You are utterly naive and ill-informed if you believe that Russia is not a major strategic threat to the West.
Nato thinks Russia is on par with Daesh
NATO Chief Names IS and Russia as Greatest Threats to Peace | News | The Moscow Times
Russia, views NATO as enemy number 1
https://www.rt.com/news/217823-putin...tary-doctrine/
Russia is not in Syria to fight 'terrorism' they are their to defend their strategic interests, Assad at this point but their naval base in reality. Syria is extremely important to them, its geographically close. But they are not there to fight Daesh and Russia is not our ally. Russia will will their situation to attack and weaken Nato.
Repeatedly overflying Turkey and bombing the border crossing were a deliberate policy to attack and weaken Nato. Divide and conquer via Hybrid Warfare is their goal.
The Russians believe the Holy Russia Empire is the descendant of the Roman Empire they are the want to rebuild their empire. Nato has been cast as The Nazi's and they see them selves as the rebuilt Soviet Empire with a heavy dose of Religious fanaticism added.
I think a nuclear armed nation who believes it has a divine right to rebuild its Empire, through the destruction of Godless, debauched savages (you) is more of a threat than IS.