Syria and Russia are not the real concern in the region. The real questions are what does Iran and Hezbollah expect in return for their help and what will that do to the region? Also what becomes of the remaining Sunni's in Iraq and Syria? What will be the next stage in the Global Sunni-Shite Civil War?
Hopefully it will get bigger and bloodier, and yes, I understand that it will spill over into Europe, North America and Australia, etc, too, but a few outrages here and there is a small price to pay for an all out, tooth and claw, Islamic version of the 30 Years War ... but maybe a little more ugly.