I do not think that any country can pull Bitcoin down, anyone tried banned bitcoin in it country will regret it action because bitcoin generate employment to citizen of any country who allow bitcoin to function and add more to country economic development.
Not like a good number of countries never tried to ban Bitcoin, but fortunately for us, Bitcoin was well thought out by Satoshi and much more than what the governments bargained. Russia, China, India, all have made attempts to ban Bitcoin in the pass, but failed and now they have made a u turn.