A pro-YPG Kurdish activist from Ras al-Ain, who wished to remain anonymous, told Al-Monitor via phone that it is possible that “there was not enough popular support for the regime to set up an NDA branch in Ras al-Ain, [so] it chose a limited option under the banner of the YPG."

"In Ras al-Ain, people still voice their opposition to the recruitment of supporters of the regime by the YPG," Nasser al-Khalil, a Euro-Mediterranean Human Rights Network researcher from Ras al-Ain who recently moved to Turkey, told Al-Monitor in a phone interview.

On Dec. 24, the press agency of the pro-Barzani Yekiti Syrian Kurdish Party (PYKS) denounced the merging of the Abu Jabal Brigade with the YPG in the area of Tel Hamis, southeast of Qamishli. The Arab-populated town of Tel Hamis is one of the few rebel strongholds left in the northern Hassakeh province. The brigade's commander, Yusuf al-Abdullah from the Arab Sharabia tribe, is a member of the Popular Army, otherwise known as National Defense Army (NDA), a pro-regime militia whose local branch is headed by Mohammad Faris from the Tayy tribe.

On Nov. 2, Rihab News reported that the Arab Brigade of the Free Patriots joined the YPG in Ras al-Ain, northwest of Hassakeh. The brigade's commander Hawas Jammo and another of its fighters, Osama Jasim al-Karot, are known to be regime collaborators who attacked anti-regime demonstrators in 2012, according to the Rihab News report and local Kurdish activists and journalists who spoke with Al-Monitor.

According to local Arab and Kurdish sources, the Democratic Union Party (PYD) has been enlisting Arab loyalists in its armed wing, the People's Protection Units (YPG), in a bid to boost its credibility among Arabs and join efforts with the Syrian regime on the battleground against the opposition. This military strategy was reportedly accompanied by some intense consultations held in Qamishli between the regime and its Arab allies immediately before the formation of the PYD-led autonomous government on Jan. 21.

Ahmad Judan al-Ghannam, a pro-opposition Arab activist from Tel Hamis, told Al-Monitor in a Skype interview that Abdullah’s son was killed by rebels when they seized Tel Hamis in 2012.

“His brigade is made up of 200 shabbiha [Syrian government-backed militia], who had launched attacks on the town in July 2013," he said.

On Dec. 23, in an interview with the press agency Adar Press, Abdullah described the rebels who took Tel Hamis on Feb. 21, 2012, as "foreign-backed gangs of mercenaries."

"The recruitment of Arabs serves to justify the YPG's presence in the Arab regions," said Ali al-Asi, an Istanbul-based opposition activist originally from Yaroubia with close ties to the presidency of the National Coalition for Syrian Revolutionary and Opposition Forces, in a phone interview with Al-Monitor.

A Kurdish-Arab entente remains paramount to the stability of any transitional administration, particularly in a region riven by land disputes between the two communities. The Assad regime, in its backing of the PYD, could bridge differences by setting up a unified front of its Arab and Kurdish allies against the Syrian opposition .

The mediation of Damascus in securing Arab support is at the core of the long-term political ambitions of the PYD, as much as its diplomatic efforts — to date unsuccessful — to shrink Turkish support for the Syrian Arab rebels.

The new alliance is crucial to both the regime and the PYD. It is not short term; it is necessary to subdue the Arab tribes and keep them loyal to the regime, even under a Kurdish local administration.

According to both Kurdish and pro-regime sources, on Jan. 2 — right after the alliance between Abdullah and the YPG was announced — the YPG and the NDA took part in a failed attempt to reconquer Tel Hamis. Despite this, the Kurdish militia denied any cooperation with the government, in an attempt to defend its reputation as a revolutionary force, while at the same time comparing its recruitment of pro-regime Arabs to the presence of defectors from the government in the opposition Free Syrian Army (FSA).

"The fact that these local Arabs had some ties with the regime doesn't qualify them as shabbiha. Even FSA officials used to work at the highest ranks of the regime's institutions," YPG spokesman Redur Khalil said in a written interview.

However, what went unnoticed was the coincidence between the birth of these YPG Arab brigades and the three visits paid by regime officials to Qamishli over the two months before the declaration of the PYD-led transitional government. On Nov. 30, 2013, it was the turn of the minister of defense, Gen. Fahd Jassim al-Freij. On Dec. 9, there was another delegation headed by the governor of Hassakeh, Mohammad al-Za'al. On Jan. 20, one day before the formation of the PYD's transitional cabinet, Qamishli received another visit by the governor. This time, the meeting was not announced in the media, possibly due to the alleged presence of the Syrian security chief Ali Mamluk.

Local activists and opposition figures believe that Mamluk's visit was aimed at reassuring the Arab tribes about the PYD's agenda.

"The army was deployed in the main areas of Qamishli for the arrival of a high security official from Damascus, and we learned it was Ali Mamluk from a source inside the airport," a Kurdish activist from Qamishli, who wished to remain anonymous, told Al-Monitor in a written interview.

In July 2013, in a sign of unease among local Arabs, Mohammad Faris from the Tayy tribe had announced his opposition to a Kurdish government. Tribal concerns over the PYD’s push for autonomy prompted the regime to hold consultative talks and assuage Arab concerns.

"Ali Mamluk, Gov. Za'al and the secretary of the Baath Party's branch in Hassakeh, Khalaf al-Muhasshim, met with Hassan al-Maslut from the Jabbur tribe, Abdul-Razzaq al-Tayy and my uncle Hussein al-Hajji from the Bani Sab'a tribe," Ghannam, the activist from Tel Hamis, told Al-Monitor.

The YPG declined to comment on this episode, but it did not deny the visit took place. "We don't have information on the governor's visit, but I don't rule out a meeting between the regime and the Arab tribes hostile to the autonomous government, as some chauvinist Baathist Arabs cannot digest the fact that Kurds have rights," the YPG's Khalil said.

Local observers noted how Kurdish forces realized the need to secure Arab tribal support against Islamist insurgents.

"The YPG needs the Arab clans to fight on its side against the Islamic State of Iraq and al-Sham (ISIS). Their recruitment resembles the Iraqi Sahwa militia in a similarly tribal context," Nasser al-Khalil, the Euro-Mediterranean Human Rights Network researcher said.

For the moment, the number of Arab brigades under the YPG is still few. "The YPG counts more than 300 Arab fighters," according to Khalil.

For the PYD administration, the regime remains the only key for the inclusion of selected military and political Arab figures. Such mediation is also in the interest of Damascus, as it will keep Arab tribes aloof from the opposition by rallying their temporary support for a compliant Kurdish administration.