U.S. troops tasked with guarding oil wells in Syria from Islamic State group terrorists could also face threats from President Bashar al-Assad's regime, which has long sought to retake the Al Omar oil fields in Deir al-Zour province.
The announcement that U.S. troops would protect the oil fields came from Defense Secretary Mark Esper at a contentious Friday meeting with allies at NATO headquarters in Brussels. Several NATO members there denounced the invasion of Syria by NATO-ally Turkey.
"These are disagreements on a very serious situation in northeast Syria," NATO Secretary General Jens Stoltenberg said.
President Donald Trump ordered the withdrawal from Syria on Oct. 6. Three days later, the Turkish military attacked the Kurdish-led Syrian Democratic Forces (SDF) in northeastern Syria.
The U.S-partnered SDF has since struck cooperation deals with Syria and the Russians in seeking protection from Turkey. Both Syria and Russia have moved quickly to exploit the vacuum left by the U.S. partial withdrawal.
Syrian troops were in Raqqa and Tabqa, once the scenes of SDF victories over ISIS, Syria's state news agency SANA reported. Russian military police were taking over the former U.S. role in conducting joint patrols with Turkish forces in northeastern Syria, according to Russian news outlets.
SANA also reported that the Syrian army had clashed with Turkish forces in the northeastern city of Qamishli and Syrian troops were moving towards "the northwest countryside of the city to repel the Turkish offensive and protect people from any attacks."
In 2017 the SDF, backed by U.S. airpower and artillery, were in a race with the Syrian army, backed by Russian airstrikes, to drive ISIS out of the oilfields.
The SDF succeeded in taking the oil fields. But in February 2018 the SDF positions were menaced by an attack from what then-Defense Secretary Jim Mattis later described as "pro-regime forces" bolstered by Russian mercenaries.
U.S. Marine artillery fire and American airstrikes were ordered in response. Mattis later testified to the Senate Armed Services Committee that "the Russian high command in Syria assured us it was not their people" who were attacking.
With that, Mattis said he gave instructions to Marine Gen. Joseph Dunford, then chairman of the Joint Chiefs of Staff, "for the force, then, to be annihilated. And it was."
-- Richard Sisk can be reached at Richard.Sisk@Military.com.