Tensions are rising between Iran and Azerbaijan over Baku’s plans for a land connection to its exclave of Nakhchivan via Armenian territory, threatening to undermine Turkish-Iranian ties as well.

The wrangling between Tehran and Baku has escalated since Iran held military exercises on its border with Azerbaijan last month, including drills on crossing the Aras River, which forms part of the frontier. Simultaneously, Iran opened a consulate in Syunik, the southernmost Armenian province that borders Iran and is at the center of the tensions. 

The hostile exchanges resulted in mutual notes of protests earlier this month as both the Azerbaijani ambassador in Tehran and his counterpart in Baku were summoned by the respective foreign ministries. 

Apprehension is rife in Tehran that Azerbaijan, emboldened by its victory over Armenia in a 2020 territorial war, seeks to redraw borders by taking control of a strip of territory across Syunik, which separates Azerbaijan proper to the east and Nakhchivan to the west. As part of the cease-fire terms, Armenia pledged to allow transportation links between Azerbaijan proper and Nakhchivan — a route that Baku calls the Zangezur corridor and has threatened to secure by force if need be. Iran worries that Azerbaijani control of the strip could cut its border connection with Armenia. For Turkey, it would mean a direct land link with Azerbaijan via neighboring Nakhchivan and a route to Central Asia bypassing Iran.