Do we need to be concerned about such? "Civilization jihad" or "resettlement jihad" is known in the Islamic religion as "hijra." It's a sacred Muslim doctrine second only to jihad. The Islamic doctrine of hijrah means "conquest via immigration." There's been lot of talk in the news about the Muslim refugee crisis but none seem to be considering the doctrine of hijrah. Is that wise? Jerusalem was first taken through hijrah. Constantinople fell to Islam through hijrah. Has Immigration Jihad Come to America?