The civil war in Syria in on track for an indefinite period of escalation following the collapse of a nationwide cease-fire on September 19. The truce negotiated by Russia and the US called for a cessation of hostilities to permit unimpeded humanitarian access to all besieged regions starting on September 12. However, the agreement was immediately and repeatedly violated, and collapsed when an attack on an aid convoy and a warehouse used by the Syrian Red Crescent in rural Aleppo, which the US blamed on Russia, prompted the UN humanitarian aid agency to suspend all activity in Syria.

Russia more recently agreed to a three-day truce to permit inhabitants of the rebel-held eastern section of Aleppo to flee, but reports indicate that very few people took advantage of the temporary calm, an indication that the rebels intend to carry on the fight. Aleppo is the opposition’s last urban stronghold, and were Assad to succeed in retaking it, the civil war would effectively be reduced to a rural insurgency. That said, rebels have for years dug fortifications and underground tunnels in Aleppo, a fact that makes it likely that physically retaking the city will be a long and bloody struggle.

The battle over Aleppo is likely to increase the prominence of jihadist factions among the armed rebels. The association of key groups with Al Qaeda has created a dilemma for the US, which is understandably reluctant to extend them substantive assistance or diplomatic support, a fact that Syria and Russia have exploited to their advantage.

More broadly, there does not appear to be any realistic basis on which to build a lasting peace. The incompatible demands of the warring factions and the competing interests of the foreign participants in the fight pose what look to be insurmountable obstacles to reaching a deal.

On a positive note, ISIL has lost control over key terrain across Syria (and Iraq) in recent months. Military assaults facilitated by an extensive bombing campaign conducted by US-led coalition forces have forced ISIL to move many fighters and much equipment to Libya. Even so, the total defeat of the group is highly unlikely. The Syrian army remains unable to confront simultaneously its many enemies, which poses an obstacle to retaking ISIL-held positions in central Syria. With ISIL’s ability to recruit new fighters ensuring that it remains a resilient force, the group will likely continue to be a source of risk in Syria for some time yet.