By "country" you mean government right? Well, let's say for this argument you are referring to the government of a country accepting Bitcoin as a reserve currency. I can tell you now that it will not happen, because most of these governments rely strongly on the ability to manipulate the value of their own reserve currencies and they will not allow a global "open" market to determine the value of their own reserve currency.
Yes, some countries embraced Bitcoin as a "payment option" like PayPal, but it does not replace their own reserve currency. A country like Japan already saw the advantages of being Bitcoin friendly and they will prosper in a global context.