Bitcoin has been around the borders of financial markets for less than a decade, but is slowly gaining importance as an alternative asset class.
Can the government of any major country step in and do the unlikely?
Yes the government of a country is free to do what they want. The government has the authority to do anything against Bitcoin, it could be bitcoin banned in a country and Bitcoin could be used legally because of a regulation that regulates Bitcoin. Some of the weaknesses that exist today are Bitcoin does not get the trust of a government. Governments are usually frightened because Bitcoin sometimes experiences negative price shocks, so this makes the basis for decisions to be made by a country's government.