Russia is like France in France hitting that ISIS camp, both countries have to worry about ISIS planning attacks on the home-country.
Plenty of Russian and other citizens of the former USSR are in the ISIS army.
Radio Free Europe devotes a whole section to it: http://www.rferl.org/archive/under-the-black-flag/latest/17257/17257.html
Putin has already agreed for Assad to share power, as if this is the great success story some tout it to be.