Russia has dropped a significant amount of personnel and hardware in Syria. They’ve established an SLOC and an ALOC. I don’t think they’re there for limited contingency operations.
They may get chewed up like they did in Afghanistan, but no matter who loses, we win, as they grind each other down.
Putin has put 200 ground troops, 6 T-90 tanks and support crews and pilots for the couple dozen military aircraft and helicopters.
That’s not nearly enough to stop ISIS let alone turn them back.
The big problem will come when those troops with their lousy discipline start wandering away from their bases out of boredom and get nabbed by ISiS.