Three factors clarify Saudi Arabia’s intrinsic and total war on Isis. First, many people claim that Saudi Arabia is the source of Isis because both practise a version of Islam called Salafism (erroneously known in the west as Wahhabism). Salafism is rooted in the word salaf, or “forefathers”, and refers to the way the prophet Muhammad’s followers in the religion’s first three generations practised Islam. And while it is true that the kingdom espouses Salafism, Isis’s claim that it is Salafi has no theological basis, because the group is in fact a continuation of a crude sect known as the Kharijites, or the ones who “defected” from the Muslim community (ummah) during the reign of the fourth caliph Ali (whom the Kharijites assassinated). The Kharijites, like Isis, believe that whoever disagreed with them should be murdered as infidels (takfir), rationalised mass killings against civilians including women and children (isti’rad), and practised an extreme form of inquisition to test their opponents’ faith (imtihan).

Isis’s adherence to the Kharijite ideology is not the only reason it is not a true Salafi movement; it has also committed an act of disobedience that effectively nullifies its Salafi pretenses. In original Islamic scriptures and practice, the highest authority is the “guardian” of the ummah, (wali al amr). All religious, political and military powers are concentrated under this authority, which Saudi Arabia’s system best exemplifies in the modern world. In other words, King Salman’s legitimacy to rule is contingent on him being first and foremost the wali al amr of the people, and in return the people show their acceptance of his rule by proclaiming him as their ruler. This proclamation (bay’ah) is a contract between the ruler and the ruled in which the first swears to promote Islam and the welfare of the second, and the second swears to obey (ta’ah) the tenets of Islam and follow the first’s leadership. Should the first deviate from Islam, the second is obliged to replace him. The joint bay’ah of the ummah to the ruler is fundamental to Salafism and anyone that breaks the bay’ah – as Isis has done – can never again be considered a true Salafi.

Given the importance of the wali al amr to Sunni Islam, Isis and Saudi Arabia are locked in a theological struggle from which only one can emerge victorious.