On the Fact that There Are Just Three Legitimate Tools In a Seventh Century "Take Control of the World" Tool-Kit; Conquest, Mass Migration, and Increased Fertility Rates, that's it

 And since the Islamists don't have the chops to conquer us, they're obviously using the other two tools (flooding the West with their Muslim brethren and popping out as many little Muhammads as possible). Oh boy, are they ever.