There is a much larger issue here that Konrad tiptoes around.

Perhaps using science and reason would help describe the magnitude of a problem which is pan-European and worsening.  

Look at polling data across Islamic countries and Europe on the attitudes of Muslims to a broad range of issues and its not hard to see the problem. A significant proportion of this community is diametrically opposed to many of the common ideas our societies cherish. 

% support for sharia law, honor killings, subjugation of women, rights for homosexuals, violence against those critical of Islam, support for terrorism in the name of Islam..... and then do the math and the results should make us all uncomfortable. 

I put two links below as a start. 

http://www.channel4.com/info/press/news/c4-survey-and-documentary-reveals-what-british-muslims-really-think

http://www.pewforum.org/2013/04/30/the-worlds-muslims-religion-politics-society-morality/