Major clashes broke out on January 16 in the northeastern Syrian city of Hasakah between fighters loyal to President Bashar al-Assad and the Kurdish militia known as the People’s Protection Units, or YPG. The fighting shatters a long-standing local truce between the Assad regime and the YPG, who had teamed up to confront the Sunni extremist group known as the Islamic State, which controls much of the countryside around Hasakah.

By Hasakah standards, the past week’s fighting has been severe. The YPG has accused the government of using cluster bombs and claims to have killed dozens of soldiers. The violence is also, unsurprisingly, taking on the contours of an ethnic dispute, with pro-YPG Kurds fighting against pro-regime Arabs. The Syriac Christian minority and its so-called Sutoro forces have tried to stay neutral, but their areas have been hit by grenades and attacks on Hasakah’s Assyrian Cathedral.

A divided Arab tribal community

The situation in Hasakah is peculiar. The city and the wider region is divided between Kurds and Arabs on the one hand, and internally among Arab tribes and villages, on the other. There are also significant Christian groups in the city, including Syriacs and Armenians.

The YPG has established a virtual monopoly of force among the Kurds. Most Christians seem to have remained on the government side, although some back the YPG. The Arab political landscape, however, is deeply divided. The two main contenders for influence among the area’s Sunni Arabs are the Islamic State and the government of Assad—himself an Alawite, like the hard core of his army, although his regime is a mélange of different religious groups. They are mortal enemies, yet in the Hasakah gGovernorate they find themselves in the awkward situation of both having to appeal to the same pool of Sunni Arab tribes. The regime holds sway in Arab areas of Hasakah city itself while the Islamic State dominates the Arab countryside.

The major tribal groups of the area—such as Baggara, Shammar, and Jabbour—are vast lineages stretching over several countries and not, as some political commentary would lead one to believe, functioning social units. Like in many other areas of rural Syria, loyalties instead tend to be patterned locally on family, subclan, and village lines, albeit with reference to the larger tribe. Clan rivalries can also be hard to distinguish from regional, political, and socioeconomic divides that would exist independently of any tribal sentiment. War has, of course, added its own complexities.

A mass of more or less well-armed clan groups, neighborhood militias, criminal gangs, and unemployed youth make up a fluid manpower reserve that political leaders seek to attract to their side with promises of a fixed salary or threats of force. The Islamic State is known to coopt opportunistic or defeated militias, in Iraq as well as in Syria. In Assad’s case, locals may be recruited into several pro-regime militias that exist in Hasakah, including the ruling party’s Baath Battalions, various groups run by the intelligence services, and the so-called National Defense Forces (NDF). Over time, there has been a fair amount of side switching among the Arab groups, with fighters passing through various regime or rebel militias in search of stronger allies, more secure defensive arrangements, or better pay.

Since summer 2014, things in Hasakah have changed a bit. Feeling under threat from the growing power of the Islamic State, the YPG and its police forces, known as the Asayish, opted to collaborate more closely with Assad’s army and the Arab militias to root out the jihadis. The city then remained divided through a system of checkpoints delineating the territory of each group, with agreements to secure the passage across town of aid convoys, local goods, and trade. It was a tense modus vivendi rather than a real alliance, but it more or less worked—until now.

Ruptured relations

Why now? Many reports indicate that the clashes began with a dispute over the placement of checkpoints and guards—both sides describe the other as the initial aggressor. The initial fighting was against a recently created Arab tribal militia known as al-Maghawir, or the Commandos, although the regular Syrian Arab army is now deeply involved, too.

It is possible that this was simply a turf war that got out of hand. But it is also possible that these early clashes or the ensuing escalation had a political motive.

Some point to Kurdish anger over the recently leaked minutes from a Baath Party meeting in November, where Assad reportedly ruled out autonomy or constitutional recognition for the Kurds in Syria, as a factor behind the rising tension. Some opposition supporters suggest that the YPG’s unofficial political wing, the Democratic Union Party (PYD), might be looking to polish its lackluster opposition credentials in time for peace talks in Moscow, if they happen.

