Turkey’s quest for a military campaign to drive Kurdish militants out of the northern Iraqi region of Sinjar has refueled the Turkish-Iranian rivalry for influence in oil-rich Mosul, which many Turks see as a lost Ottoman legacy.

Earlier this week, Iranian Foreign Minister Mohammad Javad Zarif was quoted as saying that Tehran “reject[s] the Turkish military presence in Syria and Iraq and consider[s] Ankara's policies toward Damascus and Baghdad to be wrong.” In remarks to a Turkish news agency, an unnamed Iranian Foreign Ministry official denied Zarif had made the remarks, yet the rift between the two countries is showing on the ground. 

While Turkey was targeting camps of the outlawed Kurdistan Workers Party (PKK) in the Gara mountains in northern Iraq in mid-February, the Popular Mobilization Units — an Iranian-backed Iraqi militia known also as Hashd al-Shabi — deployed three brigades to Sinjar, which lies to the west of Mosul along the Syrian border. Militia commanders made it clear the deployment was meant to counter Turkey’s “threat” in the region. 

Turkey cites the PKK presence in Sinjar as the cause for its concern, but its calculations go farther to Mosul. Iran, for its part, highlights the need to prevent the revival of the Islamic State, but it, too, has a broader calculus.