European countries' leaders are America's cocksuckers in case you haven't noticed. And believe me, they swallow.
They will do anything Obama asks them, and waggle their tail, happy they could serve their master.
So yes it will be countries that are on not so good terms with the US that could allow BTC to continue to operate - and the US leaders know this. This is what worries them; if they decide to force their citizens to stay out of BTC, they could miss the train and, at some point, that train could become so large that it competes with USD. Imagine a world currency called BTC; used by China, Russia, South America etc, to sell goods like oil for BTC? OMG!! BTC a competitor for the Dark Empire's IMF drawing rights? 21 million BTC can represent 2100 trillion US cents, so the sky is the limit.
That is why BTC has not been attacked full force, methinks.