The Russian Orthodox Church isn’t known as “Christianity’s dark side” for nothing. Catholic and Evangelical missionaries in Russia are treated worse than muzzies.
It’s very far from obvious to me at least that Russia needs missionaries of any sort. They are building two hundred new Christian churches in and around Moscow and they have totally rebuilt the magnificent Cathedral of Christ the Savior. Between Russia and the U.S. right now it seems obvious enough as to which is the Christian nation, and it ain’t us.