"The question of offensive jihad is ... complex and controversial," writes Habeck. "The most widely respected Islamic authorities ... all assume that Muslims have a duty to spread the dominion of Islam, through military offensives, until it rules the world. By the 'dominion of Islam' these authorities did not mean that everyone in the world must convert to Islam, since they also affirmed that 'there is no compulsion in religion,' rather that every part of the Earth must come under Islamic governance and especially the rule of the sharia.
"Azzam's definition of offensive jihad (Azzam is the principal modern theorist of militant Islam) follows this traditional understanding of jihad, noting that it is a duty for the leader of the Muslims 'to assemble and send out an army unit into the land of war once or twice every year.'" The jihadist is obliged to perform with all available capabilities "until there remain only Muslims or people who submit to Islam."