Summary account by Marilyn Stern, Middle East Forum Communications Coordinator.
The fall of Aleppo was a turning point in the Syrian civil war. In an impressive feat, the Russian-backed Syrian army dealt a crushing blow to the rebel forces, driving many of them to entertain a compromise with the Assad regime.
This by no means implies that the war's end is anywhere in sight. With the regime in possession of merely one third of Syria's territory (and two thirds of the population), it now needs to gain control of the northwestern province of Idlib, with its 50,000-strong mainly Islamist rebels, in order to consolidate its Aleppo gains and to establish a sustainable land corridor to the Alawite region along the Mediterranean coast.
No less important, the Kurds seem determined to follow up the summer 2016 occupation of Manbij by seizing the strategically-located town of al-Bab, so as to establish contiguity between the Kurdish areas of Afrin and Kobane. This, however, will be anathema not only to the Assad regime but also to Ankara, which is fiercely opposed to Kurdish unification and which launched an armed incursion into Syria, with Moscow's tacit approval, to prevent this eventuality. Should the Turks respond to the fall of al-Bab by attacking the Kurds, this will greatly complicate Washington's hopes for a Kurdish offensive against the Islamic State's capital of Raqqa.
Bashar and Asmaa al-Assad have much to celebrate after the fall of Aleppo.
But even if the Raqqa offensive were to materialize, it is unlikely that Moscow and Tehran would allow eastern Syria to fall under the sway of the Western-Gulf-propped rebels (or to remain under ISIS control for that matter). For one thing, given this area's vast natural resources (notably oil, gas, wheat, and cotton), it is certain to play a crucial role in Syria's economic reconstruction. For another, Sunni control of eastern Syria would disrupt the territorial contiguity of the Shiite crescent - from Iran to Lebanon - that Tehran has been busy creating for some time.
As things are, while the internal Syrian opposition appears to have all but crumbled after the fall of Aleppo, the regime still confronts an uphill struggle. Though it looks likely to reassert its authority over western Syria with the support of its Russian and Iranian patrons (apart, perhaps, from a small Turkish enclave in northwestern Syria), the situation in the Kurdish areas and in eastern Syria seems much less promising. Yet if the limited and indirect Russian-American cooperation against ISIS's recent Deir az-Zour offensive is something to go by, it is clear that only when the two superpowers put aside their differences and pull together their military and diplomatic resources can the Islamic State be defeated and the Syrian civil war ended. Given the present international circumstances, this may be a matter of years rather than months.