How Germany's open-door refugee policy helps fight terrorism

In Germany, this policy is already delivering results with vital intelligence being passed by resident Muslims to the country’s domestic security service, the BND.

There is also evidence around the case of the Berlin market investigation that community informants have played their part in warning about the threat posed by prime suspect Anis Amri before the attack. An informant tipped off security services when he attempted to buy a gun.

Intelligence from security agencies is almost always based on pointers gleaned from agents (not officers) working within the Muslim communities. Counter-terrorism operations tend to be intelligence-led but the security services never identify their sources.