A poem recited by Turkish President Recep Tayyip Erdoğan on an official visit to Azerbaijan has angered the Iranian government, which has accused Ankara of meddling in internal affairs.
The Turkish president visited the Azeri capital Baku and observed a military parade celebrating the nation’s victory over Armenia in the Nagorno-Karabakh war that ended last month.
During the event, President Erdoğan recited a 19th century Azeri poem that highlighted the division of Azerbaijan’s territory between Russia and Iran, an act which Tehran says fans the idea of separatism in its Azeri-majority north.
In a statement on Twitter, Iranian Foreign minister Javad Sharif wrote:
“Pres. Erdogan was not informed that what he ill-recited in Baku refers to the forcible separation of areas north of Aras from Iranian motherland[.] Didn’t he realize that he was undermining the sovereignty of the Republic of Azerbaijan? NO ONE can talk about OUR beloved Azerbaijan”
North Aras, a province in northern Iran that borders Azerbaijan, is populated by ethnic Azeris. An estimated 18 million Azeris live in Iran, making the group the second largest ethnic group in the country.
The poem recited by President Erdoğan chronicles the separation and the division of the Azeri people in the region at the turn of the century, when Russia and Iran were vying for power in the Caucuses.
Lines from the poem recited by President Erdoğan include: “They separated the Aras River and filled it with rocks and rods. I will not be separated from you. They have separated us forcibly.”
The Iranian foreign ministry summoned the Turkish ambassador in Tehran over President Erdoğan’s recital, demanding an explanation over the president’s “interventionist and unacceptable remarks.” 
In a statement, the Iranian foreign ministry said:
“The Turkish ambassador was informed that the era of territorial claims and expansionist empires is over. Iran does not allow anyone to meddle in its territorial integrity.” 
Azerbaijan is one of Turkey’s strongest allies in the region and is considered to be a brother nation by Turkey, as the two nations are from the same ethnic group and speak the same Turkish language.
Under the motto ‘One Nation Two States’, Turkey has supported Azerbaijan in recent years both financially and militarily, investing in the country and providing it with top-tier military hardware, including its formidable Bayraktar TB2 drones.
Azerbaijan on its behalf has sold oil to Turkey, and the two countries together with Georgia have constructed a natural gas and oil pipeline that runs through Azerbaijan, Georgia, and Turkey, where it is then sold to markets in Europe and the US.
In the Baku victory parade, President Erdoğan declared:
“As long as Turkey and Azerbaijan work hand in glove, they will continue to overcome all difficulties and run from one success to the next.”
Turkey played an instrumental role in Azerbaijan’s military success in the recent Nagorno-Karabakh war. In the months prior to the war, Ankara conducted joint military exercises with Baku, training its soldiers and selling military hardware to its armed forces.
During the war, Turkish military specialists advised Azeri officers and commanders on how to effectively use the Bayraktar TB2 drones. After the victory, Turkey will further play an important role in the reconstruction of the territory recaptured by Azerbaijan.
Fighting broke out between Armenia and Azerbaijan in September. After 44 days of fighting, the Azeri military decimated Armenian defences with its drones, rapidly advancing into the occupied territories and capturing a number of towns and villages, including the second-largest city of Shusha.
A Russian-brokered ceasefire brought a halt to hostilities in November and marked an end to the war, cementing Azerbaijan’s victory. Under the terms of the ceasefire, Russian and Turkish peacekeeping troops will monitor the region.