Based on extensive statistics and his own calculations and forecasts, Thilo Sarrazin, a prominent politician and former senator of Berlin, convincingly shows that the Muslim community in Germany does not strive to integrate into German life. The level of education and labor participation of immigrants remains much lower level of the indigenous population, which, given the traditionally high birth rate among Muslims, poses a real threat to the country. The author speaks out for a tough migration policy and shows ways out of the crisis.