The flags are at half-mast in Westminster in a show of solidarity with Brussels, one of those ceremonies Europe seems to be getting used to. We’re long used to the statements of shock by politicians (why the shock?) as well as the platitudes about this having nothing to do with any particular religion. After that we have the now traditional focus of all our anger and grief towards Katie Hopkins, as if what she says or believes makes any difference to the growing problem facing Europe.

Not all of Europe, of course. Central Europe, chiefly Poland, Hungary and the Czech Republic, remain largely safe from the terror threat, despite the former in particular being a Nato player in the Middle East. It is precisely because the reasons for this are so obvious that they cannot be mentioned. Poland is 0.1 percent Muslim, most of whom are from a long-settled Tartar community, Britain is 5 percent, France 9 percent and Brussels 25 percent, and those numbers are growing.

For all the goodwill shown by the vast majority of people in Europe, Muslim and non-Muslim, and for all those things that shouldn’t have to be said - that most Muslims hate this monstrosity - these statistics correlate to terrorism risk. That’s not something people want to hear when they have a desperate urge to feel solidarity, but it is true nonetheless. It may well be that as the Muslim population increases in any European country, the radicalisation risk grows exponentially, since such extremism thrives on ghettoisation and isolation. Neither the French policy of integration nor the British model of multiculturalism can stop this. There is no sign of Islamism disappearing anytime soon. These problems will not go away. It is simply a facet of the multi-ethnic society we now inhabit.

After Paris I wrote:

“ Radical Islamism thrives in the absence of other identities, which is why it is especially prevalent among second-generation immigrants, who are more likely to feel alienated and torn between cultures. This alienation, which is reflected in statistics on mental illness among the children of migrants, is the flipside of what Salman Rushdie called the world of the “cultural mestizo” found in the arts; to the especially talented this provides the sort of confusion and nuance that might produce great novels or films but to others it brings great stress and confusion.

Religion provides the comfort of certainty, something politicians have failed to see because they have assumed that particular Western values are universal or inevitable, when they are actually quite unusual and fragile; this was reflected in Barack Obama’s statement that the Paris atrocities were an attack on “universal values”.

Added to this we have another serious problem, the growing absence of jobs for lower-skilled men, an explosive mixture in a Europe that has in many of its cities groups of men united by a universalistic religion with an ambivalent attitude to violence.

Central Europeans have become the new target for liberal snobbery in the past couple of years, their antediluvian attitudes to Islamic migration making them the new hillbillies; low-status whites it’s okay to mock on account of their views. But looking at what is happening in Brussels, London and Paris, is it not rather rational for them to look at Merkel’s open-borders policy and the whole multicultural thing with some scepticism? I suspect those flags will be back at half mast soon enough.