well, yes, the Wahhabis/Islamists hate moderate Muslims the most. But, Islamist are just the loud minority in all Muslim states. Even in Afghanistan!
But, somehow, they are able to spread out and take control.
Russians are not afraid of their Muslims, but they are afraid of foreign agitators. They can make a lot of trouble.
Yeah you right foreign agitator may do a trouble. But our Muslims know that islamists are their enemy in first place and they are not blind and see how things are going in the islamic states. They don’t want it for themselves.
And last they know that FSB will be all over you if you give them any help. So Russia is cautious but not afraid.