The US military presence in Syria is facing increased opposition, as its initial justification for being there — destroying the Islamic State (ISIS) — is gradually evaporating.
US officials say they are retaining troops in Syria's northeastern Kurdish regions (Rojava) for post-ISIS stabilization efforts, or even until the conflict in all of Syria is brought to an end through negotiations. Either of these things could well mean that the US will remain in Rojava for the long run, and with approximately 2,000 troops [only the 400 US Marines manning artillery on the front-lines during the Raqqa offensive have returned home to date] and a series of bases remaining, it has a highly formidable military presence in Syria.
The United States is allied with the Syrian Kurdish People's Protection Units (YPG) forces and the Syrian Democratic Forces (SDF) Arab-Kurdish fighting-force, of which the YPG is an integral part. These forces control the vast majority of Syria's northeast, its de-facto frontier with the rest of the country roughly conforming alongside the east bank of Euphrates River. These areas are also where Syria's oil reserves are situated, all of which were recently seized by the SDF from ISIS.
Damascus has come into more open conflict with the Kurds in recent months. In December Syrian President Bashar al-Assad called them "traitors" for working with the Americans. In January the US also faced firm opposition over its plans to build a 30,000-strong SDF border-guard force from the Syrian regime, Iran, Russia and Turkey – all of which alleged that this was part of some broader US plot to partition Syria. Washington would later claim that the whole thing was a misunderstanding.
On February 7 an attempt by approximately 500 paramilitaries – both pro-regime Iranian-trained militias and Russian mercenaries – backed up by tanks and artillery to attack an SDF headquarters in Deir ez-Zor province was promptly foiled by an array of US military aircraft (reportedly including everything from Apache attack helicopters to F-15E strike aircraft and AC-130 gunships) which heavily bombarded these forces, killing an unspecified number of them. A single T-72 tank was also destroyed by US air power on February 13 after reportedly firing on SDF positions.
The United States previously shot down a Syrian Su-22 warplane near Tabqa last summer when it attempted to attack the SDF, the first time a US fighter jet shot down another aircraft in an air-to-air engagement since the Kosovo War in 1999.
These incidents — coupled with US downing of Iranian drones and bombing of regime ground forces approaching at-Tanf, where the US coalition has a training base for anti-ISIS forces near the Jordanian border last year — all demonstrate Washington's capability to swiftly and forcefully defend its positions across Syria.
It's not yet clear if these latest developments were indicative of a regime effort to wrest control over some of the peripheral territories controlled by the SDF in Deir ez-Zor or a more general effort to challenge the US military presence in northeast Syria.
Nevertheless both Damascus and Moscow slammed the US presence in Rojava as "illegal" following the February 7 incident. When US Secretary of State Rex Tillerson called on Iran to withdraw its forces from Syria on February 14, Tehran reiterated its condemnation of the American presence and, once again, pointed out that unlike Washington, its military presence, mostly consisting of advisors training proxy militias, in the country is authorized by Damascus.
Russian Foreign Ministry Spokeswoman Maria Zakharova also lambasted the United States on February 15 by alleging that its presence in Al-Tanf is aimed at protecting remnants of ISIS. She also described the February 7 airstrikes as "defiant actions" which brought Washington "close to an open confrontation with the Syrian army."
As its presence in Syria is facing greater opposition from the regime and its Russian and Iranian backers, Washington will have to decide how far it's willing to go to defend its foothold in Rojava and its SDF/YPG allies. The US already clearly has de-facto no-fly and no-drive zones across Rojava, with the salient exception of Afrin Canton, to deter Damascus from attempting to re-subjugate the region. However as the ISIS threat recedes, and the Assad regime becomes more emboldened having reconquered most of the country, Washington's main objective in Syria may well shift gradually from solely destroying ISIS to combating Damascus itself.
