After weeks of heavy fighting between the Russian-backed Syrian army and rebel groups in eastern Ghouta, the Syrian government has managed to bring over 90% of the strategic Damascus suburb under its control. The development comes as the result of a deal between Russia and the rebel groups, based on which the rebel groups agreed to evacuate the area and transfer their remaining forces to the rebel-held city of Idlib in the country’s northwest. Now, with the radical group Jaish al-Islam also reportedly beginning to leave its enclave in Douma, President Bashar al-Assad’s government is just one step away from its most significant victory after retaking Aleppo in December 2016.

Since the start of Operation Damascus Steel in eastern Ghouta in February, Russia began to actively support the regime both by providing air support for the Syrian army and starting to negotiate with the rebel groups over evacuation deals. At the diplomatic level, Moscow prevented the United Nations Security Council from passing a resolution that would have tied the Syrian government’s hands in fighting the militant groups.

However, Assad’s other main ally, Iran, refrained from any active involvement, preferring instead to leave the task to Moscow and Damascus. Although Iran has always declared that its military involvement in Syria is of an advisory nature, this time there were no reports of the presence of Iranian military commanders in the Syrian war room nor even pro-Iran fighters in eastern Ghouta. Iran’s only direct political position on the issue came from Deputy Foreign Minister Abbas Araghchi, who on Feb. 22 expressed the Islamic Republic’s concern over the situation in the area, calling for a political solution to the conflict.

Why is Iran now breaking its seven-year tradition of supporting Damascus against the rebel and terrorist groups? Are we witnessing a change in Iran’s Syrian strategy or merely a tactical move aimed at preserving certain goals? To answer these questions, several separate but related factors should be taken into account.