In this preview, the former head of counterterrorism for MI6 Richard Barrett suggests the attacks in Paris are meant to polarise societies.

"The whole point of terrorism I believe, particularly the form we're seeing in Syria, is to force people off the fence," Barrett tells Mehdi Hasan. 

"You have to take sides… And that polarisation of society is a very important element of the Islamic State [ISIL] strategy." 

Barrett also says the attacks have "eroded" the idea of a 'grey zone', of Muslims living comfortably as Europeans, Americans and Canadians. 

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Source: Al Jazeera