The regions currently administered by the Kurds in Syria include the Kurdish-majority Qamishli and al-Hasakah in northeastern Syria, and the Arab-majority towns of Manbij to the west of the Euphrates River in northern Syria and Kobani to the east of the Euphrates River along the Turkish border.
The oil- and natural gas-rich Deir al-Zor governorate in eastern Syria has been contested between the Syrian government and the Kurdish-led Syrian Democratic Forces, and it also contains a few pockets of the remnants of the Islamic State militants alongside both eastern and western banks of the Euphrates River.
The Turkish “east of Euphrates” military doctrine basically means that the Turkish armed forces would not tolerate the presence of the Syrian PYD/YPG Kurds – which the Turks regard as “terrorists” allied to the PKK Kurdish separatist group in Turkey – in Manbij and Kobani, in line with the longstanding Turkish policy of denying the Kurds any Syrian territory to the west of the Euphrates River in northern Syria along Turkey’s southern border.
On Friday, the Syrian army said it entered Manbij for the first time in years, after the Syrian Kurds urged Damascus to protect the town from the threat of impending Turkish military offensive, though Turkish President Erdogan has termed the handover a “psyops” by the Kurds.
According to a report by RT
:  “A high-ranking Turkish delegation arrived in Moscow on Saturday, only a day after international media broke news on Kurdish militias inviting Syrian forces to enter Manbij before the Turks do. Syria’s military proclaimed they ‘raised the flag’ over Manbij, but there have been no independent reports confirming the moving of troops into the city.”
The report notes: “The Saturday Moscow meeting was key to preventing all actors of the Syrian war from locking horns over the Kurdish enclave, Middle East experts believe.”
“Obviously, Turkey will insist that it is their forces that should enter Manbij, Russia will of course insist the city should be handed over to Assad’s forces,” Kirill Semenov, an Islamic studies expert with Russia’s Institute for Innovative Development, told RT.
The report further adds: “Realpolitik, of course, plays a role here as various locations across Syria might be used as a bargaining chip by all parties to the conflict. Semenov suggested the Turks may agree on Syrian forces taking some parts of Idlib province in exchange for Damascus’ consent for a Turkish offensive toward Manbij or Kobani.”
It becomes abundantly clear after reading the RT report that a land swap agreement between Ankara and Damascus under the auspices of Moscow is in the offing to avoid standoff over Manbij.
The agreement would likely stipulate that Damascus would give Ankara free hand to mount offensives in the Kurdish-occupied Manbij and Kobani in northern Syria in return for Ankara withdrawing its militant proxies from Maarat al-Numan, Khan Sheikhoun and Jisr al-Shughour, all of which are strategically located in the south of Idlib governorate.
Just as Ankara cannot tolerate the presence of the Kurds in northern Syria along Turkey’s southern border in line with its “east of Euphrates” military doctrine, similarly even Ankara would acknowledge the fact that Damascus cannot possibly conceive the long-term presence of Ankara’s jihadist proxies in the aforementioned strategic locations in the south of Idlib governorate threatening the Alawite heartland of coastal Latakia.
If such a land swap agreement is concluded between Ankara and Damascus, it would be a win-win for all parties to the Syrian conflict, excluding the Kurds, of course. But the response of Damascus and Moscow to the concerns of the Kurds has been tepid of late.
Not only have the Kurds committed the perfidy of acting as the proxies of Washington during the Syrian conflict which abandoned them after Trump’s announcement of withdrawal of American troops from Syria, but we must also recall another momentous event that took place in Deir al-Zor governorate in February.
On February 7, the US B-52 bombers and Apache helicopters struck a contingent of Syrian government troops and allied forces in Deir al-Zor that reportedly
 killed and wounded scores of Russian military contractors working for the Russian private security firm, the Wagner group.
The survivors described the bombing as an absolute massacre, and Kremlin lost more Russian citizens in one day than it had lost throughout its more than three-year-long military campaign in support of the Syrian government since September 2015.
The reason why Washington struck Russian contractors working in Syria was that the US-backed and Kurdish-led Syrian Democratic Forces (SDF) – which is mainly comprised of Kurdish YPG militias – had reportedly handed over the control of some areas east of Euphrates River to Deir al-Zor Military Council (DMC), which is the Arab-led component of SDF, and had relocated several battalions of Kurdish YPG militias to Afrin and along Syria’s northern border with Turkey in order to defend the Kurdish-held areas against the onslaught of the Turkish armed forces and allied Syrian militant proxies during Ankara’s “Operation Olive Branch” in Syria’s northwest that lasted from January to March 2017.
Syrian forces with the backing of Russian contractors took advantage of the opportunity and crossed the Euphrates River to capture an oil refinery located to the east of Euphrates River in the Kurdish-held area of Deir al-Zor.
The US Air Force responded with full force, knowing well the ragtag Arab component of SDF – mainly comprised of local Arab tribesmen and mercenaries to make the Kurdish-led SDF appear more representative and inclusive – was simply not a match for the superior training and arms of Syrian troops and Russian military contractors, consequently causing a carnage in which scores of Russian citizens lost their lives. Clearly, Moscow and Damascus hold the Kurds responsible for the atrocity along with Washington.
Regarding the dominant group of Syrian militants in the Idlib governorate, according to a May 2017 report
 by CBC Canada, Hayat Tahrir al-Sham (HTS), which was formerly known as al-Nusra Front until July 2016 and then as Jabhat Fateh al-Sham (JFS) until January 2017, had been removed from the terror watch-list of the US after it merged with fighters from Zenki Brigade and hardline jihadists from Ahrar al-Sham and rebranded itself as Hayat Tahrir al-Sham (HTS) in January 2017.
The US State Department is hesitant to label Hayat Tahrir al-Sham (HTS) a terror group, despite the group’s links to al-Qaeda, as the US government had directly funded and armed the Zenki Brigade, one of the constituents of Hayat Tahrir al-Sham (HTS), with sophisticated weaponry including the US-made antitank missiles.
The purpose behind the rebranding of al-Nusra Front, first as Jabhat Fateh al-Sham (JFS) and then as Hayat Tahrir al-Sham (HTS) and purported severing of ties with al-Qaeda, was to legitimize itself and to make it easier for its patrons to send money and arms.
Washington blacklisted al-Nusra Front in December 2012 and persuaded its regional allies Saudi Arabia and Turkey to ban it, too. Although al-Nusra Front’s name has been in the list of proscribed organizations of Saudi Arabia and Turkey since 2014, it kept receiving money and arms from its regional patrons.
Finally, regarding the deep ideological ties between the Islamic State and al-Nusra Front, although the current al-Nusra Front has been led by Abu Mohammad al-Jolani, he was appointed
 as the emir of al-Nusra Front by Abu Bakr al Baghdadi, the leader of the Islamic State, in January 2012. In fact, al-Jolani’s Nusra Front is only a splinter group of the Islamic State, which split from its parent organization in April 2013 over a leadership dispute between the two organizations.
Sources and links:
 Land swap between Turkey and Syria – an option to avoid standoff over Manbij:
 Russian toll in Syria battle was 300 killed and wounded:
 Syria’s al-Qaeda affiliate escapes from terror list:
 Al-Julani was appointed as the emir of al-Nusra Front by al-Baghdadi: