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US-backed Kurdish militias have lifted a siege on security forces in eastern Syria and the two sides exchanged prisoners, local sources said on Wednesday, in accordance with a Russian-brokered deal to contain hostilities in the area, which is at the crossroads of international rivalry in the 13-year civil war.
Fighting over the past week between the Kurdish-led Syrian Democratic Forces (SDF) and Arab tribal forces supported by Iran and Damascus threatened to undermine the presence of President Bashar Al Assad's forces in Qamishli and Hasakah – two urban centres in the east, where most of Syria's oil and wheat is produced.
After initial territorial gains, the Iran-backed fighters were pushed back and the Kurdish-dominated forces laid siege to Syrian security forces in the centre of the two cities. The presence of the state's security forces there is part of a more than a decade-long deal to share control with Kurdish militias over the east, a mixed area populated by Arabs and Kurds.
One source in the east connected with both sides said the prisoner exchange involved two dozen people, including Kurdish militia members and two Syrian army officers
“The regime did what the Russians told it to do, and the Kurds cannot afford to anger Moscow,” the source said.
The US, which finances the Kurdish militias, under the SDF and other armed organisations, has been on the sidelines as Russian officers brokered the deal.
Kurdish armed presence in the east was bolstered by co-operation with Damascus after the 2011 revolt against Mr Assad.
North-east Syria's ruling Democratic Party Union (PYD), a branch of the Kurdistan Workers Party (PKK) outlawed in Turkey, helped security forces crush demonstrations demanding Mr Assad's removal in the east. Between 2011 and 2012, the two sides started splitting control of the east, enabling the security forces to crush the mainly Arab Sunni revolt.
The Kurdish People Protection Units (YPG) emerged as a powerful armed group during the civil war and despite receiving support from the US, it has kept channels open with the Syrian regime, Russia and Iran as a buffer to Turkish incursions.
Wael Olwan, senior research fellow at the Jusoor Information Centre in Istanbul, argues that the deal brokered by Russia also benefits the US, whose troops have come under repeated attack by Iran-backed militia groups over the war in Gaza.
The attacks have increased since Iran vowed to retaliate against Israel, who it accused of the assassination of Hamas leader Ismail Haniyeh in Tehran on July 31.
Mr Olwan said that Moscow is “flexing its muscle” in the US's sphere of influence in Syria.
“The Russians don't miss an opportunity to present themselves as a mediator between the local players in the Syrian conflict, and show that they can guarantee the interests of even the outside players,” Mr Olwan told The National.
Iran has carved out a strategic supply corridor, along the Euphrates river valley, to Hezbollah in Lebanon, starting form the city of Al Bukamal near Syria's border with Iraq.
Syria's oil production fell sharply during the civil war from 300,000 barrels per day (bpd) in 2010, the last year before the revolt, to current estimations of 100,000 bpd.
Proceeds from the oil output, estimated at between $50 million and $100 million per month, mainly go to the Kurdish militias.