Mansour Almarzoqi, an academic and researcher on Saudi politics at Sciences-Po Lyon, France. Follow him on Twitter @0Albogami.

Iran’s sphere of influence in the region is built on two factors: a regional atmosphere of sectarian conflict and weak central governments. This is also exactly the same environment where the Islamic State (IS) can operate most effectively. In the end, by expanding its influence, Iran paves the way for the expansion of IS, and vice-versa. 

Because of isolation and economic sanctions, Iran has not been able to rely on the usual tools of the nation-state to influence players in the international arena. Consequently, Tehran resorted to non-state actors, such as Asaib Ahl al-Haq in Iraq, Hezbollah in Lebanon, and the Houthis in Yemen. To build alliances with these non-state actors and influence their behavior, Iran has relied on sectarianism as a tool. Hence, it is no coincidence that all these groups are affiliated to Shia Islam. Nonetheless, in order for these non-state actors to be effective in recruitment and mobilization, there must be a heightened sense of sectarian identity, which they can seek through sectarian conflict. In addition, central governments must be weak, or else non-state actors would not be effective. But these factors, which favor Iran, also pave the way for the expansion of IS. 

Moreover, IS maintains that Iran and the West seek to establish a new Sykes-Picot agreement, negotiating the division of the region once again. In that regard, IS insists that Saudi Arabia is too weak to become independent of Western influence or confront Iranian expansionism. So the group asserts it is the sole actor capable of countering Iranian and Western influence in the region, and therefore everyone must join it. 

But when Saudi Arabia started the “Decisive Storm” campaign in Yemen to restore the legitimate government and stop the Houthi invasion of Yemeni cities, the kingdom demonstrated its ability to act independently of the West and its determination to confront Iranian expansionism. Thus IS and Saudi Arabia are engaging in one-upmanship. The Islamic State is now forced to show that it is the only defender of Sunni Islam, hence its attacks on Shia in Saudi Arabia and Kuwait. And building on this argument, Iran has been able to claim to Arab Shia that their sole choice is between submitting to IS or to Iran.