A leading French political scientist Olivier Roy from Paris well known for his studies and research into the radicalization of refugees and radicalization in general for over 20 years ....openly challenged Trump and many US commenters in their statements on refugees and Muslims in general........

There has been not a single recorded attack in Europe that was committed by a true registered refugee and or a member of that family...none whatsoever.....

Did and does IS and even AQ use the human smuggling route to slide their fighters back into Europe yes they did and still do....but these individuals are not the same as a true refugee...

Most of the attacks in at least Germany do/did not require an extensive logistics support group....and were often spontaneous in nature and not well planned out by those individuals radicalized before coming to say Germany...

Or they came out of immigrant families who basically had become German citizens and or were living/working for long periods inside Germany...the same exact thing occurred in France....

NONE of the current IS attacks were carried out by true registered refugees....

THAT is something Trump seriously needs to think about and fully understand in his demands for register all Muslims and ban all Muslims from entering the US.....

ALL he is doing is in fact playing the dog whistles of blatant racism.....AND providing IS and AQ excellent propaganda that proves them correct in their assessments of the West....