The Russians are between a rock and a hard place.
They were originally very good at repelling Islamists, but then, probably mostly because of Western pressure but also because of terrorist attacks on Moscow, they decided to make an alliance with certain groups (just as we did, which is why we are having such problems in the ME).
Islam is poison to any society it takes over and poison to any society that allies with it in any way.
You CANNOT make an “Alliance” with a rattlesnake