular society where religion is a private concern, different religious world views can live next to each other. This does not mean that religion is not important, but that religious world views which claim truth over other religious world views, are not allowed power in the public realm, so that religious freedom be maintained.
Culture operates often with the means of symbolism. The arts are strongly symbolic, as Duchamp's urinal demonstrates as clearly as Tintoretto's 'Deposition of Christ'. There is a deep instinct in humans to seek the support of symbolism under the pressures of life, hence the strongly symbolic nature of religious rituals. The more immigrants feel they are not allowed to share the benefits of Western society, the more they will cling to compensating symbolism, which creates the humus on which perverse ideologies can foster their hatred.
The problem with Western-born terrorism is not immigration or islam in itself, but education. The better Westerners understand their own society, the more chance newcomers will become, over time, Westeners and will no longer be immigrants. But a Western society which has lost its belief in itself and in its values, a society which cultivates egalitarian relativism and nihilism (as symbolically represented in the museums of contemporary art and at new music festivals), and which celebrates its creativity in the form of pop and commerce, will find it very hard to help people from other cultures where such self-defeating ideas have not as yet taken root, integrate. The West should not merely present its urinal to newcomers, but something of the best that has developed here.
How come that an over-developed society neglects the growth of such potentially dangerous ideologies in its midst? Recent history demonstrates how important it is to keep an eye on mental abberations that seek to destroy civilization, as in the thirties. I think there are at least three conspicuous, interrelated reasons: the notions of freedom, relativism and multiculturalism.
Freedom: as we know, human life is per definition not 'free' but limited on all sides by physical and circumstantial restraints, and whatever freedom there is to obtain in life, has to be created, to be striven after and often to be fought for (as any conductor knows all too well). As long as too many people in a society are incarcerated in circumstances not of their own making and don't have any means to overcome them, living in 'the free West' becomes meaningless; they may decide to vote for Trump or Le Pen or a brexit or to opt for a world view which promises them an unimaginable number of unspoiled virgins in heaven as a reward for fighting these circumstances.
Relativism: the idea that values are merely human constructs and do not relate to some objective truth, of whatever kind, denies a deep human need to find meaning in a world seemingly determined by blind natural forces which in themselves don't provide any meaning that can be experienced as such. To some extent values are indeed human constructs, as the many different forms of culture are, but underneath there is a universal basis which is related to how the human mind works: we can call them 'universal values', operating on universal dynamics defined by biology, as expressed in the 'holistic nature of human perception' (Steven Semes) and which is currently being confirmed by neurobiological research. The reason that so many migrants come to the West, otherwise than for pure survival as war refugees, is because these deeper inner needs are not answered in the areas they come from. Being fed with mostly misleading images in the media about Western life, the infantilism of which may relate to underdeveloped people in desastrous circumstances, migrants naively assume that once arrived in Europe, by whatever means, they will be able to share the normal life of the West, with a normal house, nice job, nice clothes, cell phone and possibly a blitzy car. The thought that 'they' might actually be like us, sends the European rightwing extremists into the curtains, but it does not automatically follow that the West should open the doors to the millions of the world. The only conclusion would be that the West - next to controlled immigration - has to contribute to improvement of other areas of the globe out of a sensible sense of selfpreservation, strengthening and helping to liberate the above-mentioned underlying universal values. It will be clear that a self-defeating relativism and lack of confidence in Western universal values won't be of much help in such policies.
Multiculturalism: Western imperialism in the past, which tended to view other cultures as 'primitive' and open to exploitation, has created a strong backlash of penitence so that immigrants from non-Western cultures are encouraged to keep their own home culture as much as possible when living in the West, which unintentionally hindered integration in society and the development of understanding of Western values. It is the old story of the child and the bathwater: some of these Western values are mere culture like dress, hand shaking, hair grooming, traffic rules and eating habits, and others are universal and were thus feeding the wish to migrate at all. Hence the continuation of certain entirely unacceptable cultural traditions like genital mutilation, the suppression of women, forced arranged marriages, the condemnation of homosexuality, family violence, sharia law etc. etc. - that is: unacceptable according to Western values and not values as a mere human construct, but as universal, civilizational values. The wearing of a head scarf or turban, or avoiding porc, or keeping the ramadan or the sabbath, are phenomenae on the level of culture (however religiously inspired), but the mentioned abberations are in conflict with the level of universal value, they are primitive and need to be overcome, wherever they are practised, not only in the West. The blindness to this distinction, in the understandable penitential mood of the 20th century, has had enormous consequences which are now surfacing in the disruptive violence which is now so often in the daily news. But this does not mean that the idea of a multicultural society is a mere pipe dream. Different cultures can live perfectly well within the framework of a relatively (!) free society where the rule of law is based upon these deeper civilizational values which are longed for by all human beings, and at large such a multiculti world is already functioning well, proving the point. Civilization is not dependent upon culture but can outgrow its cultural roots and become universal. Therein lies our hope.