REYHANLI AND GAZIENTEP, TURKEY — Gains by Jabhat al-Nusra, an Al Qaeda affiliate, have forced two major US-backed rebel groups to disband at a time when Washington needs solid partners to counter the influence of jihadists in Syria.

Al Nusra, the main jihadist rival to the self-declared Islamic State, delivered a deathblow over the weekend to Harakat Hazzm, seizing the moderate rebels’ headquarters in Aleppo Province. It also took its remaining weapons, including dozens of US-supplied TOW anti-tank missiles, according to images the group disseminated.

Hazzm’s defeat is a setback for Washington, which has struggled to create a coherent strategy that bolsters pro-Western groups among the opponents of Syrian President Bashar al-Assad. After careful vetting, the CIA had zeroed in on Hazzm as a movement worth arming and training in a covert program launched in 2014.

The moderate Hazzm, which once boasted 2,000 members, had regrouped in Aleppo Province after being routed from its base in Idlib Province by Al Nusra and its allies. It was one of the groups due to be trained by the US in Turkey under a recent agreement between Washington and Ankara.

“The full dissolution of Hazzm over the weekend is a pretty big success for Jabhat al-Nusra in its efforts to marginalize moderate rebels in northern Syria,” says Jennifer Cafarella of the Institute for the Study of War in Washington.

Al Nusra, says the analyst, wants to reduce the influence of moderate groups that could turn against it because of their dependence on the West. It also aspires to be the preeminent face of the revolution in Syria, a goal it has partially achieved by becoming a vital ally to most rebel groups fighting Assad.

Hazzm said it dissolved itself “to avoid bloodshed” and sent its surviving members to join Jabhat al-Shammiyya (Levant Front), a loose coalition of antigovernment forces in Aleppo.

The demise of Hazzm caps months of sparring that spanned two provinces along the border with Turkey. Activists in Aleppo City describe the mood as tense, with many expressing the fear that Al Nusra may turn its attention to other groups that are in the good graces of the United States, such as the Nureddine al-Zinki Brigades, one of the most important rebel factions in Aleppo.

“People fear there will be new fights,” says Aleppo-based activist Abu Amer. “Nusra, being Al Qaeda, has problems with anyone who sides with the US.”

Hazzm received no support

Al Nusra had previously knocked out the moderate Syrian Revolutionary Forces (SRF), the largest US-backed rebel faction, which it defeated in the fertile basin of Idlib in November. The US ally folded almost without a fight. Its leader, snubbed by locals and other rebel groups for corruption and smuggling, fled to Turkey.

“Al Qaeda aims to control the liberated areas of Syria and eliminate the Free Syrian Army so that it can establish an emirate,” said defeated SRF commander Jamal Maarouf in a December interview in the border town of Reyhanli.

Syrian activists issued a statement condemning the latest offensive against Hazzm, saying it distracted from the fight against the regime of President Assad and the extremist IS. They also accused Al Nusra of copying IS by using allegations of corruption as a pretext to attack rivals.

“This is the same pretext that Daesh [IS] used in its attacks against the rebels” in Raqqa, 135 signatories said.

In the end, however, none of the other Aleppo-based rebel groups were willing to stick their neck out for Hazzm. “Nusra has taken Base 46 and set up camp there. The situation is very tense at the moment. No one wants to interfere,” says Abdullah Baddawi, an activist in the city.

Base 46 is a strategic hilltop military base near the town of Atarab in Aleppo Province.

Al Nusra in search of an ’emirate’ Both the Aleppo and Idlib clashes were the direct outcome of vendetta killings and kidnappings between the groups.

Rita Katz, founder of SITE Intelligence Group, suggests the pro-Western groups could have had their reasons to wage such a campaign of kidnappings and assassinations against Al Nusra, which is designated by the United States as a terrorist organization and has been targeted by US-led airstrikes.

“The more you observe the fighting across Syria, a complex web of alliances starts to emerge,” says Ms. Katz. “Al Nusra Front can be seen all across this web, maintaining strategic alliances with Islamist and secular groups alike.”

The two moderate groups, she adds, instigated the clashes with the Nusra Front “possibly by orders from the US,” which funded, trained, and equipped them with weapons. Hazzm was far too small to truly threaten Al Nusra, which has wide support across the country, she notes.

Both Katz and Ms. Cafarella concur that Al Nusra would not enter a fight that hurts the overall effort against the Assad regime. Their No. 1 priority, they say, is to nurture the support of the local population and lay the foundations of an “emirate,” a territory loyal to Al Qaeda in which Islamic law is enforced. That project is well underway in Idlib.

Different posture in the south

Personalities have also played a large role determining Al Nusra’s relationship to other rebels group. In the north, Al Nusra saw a low-risk opportunity to eliminate rivals who had affronted them. In the south, it maintains a collaborative relationship with others, including the Washington-endorsed Southern Front.

“Jabhat al-Nusra is very sensitive to anything related to the local population. They need their support. They know that. They are not ISIS,” says Katz. She predicts the group will mostly replicate the strategy of the Somali-based Al-Shabab militant Islamist group.

Cafarella ventures that there may be an “expansion of Jabhat al-Nusra action and aggression towards moderate” rebels in the areas of Rastan and Talbiseh, north of Homs City.

She says it is unlikely Al Nusra will pursue other groups in Aleppo given the strategic urgency of fighting the regime.

“There is a limit to how much Nusra can sideline other rebel groups,” she says. “That limit is the continued ability to defend against the regime.”

Photo Courtesy of AP Images

This post originally appeared in The Christian Science Monitor