From the outside, then, there is a sizeable overlap between Islam and Judaism and Christianity, not to mention ancient pagan practices. One idea that differs from these other faiths is jihad, the holy war, espoused by certain small sects as the controversial sixth pillar. The Qur’an does specify that one of the duties of Islam is to keep pushing back the geographical boundaries that separate the dar al-Islam, the land of Islam, from the dar al-harb, ‘the war territory’, but the extent to which this is to be achieved by war, and how ‘war’ is to be understood, is far from clear.
