Common front, diverging interests
The Tehran Summit strengthened relations among Turkey, Russia and Iran, confirming the shared intent to counter US foreign policy in the Middle East, starting with the ceasefire in Idlib, which could mean the end of Islamic State's (ISIS) control over the last enclave in Syria

Last Friday, the Presidents of Turkey, Recep Tayyip Erdogan, Iran, Hassan Rouhani, and Russia, Vladimir Putin, met to discuss the future of the Idlib Province in Syria. The three leaders had met last April in Ankara, facilitating trade among the three countries and accelerating the implementation of the Turkish Stream. On the eve of the summit, the United States' president Donald Trump had warned Syrian President Bashar al-Assad that any massacre in Idlib, the last Islamic State (ISIS) enclave in Syria, would not be tolerated. At the final press conference, the three leaders expressed their desire to eliminate Isis, the al-Nusra front and the other groups connected with al-Qaeda. Furthermore, the summit's final communique invited the United Nations and the International community to send humanitarian aid to Syria and take part in the country's reconstruction.

Still divided on the future of Idlib

The three leaders appeared divided on many key issues. In addition to the criticism of the US strategies in Syria, Russia, Iran and Turkey claimed to be close to the Syrian Democratic Forces (SDF), a coalition that includes Kurds and Arab militias.

The Turkish president proposed to postpone the offensive on Idlib or limit it to Hayat Tahrir al-Sham (HTS), a group linked to al-Qaeda. One week before the Tehran summit, the Turkish authorities had labeled HTS a terror organization, in line with the position of the United Nations and the United States. HTS controls 60% of Idlib. The Turkish authorities supported the National Liberation Front (NLF), close to the Syrian Free Army (ELS), instead. In the case of an offensive, the Turkish authorities could favor moving refugees to the Turkish-controlled territories in Northern Syria. Part of the refugees could be resettled in the Kurdish enclave of Afrin, currently under total Turkish control after last January's Olive Branch operation.

Some fighters from the Kurdish People Protection Units (YPG) could participate in the Idlib offensive, together with Assad's regular forces. Any strengthening of the Kurd combatants in Northern Syria would be a key worry for Erdogan, who is fragmenting Kurdish territories in Syria. Turkey managed to obtain control of a vast region in the north of Idlib thanks to the laissez-faire policies of Russia and Iran. In 2016, Turkey obtained a green light for the offensive against Isis in Jarablus and al-Bab, by allowing control of the pro-Russian rebels in East Aleppo. In 2017, Turkey pushed the Islamic rebels to Idlib, obtaining the go-ahead from Moscow to dislodge Kurdish fighters from Afrin. Erdogan admitted the strategic interest the city plays for Turkish interests in Syria: "Idlib is important not just for the future of Syria, but also for our national security". On the other hand, Russian President Putin claimed to be skeptical about any cease fire. "I cannot guarantee that terrorists from Jabhat al-Nusra or Islamic State will stop shooting", he said. Finally, according to Iran's President Hassan Rouhani, Damascus should take back control of the entire territory and the United States should finally leave the country.

Iran and the nuclear treaty

Iran is facing new US sanctions. On 6 August, the US measures began to apply again, after Trump's decision to decertify Iran's compliance with the agreement reached in Vienna in 2015. The first sanctions applied to dollar purchases from Iran's government, trade in gold and precious metals, direct or indirect sales, supply or transfer to and from Iran of graphite, crude and semi-finished metals like aluminum, steel, carbon and software for industrial processes, transactions implying sale or purchase of Iranian rials, keeping accounts held in rials outside Iran, purchase, subscription or facilitating the issue of Iran's sovereign debt.

Secondary sanctions extend to any country that continues to have economic and trade relations with Iran. The USA reserve to restrict economic relations with businesses from such countries, or ban them altogether. This extension of sanctions to European countries, in particular, is causing  firms - especially, but not exclusively French ones - to abandon any project for foreign investments in Iran. Even though the United States never did eliminate sanctions against Tehran, as they promised with the implementation of the agreement in January 2016, these new measures could provoke the end of the Vienna Agreement, despite the efforts made by the EU High Commissioner for Foreign Policy, Federica Mogherini, to keep the agreement alive.