A fifth of Europe will be muslim by 2050

I think they're low balling the estimate. Telegraph

Britain, Spain and Holland will have an even higher proportion of Muslims in a shorter amount of time, an investigation by The Telegraph shows

Last year, five per cent of the total population of the 27 EU countries was Muslim. But rising levels of immigration from Muslim countries and low birth rates among Europe's indigenous population mean that, by 2050, the figure will be 20 per cent, according to forecasts.

Data gathered from various sources indicate that Britain, Spain and Holland will have an even higher proportion of Muslims in a shorter amount of time.[...]

Although some polls have pointed to a lack of radicalisation in the Muslim community, little attention is being given to the integration of migrants, it is claimed, with fears of social unrest in years to come.

If not a Balkan style war.