AMMAN: A group of 15 military factions in Idlib and Aleppo provinces joined the US-supported Syrian Democratic Forces coalition on Monday amidst ongoing uncertainty about the potential for the combined forces to become significant actors in Syria’s north.

The 15 factions, both Arab, FSA brigades and Kurdish forces, declared themselves “fully prepared to fight in Aleppo and Idlib under the banner of the Syrian Democratic Forces” in a video announcement posted online by Jaish al-Thuwar, an FSA rebel coalition that is the most prominent Arab group of the 15 newest members.

The move came in response to “terrorism represented by the Islamic State, its sister [organizations] and the criminal Baath regime,” the announcement said.

In addition to Jaish al-Thuwar, the 15 groups in Aleppo and Idlib that reportedly joined the SDF Monday also include 11 minor Arab opposition factions, YPG/YPJ forces, and Jabhat al-Akrad, a previously FSA-affiliated Kurdish group.

Aleppo, Idlib factions joined the SDF on Monday. Photo courtesy of Jaish al-Thuwar.

The SDF is a multiethnic anti-IS alliance formed in northeastern Al-Hasakah province more than a month ago to battle the Islamic State. The coalition has made significant gains there since. Though primarily made up of Kurdish People’s Protection Units (YPG), SDF forces also include Arab tribal militias and FSA rebel factions.

References to “IS and its sisters” [sympathetic organizations] in Monday’s announcement appear to indicate that the new SDF affiliates will not limit their fighting efforts to the Islamic State alone. While IS has been the sole focus of SDF operations in Al-Hasakah, there is no official Islamic State presence in Idlib, which has been controlled by Al-Qaeda affiliate Jabhat a-Nusra, Ahrar a-Sham and other Islamist rebel forces fighting in the Victory Army coalition since this past June.

While it was not clear who the “sisters” of the Islamic State are, one activist on the ground points to enmity between Jabhat a-Nusra and some members of the SDF.

“We in the SDF and Jaish al-Thuwar are against the project of Al-Qaeda in Syria, which is represented by Jabhat a-Nusra,” said Idlib-based journalist Khaled al-Zino, who works with Jaish al-Thuwar.

Al-Zino declined to comment on the number of fighters in the new SDF forces in Idlib and Aleppo or the location of future operations.

In Aleppo, any brigades joining the SDF risk alienating and possibly provoking Nusra, says a journalist based in Aleppo city.

“If FSA factions in Aleppo city and its countryside work with the SDF, then Nusra will attack them,” Mustafa Sultan said.

Despite the risk of antagonizing Nusra, joining the SDF connects these fighters with an alliance that receives support in the form of international coalition airstrikes and US shipments of weapons and ammunition, most recently this past Saturday.

Can they have an impact?

Several activists in both Idlib and Aleppo told Syria Direct on Tuesday that they have not heard of several of the military factions that joined the SDF on Monday. Others appear to be marginal groups keeping mostly to Kurdish-controlled areas in the north in order to avoid conflict with stronger Islamist groups.

“The factions mentioned in the announcement are generally not present in Aleppo city or its countryside,” Aleppo-based journalist Sultan told Syria Direct Tuesday, “but rather in the Kurdish areas such as Kobani and Afrin” near the Turkish border in the north of the province. Three other Aleppo journalists corroborated Sultan’s account to Syria Direct on Tuesday.

In Idlib city and the surrounding countryside, five activists who spoke with Syria Direct on Tuesday said that they had never heard of several of the factions listed as being from Idlib in Monday’s announcement.

Khaled al-Zino, the journalist working with Jaish al-Thuwar, says that these Idlib brigades are in fact on the ground.

The new SDF members “have a presence in Idlib,” al-Zino said, “but keep a low profile for security reasons, as Jabhat a-Nusra controls a wide swath of territory.”

One of the FSA brigades named in the SDF announcement Monday, US-trained Division 30, denied having joined the alliance in a statement published online on Tuesday.

“We are not and will not be one of the groups making up these forces,” the brigade’s leadership wrote.