As long as governments benefit more from modern slavery (which is what fiat money truly is), than from a form of money than is immune to outside control, they will not adopt BTC.
Russia or even places like Iran or Venezuela may have their problems with outside powers, but even for those countries fiat is still essential in extracting labor from their citizens.
On top of that Uncle Sam would probably "find" some weapons of mass destruction real quick if a country adopts BTC as a currency. Heck, look at Iraq, when they tried to adopt another fiat than USD (EUR).
