Defense Secretary James Mattis revealed Tuesday that U.S. forces nearly bombed Russians fighting on behalf of Syrian President Bashar al-Assad sometime in the past week, but a call with Moscow's own armed forces defused the situation.
Mattis said he believed Russian military officials when they said they were not giving orders to private Russian citizens battling the Islamic State militant group (ISIS) and rebel groups as part of a coalition of pro-Syrian government militias. Following an incident last month, in which the U.S.-led coalition against ISIS killed a large number of these pro-Assad fighters, including Russians, Mattis said another clash was recently avoided after Marine Corps General Joseph Dunford, chairman of the Joint Chiefs of Staff, contacted Russia's top military leader, Army General Valery Gerasimov, via a deconfliction hotline.
Not long after, the mostly Arab faction of the Syrian Democratic Forces in eastern Syria said they had come under attack by pro-Syrian government forces. The U.S.-led coalition responded with massive force, killing up to 100 pro-Assad fighters, including at least dozens of Russian citizens—many of which were reportedly operating as part of private military companies.
"There were other Russian elements like this moving across the deconfliction line, which is the river, as you know, into an area that we'd agreed with the Russians they could operate in, as they had allowed us to operate basically to the west of the river, up at Tabqa and around Raqqa. We'd agreed for them being slightly east of the river at Deir Ezzor," Mattis told reporters at the Pentagon.
"These were forces moving into more advanced positions, too close.
Deconfliction discussions between our chairman and his Russian counterpart, General Gerasimov [took place] and those elements fell back. So we have also drawn off slightly in order to maintain a deconfliction between the elements there," he continued.
"So it looks like, this time, it was resolved through the deconfliction communication line. It did not, you know, go into harm's way, as it did there a month ago," he added.