The ambiguous boundary provisions of this treaty had done little to help the relations of Iran and Turkey. The same vague provisions had been confirmed in the peace treaty of 1746 that terminated Nadir Shah’s war with Turkey.The problem of the controversial boundaries continued into the nineteenth century. Whether the war between Iran and Turkey which started in 1821 was instigated by Russia, or by Great Britain, the ambiguous terms of the old boundary treaties did not help the situation. The immediate cause of the war was, however, a dispute over wandering tribes. In 1821 the seraskier of Erzerum (in Turkey) and the governor of Tabriz (in Iran) wrangled over two wandering tribes which Iran claimed as its subjects and to which Turkey offered protection. The Turkish seraskier imprisoned an Iranian agent who was dispatched to him to present Iranian grievances. Fath Ali Shah regarded the event as an insult and ordered the Iranian forces to attack the Turkish territory.
The armed clash dragged on until 1823, when, as the result of British mediation, a new peace treaty was signed at Erzerum. The Treaty of Erzerum, like its predecessors signed in 1639 and 1746, failed to come to grips with the boundary dispute and the related problem of the tribes. Instead, it confirmed the terms of the previous treaty (signed in 1746) and confined itself to the two tribes, Hydranlo and Sibiker, over which had arisen the dispute that precipitated the war.
The failure to demarcate the boundary definitively led to further tense relations between the two countries. Soon after the Treaty of Erzerum was signed, claims and counterclaims began to mount. Iran complained that some of its Kurdish tribes had been “unfairly” abstracted from its territory and demanded pecuniary compensation for having allowed the Turkish tribes of Sulaymaniyah to pasture their flocks on Iranian soil during the summer months. Turkey protested Iran's retention of the district of the bridge of Zohab on the frontier of Kermanshah. From 1834 to 1840 tensions increased dangerously. The districts of Kotur and Khoi were ravaged, the district of Margavar was plundered, and Turkish troops attacked and demolished the commercial town of Mohammarah. Iran demanded immediate satisfaction. The Porte retorted that Mohammarah, like Basra and Baghdad, belonged to Turkey, and no compensation was due. In the meantime a number of the Shff inhabitants of Kerbela were murdered.
War between Iran and Turkey threatened, but British mediation averted it. Great Britain’s active conciliatory efforts, beginning in 1842, added an international dimension to the boundary dispute. British interest in the boundary settlement was both political and commercial. The Foreign Office feared that more armed clashes between the two Muslim states would further weaken them. This was contrary to the British policy for the Middle East, as these states separated the possessions of Russia from those of Great Britain in India. Great Britain was also interested in opening new channels of commercial intercourse with the East through the Irano-Turkish domains. It was hoped that the activities of British agents in the border areas in connection with boundary demarcation endeavors would produce useful knowledge in regard to “these little known areas.”