By SETH J. FRANTZMAN

Before midnight on September 15th a Russian airstrike hit near where US-coalition supported Syrian Democratic Forces were operating east of the Euphrates river. According to a statement by the Combined Joint Task Force Operation Inherent Resolve, “At approximately 12:30 a.m. GMT Sept. 16, Russian forces struck a target east of the Euphrates River in Syria near Dayr Az Zawr, causing injuries to Coalition partner forces.”

This highlights just how close Russian-backed Syrian regime forces on the western bank of the Euphrates and the SDF, on the eastern side, are operating. In the last weeks the two forces have drawn closer as the Syrian army lifted a two and a half year siege of the city on September 5th. Days later the SDF slashed through ISIS lines and drove into the eastern part of the city, towards an industrial zone.

On September 15th the SDF said they would not permit the Syrian regime to cross the river. Reuters reported that Military council commander Ahmed Abu Khawla warned government forces and their militia allies against firing across the river. It had happened several times already. “Now we have 3 km between us and the eastern riverbank, once our forces reach the area, any shot fired into that area we will consider an attack on the military council…We have notified the regime and Russia that we are coming to the Euphrates riverbank, and they can see our forces advancing…We do not allow the regime or its militias to cross to the eastern riverbank.”

Those comments have been met with ire from Damascus. Press TV, which is close to the Iranian regime, which supports Assad, reported that the Syrian regime has threatened to fight the SDF. “Whether it’s the Syrian Democratic Forces (SDF), or Daesh or any illegitimate foreign force in the country… we will fight and work against them so our land is freed completely from any aggressor,” said Syrian regime spokeswoman Bouthaina Shaaban to al-Manar TV, a Hezbollah affiliated channel. That night the Russian airstrike next to SDF fighters took place.

According to the US-led coalition statement on September 16th: “Russian munitions impacted a location known to the Russians to contain Syrian Democratic Forces and Coalition advisors. Several SDF fighters were wounded and received medical care as a result of the strike.”  Most importantly it notes that “Multinational Coalition troops advising and assisting the SDF were present but not wounded as a result of the Russian strike.”

The US has constantly stressed that there is a de-confliction line of communiciations “open 24 hours” with the Russians. In an interview in August with me, the coalition discussed this mechanism around Deir Ez-Zor. The US has also struck ISIS targets west of the Euphrates as recently as late August. “We put our full efforts into preventing unnecessary escalation among forces that share ISIS as our common enemy,” said Coalition commander Lt. Gen. Paul E. Funk II, in the September 16th statement. The statement notes that Coalition forces and partners always retain the right of self-defense. In June the coalition downed a Syrian aircraft near Tabqah to defend SDF forces. After that altercation the Russians also threatened coalition aircraft.

In this recent case the Russians have denied targeting the SDF. According to the BBC “On Sunday Russian defence ministry spokesman Maj Gen Igor Konashenkov said Russian planes had only carried out carefully targeted strikes against IS in Deir al-Zour province.” The statement goes on to note: “To avoid unnecessary escalation, the commanders of Russian forces in Syria used an existing communications channel to inform our American partners in good time,” Gen Konashenkov said. “Why would we bomb them,” The National reported Konashenkov asking.

Russia Today, which is close to the Russian government provided further reports. “To avoid unnecessary escalation, the command of the Russian troops in Syria revealed the boundaries of the military operation in Deir ez-Zor to the American partners through the existing communication channel,” the Russian Defense Ministry said in a statement on September 17th.  “Within the framework of this operation, the fighters, armored vehicles, and objects of terrorists are being destroyed on both western and eastern banks of the Euphrates. At the same time, the Russian Air Force makes pinpoint strikes only on reconnaissance targets confirmed by several channels in IS-controlled areas,” Konashenkov said. The same report included claims that the US was “airlifting terrorist assets” out of Deir ez-Zor. This has become part of a pattern of pro-regime and Iranian media recent claims accusing the US of “airlifting” ISIS members.

Source ISIS live map September 15th

Three kilometers

What is most important is that US-backed forces and Russian-backed forces are now almost within sight of eachother. Before the war it was only a ten minute drive from where the regime sits on the banks of the river and where the SDF is. A small buffer of ISIS terriotry divides the two forces, but for all intents and purposes they are now rubbing up against one another. The map reveals just how close it is.

The Russian strike, coming on the heels of warnings against the SDF and SDF threats against the regime not to cross, seems designed to keep the SDF out of the eastern suburbs of the city. In other areas the regime and SDF have met amicably. For instance in Aleppo the regime areas coexist with the People’s Protection Units (YPG), which is a key part of the SDF. Russian forces have also been spotted in the YPG controlled canton of Afrin which shares a small land corridor with the regime.

The Manbij agreement, map at ISIS live map

Most interesting, after Turkey launched its operation in Syria in August 2016 and almost came to blows with the SDF near Manbij in February and in March, the US sent units to Manbij to deter conflict. US-Turkey relations soured, but the regime played a role in brokering an agreement to create a buffer zone between the SDF and Turkish-backed rebels. It’s not entirely clear how this came about, but in early March 2017 the SDF ceded a strip of land to the regime. According to a report at Rudaw, “Under the agreement, villages west of the city [Manbij] will come under Syrian border guard control, putting a buffer between the Manbij Military Council and the Turkish and FSA forces engaged in Turkey’s operation Euphrates Shield in northern Syria.”

This means that the regime and SDF can work together. It also means the Russians and SDF can work together. However it appears that when it comes to regime and Russian suspicions of the US role, then they desire to show that they will carry out airstrikes “danger close” to warn off further advances. With only several thousand meters separating the forces now, the chances for a misunderstanding are greater. Russia has accused the US of breaking international law in strikes in Syria and after the US cruise missile strikes on the regime in April, there was a brief break in contact about Syria. However today is more sensitive because of the race for the Euphrates and the Iraqi border. It is also sensitive because of the agreements being hammered out on Idlib that include Turkey, Russia and Iran. After years of John Kerry’s failed diplomacy at Geneva, the Russians have taken the lead at Astana. In July the US, Russia and Jordan reached a deal about southern Syria. If you add it all up, Manbij, Afrin, Idlib, the south, and Deir ez-Zor, what you see is a series of different agreements, and in each the situation is different and in each the leading powers are different.

Where the US is strongest, near Raqqa, the Russians want to show the regime that they will strike where they want in Syrian territory, since in their view they were invited by the regime to aid the war against “terrorists.” The US is the interloper. De-confliction may work to avoid real conflict. But the red lines of the de-confliction lines will be tested, as they were on September 15th. What comes next in Deir Ez-Zor remains to be seen.