Clash of civilisations leaves politicians confused

Great nations write their autobiographies in three manuscripts - the book of their deeds, the book of their words and the book of their art. Not one of these books can be understood unless you also read the two others. But of these, the only trustworthy one is the last (the book of their art).John Ruskin

A civilisation encompasses different cultures but all these cultures use the same basic ideas and technologies. With modern unifying technologies and hypercommunication all civilizatons on this planet tend to converge. In the end, only differences in cultures will be left.
But for the time being we can distinguish the following civilizations:
The Western Civilisation,
The Eastern Civilisation,
The Arabian or Islamitic Civilisation,
The Mid-African Civilisation which is actually a collection of different civilisations but these are too hard to distinguish for Western people so we leave it at that;
A few of prehistoric civilisations that are still alive and can be found in remote areas like the Amazon rainforest and the polar regions in the north.

From this simplified definition we can develop a better understanding of what is going on with immigration and why it bothers the populations of Western Europe so much even though they have had no problems with immigrations in the last five centuries.