Presidents of Iran, Russia and Turkey will meet in Tehran to discuss the war in Syria, with all eyes on a possible military offensive to retake the last rebel-held bastion of Idlib.
The summit on Friday, the third between Iranian President Hassan Rouhani, Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan, may determine whether diplomacy halts any military action.
The three leaders are expected to try to forge an agreement to prevent what the UN has warned could be a catastrophic offensive by Syrian President Bashar al-Assad’s forces to recapture Idlib province, which borders Turkey and which harbors tens of thousands of the last armed rebels fighting Assad.
The Syrian government has vowed to retake Idlib, the last opposition stronghold that has been controlled by the rebels since 2015.
Northwestern Idlib province and surrounding areas are home to about three million people – nearly half of them are civilians that have been displaced from other parts of Syria.
Iran, Russia and Turkey all have their own competing interests over Syria. Russia and Iran are major allies of the Syrian government, while Ankara backs the rebels.
Turkey, which borders Idlib, criticised Russian air attacks on the province days before the summit and has warned of a humanitarian catastrophe in the event of an offensive.
Syrian government troops and their allies have amassed troops near the Idlib countryside in preparation for a final assault.
An estimated 10,000 Al-Qaeda-linked fighters are among those rebels, and the province is also home to about 3 million civilians — nearly half of them displaced from other parts of Syria.
Russia and Iran are both allies of the Syrian government, which has set its sights on retaking Idlib in what it sees as the next critical step to clinching a military victory in the seven-year civil war that has killed more than 400,000 people and displaced millions.
For Syria and Russia, the province is also strategically important because it borders Latakia province, Assad’s main stronghold and the site of Russia’s biggest airbase in the country.
Turkey backs many of the rebel groups in the province, although it recently moved toward its negotiating partners in declaring that the dominant rebel group, the Al-Qaeda affiliate Hayat Tahrir al-Sham, formerly known as the Al-Nusra Front, is a “terrorist organization” that should be eliminated.
Russian officials have said such “terrorist” groups should be “liquidated,” but the Russian military has also said it is seeking to separate out extremist fighters from other rebel groups supported by Turkey.
While Syria has been massing thousands of troops in preparation for an assault, Russia, which has provided air support to the Syrian Army since 2015, has also made a big show of force by moving 10 warships and two submarines off the coast of Syria.