ERBIL, IRAQ -- Syria's Kurds have mostly escaped prolonged bouts of direct conflict in the country's civil war, but with rebel units pushing east toward the resource-rich Kurdish heartland, Kurdish militias proliferating and calls for greater autonomy growing, this may not remain the case.
Last summer, the Democratic Union Party, known by its Kurdish-language acronym P.Y.D., seized control of many towns and villages in the Kurdish majority northeast. The group also holds territory in a few Aleppo neighborhoods and some towns around the city.
The P.Y.D. is the most powerful Kurdish faction in Syria and has a well trained militia. This is perhaps a product of its ties to the Kurdistan Workers' Party, or P.K.K., a guerrilla group that has been fighting for Kurdish autonomy in Turkey.
The leadership of the P.Y.D. plays down its ties to the P.K.K. But Syrian Kurds often use the names interchangeably, and P.Y.D. offices feature portraits of the imprisoned P.K.K. leader Abdullah Ocalan and Syrian P.K.K. guerrillas killed in fighting with Turkey.
Detractors of the P.Y.D. accuse it of working in collusion with the Syrian government. The party's leadership and supporters, who say they were struggling against the government to secure rights for Syria's two million-plus Kurds well before the uprising began in 2011, reject this allegation.
But in the complexities of Syria's civil war, friendships are not born of common enemies.
The P.Y.D.'s militant Kurdish nationalism, which puts ethnic identity before allegiance to Syria, and their goal of some form of autonomy has put them at odds with Syria's rebels. After decades of discriminatory policies against the Kurds under the Baath Party, the P.Y.D. is opposed to anybody but Kurds ruling their areas.
Last month, fighting flared in Ras al-Ain, which the Kurds call Serekaniye, as rebel units assaulted P.Y.D.-held areas. Dozens were killed in the fighting.
"Those groups attacking Serekaniye, we don't consider them as Free Syrian Army," said Saleh Muslim, the leader of the P.Y.D. Instead, he said the groups that attacked "are mainly just taking orders from the Turkish regime."
The Free Syrian Army "is a name, or a trademark, not registered to anybody," said Mr. Muslim. "So anybody can come from his home and get a hold of some weapons and say, 'I am Free Syrian Army."'
The push on Ras al-Ain, a town on the Turkish border about 300 kilometers, or 185 miles, northeast of Aleppo, could reflect a number of things: a rebel attempt to gain strategic territory, the lack of coordination among Free Syrian Army units, the spread of armed groups beyond the control of the Free Syrian Army, or the prodding of rebel groups by Turkey to confront the Kurds.
Mr. Muslim believes that Turkey, which is concerned that P.Y.D.-controlled areas along its borders could act as a base for P.K.K. attacks and has warned of intervention if it feels threatened, had something to do with the outbreak of fighting.
"I think it's a part of the larger plan by the Turkish regime," he said. "They want to disarm all people, to leave them without defense."
Beyond the strategic value offered by the northeast, with its access to long stretches of the Iraqi and Turkish borders, the area is home to the majority of Syria's oil. Before the conflict, oil exports earned Syria $4 billion per year.
The amount of oil that Syria could produce is negligible when compared with other exporters in the region, but with the economy shattered the oil fields are attractive real estate.
There are conflicting reports over who holds the main northeastern oil fields around the town of Rmeilan, though in late January a video appeared online purporting to show members of the P.Y.D.'s militia patrolling the smaller Gir Ziro field nearby.
Beyond the P.Y.D., the other notable political player in Syria's Kurdish areas is the Kurdish National Council, a coalition of 16 parties. The parties are mostly small and have differing views, though on the whole they are more amenable to working with the mainstream Syrian opposition, which the P.Y.D. rejects.
The Kurdish National Council was further fractured when four of its parties close to the leadership of Iraq's Kurdistan Regional Government formed a seemingly independently acting bloc in December.
"In terms of the relationship with the Syrian opposition and in terms of their demands, the formation of this subgroup is in fact a greater element of division within the Kurdish National Council," said Maria Fantappie, an analyst in Iraq with the International Crisis Group.
Mustafa Jumaa, who leads the Azadi Party, one of the factions in the Syrian Kurdish Democratic Union, said the alliance had been formed out of frustration with the inability of the Kurdish National Council to make decisions.
Members of the new bloc have started to field militias, with Mr. Jumaa saying the union has about 1,500 fighters in Syria and will ultimately take control of thousands more troops being trained by Kurdistan Regional Government forces, the Peshmerga, in Iraq.
Previously, the P.Y.D. was the only Kurdish group in Syria with a significant armed presence.
"We took this decision because we saw the future for Syria was getting worse and maybe we would be facing heavy clashes in Kurdish areas, so we have to be ready for that," Mr. Jumaa said. "The most important thing is that we do not want to fight our Kurdish brothers."
Given the sharp political divides, the introduction of militias could increase tensions and the possibility of intra-Kurdish fighting down the line.
Ms. Fantappie, the analyst, said the Syrian Kurdish fighters being trained in Iraq were "an important counterbalance to negotiate with the P.Y.D.," though she said she did not believe that the formation of more militias in the area would result in a fight.
Like others in his alliance, Mr. Jumaa holds a mostly favorable view of the mainstream Syrian opposition and the Free Syrian Army, which he referred to as "a national army for Syria."
But in a war rife with misgivings and uncertainties, Mr. Jumaa said his group was prepared for other outcomes.
"If the Free Syrian Army attacks our Kurdish area, our political opinion will change completely and we will be against them also," he said. "Even if we do not agree with the P.Y.D. on a lot of things, we have to defend and protect our area."
He added that if minorities were not guaranteed their rights by the opposition in a post-Assad Syria, there would be a "revolution within a revolution."
As sectarian and ethnic lines harden, many Syrian Kurds fear for the future and are especially concerned about what could happen if their areas fall under rebel control.
In the Iraqi town of Shariya, just outside of the city of Dohuk, Syrian Yazidi refugees, a minority within the Kurdish minority, have sought shelter with their co-religionists. Members of the Yazidi faith, which shows influences from a number of religions including Islam, Christianity and Zoroastrianism, have long been persecuted for their beliefs. The refugees in Iraq fled mostly out of fear of Arab Islamist fighting groups in Syria, particularly extremist elements like the Nusra Front.
A man who identified himself only as Ahmed left his hometown, Qastal Jindu, near Efrin, after an Islamist rebel unit attacked the village. "The P.K.K. defended the village," he said. "Without the P.K.K. we all would have been killed."
As he spoke in the sparse concrete room he was renting, his children attentively watched a movie depicting a past P.K.K. struggle against Turkey.
These fears have helped raise the popularity of the ultranationalistic Kurdish ideology of the P.Y.D., said Omar Hossino, a Syrian-American researcher in Washington. "They are getting a lot of recruits because people are afraid of Islamists," he said. "People are starting to move into ethno-sectarian militias to protect themselves."
This retreat to ethnic and sectarian identities in Syria could prove to make any future dialogue between different groups difficult. "It's one of the most dangerous consequences of the armed conflict," Ms. Fantappie said.
This article originally appeared in The New York Times.