It would be a huge step forward for crypto currencies if a country would decide to pay everything in bitcoins going forward. As this is never done before it would be a case study for the future and if successful many countries would follow. The best would be if a small country would try to do it first, the less people living there the less transactions will be needed. Also it should always be an option, every citizen should be able to choose between paying and receiving money in bitcoin or his local currencies. Forcing a whole country to adopt bitcoin without alternative could lead to a big backlash. Then it would make sense for a country to accept all tax payments or other income from the government to be paid in bitcoin. Because if they start paying out large sums of money in bitcoins, they need to get the coins somewhere. And if they have to buy the coins every month via an exchange it makes them predictable and some trader could try and take advantage of them. The best case would be if the government could match their income and expenses, avoiding to run a deficit and making their currency more stable for the link to bitcoins. But it shouldn't be that the government will exchange large amounts of their currency for bitcoins for private investors, or the other way round.