Others see this in the context of the YPG’s flirtation with the West after the rise of the Islamic State this past summer. The U.S. Air Force is now acting as the Kurdish air force in the skies over Kobane and the U.S. military seems to coordinate closely with the YPG, a group that it had until recently refused to deal with. According to this argument, the YPG is trying to decrease its involvement with the regime and to demonstrate its political independence to still-skeptical Western policymakers, or it is simply using its improved position to put pressure on the army and extract new concessions.

An Iranian role?

Interestingly, the PYD’s European section has issued a harshly worded statement about the fighting, which jointly condemns “the Syrian and Iranian regimes” as “occupiers” and assigns a large share of the blame to Iran. The Shia government in Tehran is accused of “giving support and advice to the Syrian regime in order to sow sedition and subversion in Hasakah city and it has thus created a sort of communal confrontation between the Kurdish, Arab and Syriac communities.” According to the PYD-Europe statement, “the Iranian regime clearly had a hand in [starting the Hasakah violence] both in terms of incitement and execution.” Unfortunately, there’s no more detailed explanation of what exactly Iran has been doing in Hasakah of late.

However, it is widely understood that the Iranian government is a primary funder and organizer of NDF militias in many areas of Syria. And sure enough, the Commandos force—which was the first Arab group to drift into conflict with the YPG—has been accused of operating under Iranian patronage ever since its creation in December 2014.

Activists in Hasakah say that the Commandos are being recruited from local Sunni Arab tribes and other regime militias, such as the NDF, that already had tribal support. The Commandos’ formation should be seen in the context of government attempts to drag the Hasakah tribes over to its side in the war. It was allegedly preceded by the summoning, in early November, of 24 tribal sheikhs from northeast Syria to Damascus. The central figure in this process is said to have been Mohammed al-Fares, a sheikh of the Tai tribe and former member of the Syrian Parliament, whose clansmen in the Qamishli area have long functioned as a regime proxy.

Out of this gathering of tribal sheikhs and strongmen came the Commandos, a tribal militia now apparently being trained at a location south of Qamishli. Activists say that the training is overseen by a man known to them only as “al-Hajj Majed,” who is a member of Hezbollah, the Lebanese Shia militia that serves as Iran’s main proxy in Lebanon and Syria.

If it’s true that the Commandos are funded by Iran—which is perfectly plausible—that answers the question of why the PYD chose to lash out at the Iranian regime.

Rising Arab-Kurdish tension

With or without Iranian involvement, however, the Syrian government’s attempt to farm out security responsibilities to Arab tribal leaders and Baathists in Hasakah has raised tensions with the YPG. The Kurds in Hasakah have historically suffered at the hands of some of these groups, not to mention the anti-Kurdish policies of the Baath Party itself. The YPG can hardly feel at ease with a strategy that essentially consists of the Baath Party—and Iran, it seems—handing out guns to their traditional rivals. Indeed, one PYD source explicitly says the clashes began “following Bashar al-Assad’s comments against the Kurds and the creation of the regime’s Commandos militia.”

Kurdish-Arab clashes in Syria’s civil war have a history of flaring up violently and then dying down with little fanfare, including in Hasakah. But if the fighting continues, it may have a serious impact on the military balance in the city and the surrounding countryside.

The regime’s new recruitment drive among Arab tribes may help bolster its standing and compensate for its manpower problems, but maybe that’s exactly what the YPG is trying to prevent, fearful of the military balance turning against it. If the tacit YPG-regime alliance in Hasakah breaks down permanently, this would undoubtedly weaken the front against the Islamic State, which is waiting in the wings for an opportunity to pounce. But to stop the conflict in Hasakah, a new Arab-Kurdish equilibrium will have to be found.