Complex sentence: Wilson, p.100 In the north the division was mainly responsible for the security of the port of Haifa, the largest in the country, where they protected oil installations, the Mosul-Haifa oil pipeline and prevented illegal immigrants landing on the coastline.
Split into simpler sentences: Wilson, p.100 In the north the division was mainly responsible for the security of the port of Haifa, the largest in the country. Protecting oil installations and the Mosul-Haifa oil pipeline and to prevent illegal immigrants landing on the coastline.