Russia can just get Iran to provide the support.
Iran has been all-in for four years in Syria, it's gotten worse, and couldn't even pull off Ramadi a second time with all the Iraqi armed forces and Shiite jihadist militias it could herd into the kill zone. Just a couple weeks back the meme was that ISIS was in retreat and Iran and its proxies were kicking its ass. Then Assad's Aleppo offensive failed, Ramadi fell, Palmyra fell, and a dozen or so jihadist militias were beating Assad and Iranian proxies all over Syria. The towel-head in charge of the Hizzies has been ranting that everyone must try harder, even if it means HALF of them wind up martyrs.
A week ago the buzz was that the US and Iran would cooperate in the retaking of Ramadi, this week Zero and Co. stated that Iraq was not our problem. While hunting around I noticed that the Iraqi "government" (puppet of Iran) estimated that 2200 Humvees were lost when ISIS took Mosul. 2200! While attention is in Iraq and Syria, the US' move should be loading up the Kurds with everything they need -- but there's a Turkish election coming up and Erdogan appears to be losing. Anything we do to help the Kurds would give him a ramrod issue. Of course, this wouldn't be a problem if we'd just have his ass killed, but maybe that's a bit rash.
Saw this thread last night, Russia has already distanced themselves from Assad in the past 18 months.
Syria was a good Soviet-aligned state in the old days with Hafez Assad.