No part of the financial system is exposed by Bitcoin, and its behaviour means it never will be. Its impossible to price in it for more than a few minutes, so it just cant be used contractually in normal business. To hedge it, you would have to revert to normal currency, which sort of defeats the purpose, no?
Look at countries whose currencies got out of control like Argentina for a while or Venezuela. Everything ended up priced in dollars, because otherwise external business is impossible.
And no country is going to accept it has pay some random people a fortune for use of a currency it didnt create. I see the Bank of England is looking into creating its own blockchain currency. And it wont require huge amounts of computer power, it will just be created and registered.