They will have to send troops first advisers, then special forces, then their conscripts. They have tied their fate to Assad and they will get pulled in. So they will get their own Iraq, the war will prove to be unpopular with the people as Chechnya and Afghanistan was due to conscripts being used.. There is already unrest in Russia. So you have Russian propping up another dictator, another Afghanistan, and a Carter in the WH. You have Iran threaten the Straits of Hormuz which they did in the past, the world has regressed., it is the 80's.
Palestinian Red Crescent: 568 Palestinians wounded in W. Bank and E. Jerusalem on Saturday (Haaretz)
from the article: Only Putin can decide if - and when - Assad will step down