If bitcoin is proved to be useful and successful in other countries. The government which ban the bitcoin will legalize it and its people will benefit from it.
It will be quite opposite, if bitcoin will be successful, governments will see BTC as a threat to their own controlled currency.
And will try to ban, regulate or convince people that bitcoin is not trustworthy to invest in.
Well it can be the opposite or not, im not saying that they will try to win in some way with it, ofc that they will try to do that, thats his "style of life", but what will happen if bitcoin is big enough to don't let them do it and people choose to work with bitcoin instead of his own currency money?
Obviously this is a perfect scenario, but don't forget that is a possible scenario and the more that they wait to adopt it, bitcoin become more stronger.