An American general speaking of the final fight against ISIL in Syria noted that we and the Russians have "lines" to keep our forces apart:
So we're having a conversation with the Russians. We're trying to de-conflict this in the future. And we have lines that are agreed to that will cover much of the Middle Euphrates River Valley now; not all of it yet, but we'll get to that when the time comes.
I probably shouldn't read too much into a briefing answer. But could this be the birth of a Russian-backed West Syria and an American- and Arab-backed East Syria (which might run along the northern Jordanian border to reach the Israeli border)?
Deconfliction lines could easily become a new border of new political entities.
Assad's forces, probably enabled by ceasefires in the west that free up the pro-regime mobile forces, are pushing east into the vacuum created by our growing defeat of ISIL, to stake out as much territory as possible:
Syria's army and its allies raced towards their enclave in Deir al-Zor after a rapid advance on Sunday, seeking to relieve it after years of Islamic State siege as jihadist defenses suddenly collapsed.
If this kind of informal division takes place, it would leave rebels in the northwest an odd man out, unless Turkey backs them to maintain a buffer zone.
UPDATE: Pro-Assad Syrian forces have punched through to the city although not the airfield.
I never understood why ISIL didn't make a greater effort to take that enclave. Losing another enclave and the people holding or sheltered in it could have had a dramatic effect on Assad's supporters.
UPDATE: If you've been paying attention, our deep involvement in Syria is not news. The major change in 2017 is that we are being more effective in that involvement.
UPDATE: The Euphrates River could be a major portion of a new DMZ, rather than stretching to the Syria-Jordan border and screening Iraq fully:
U.S.-backed militias and the Syrian army advanced in separate offensives against Islamic State in eastern Syria on Saturday, piling pressure on shrinking territory the group still holds in oil-rich areas near the Iraqi border.
The Syrian Democratic Forces (SDF), a U.S.-backed alliance of mostly Arab and Kurdish fighters, launched a new operation against the jihadists in the north of Deir al-Zor province that aims to capture areas north and east of the Euphrates river.
Syrian government forces and their allies, backed by Russia and Iran, meanwhile seized an oilfield from militants on the other side of the Euphrates and recaptured part of a road linking Deir al-Zor to areas held by IS further downstream.
We'll see. Assad's drive east is the reason I wanted to delay an offensive against ISIL in Syria until after we built up rebel forces in Syria to fill the vacuum left by the defeat of ISIL.
But I also thought we'd get the Iraqi military moving much more quickly than we did. Which is probably from my failure to appreciate the difficulty of the job more than an excess of caution in moving against what was really a small ISIL force controlling northwestern Iraq. But I don't know for sure, of course.
UPDATE: Also, we lifted our UAV surveillance of an ISIL convoy coming from Lebanon stuck in the desert to deconflict with Russian planes in the battle at Deir al-Zor.
Which seems to imply a division of territory flowing from the division of air space.
UPDATE: More on "the race" to replace ISIL out there.
UPDATE: On Sunday, news that American-backed forces are about 10 miles from the pro-Assad elements around the city.
