Hassan Hassan writes: A week after ISIL was reportedly expelled from its last stronghold in Hasaka, it launched an assault in Tal Abyad in northern Raqqa in the early hours of Saturday.

The militant group clashed with Kurdish militias affiliated to the People’s Protection Units (YPG), who drove ISIL from this border city in June last year. The attack on Saturday was ISIL’s second infiltration of the city since its defeat there.

During the clashes, ISIL fighters reportedly stormed the house of a tribal sheikh from Deir Ezzor living in Tal Abyad and beheaded him. Khaled Dahham Al Bashir – from the Baggara tribal confederation, one of the largest in Syria – was said to have been working with the YPG as part of the tribal component in the Syrian Democratic Forces, and was therefore an obvious target for ISIL. The ISIL assault on several different locations seemed carefully planned with specific targets.

Of particular significance was the fact that the YPG had to immediately call in US air strikes to repel the attack. The episode reveals a fault line in the way that the United States, the main backer of the YPG, fights ISIL in Syria.

The YPG’s victories against ISIL – in Kobani, Tal Abyad and southern Hasaka – were made possible largely because of intensive US firepower. According to military sources, the YPG lacks the capacity to defeat ISIL without close US air support. One source said that American air strikes account for “more than 90 per cent” of the ISIL defeats in those battles.

This is important if one contrasts the YPG with other forces in northern Syria that have defeated ISIL or repulsed its assaults for more than two years without any air support. Those forces would typically be fighting on two fronts at the same time. Rebel forces in Idlib, for instance, have kept the province free from ISIL despite repeated attempts to infiltrate it since 2014 – including at the peak of ISIL’s strength and morale after it defeated the Iraqi army in Mosul. [Continue reading…]