Your question is the answer: Putin would rather fight - and slaughter - jihadists in Syria than in the Southern Caucusus. He won't be sending troops there to nation build, but to break things and kill people.
Putin is corrupt as heck, but he does understand the real world about 1,000,000,000 times better than obastard...
Hmmm. This would be an irony of Biblical proportions.
Formerly Christian America becomes Israel's defacto enemy.
Formerly Atheist Russia becomes Israel's defacto savior.