>My government will enforce a contract even if it is denominated in some foreign currency, will it not?
Sure, if usage of that other currency is trivial enough volume that it doesn't threaten the government's currency. That's the sticking point. Bitcoin is allowed to exist at the whim of the government.
Since deflationary Bitcoin in no way, shape, or form threatens central bank currency systems, I don’t think existing at the sufferance of central governments is anywhere on the roadmap of problems crypto currencies have.
Sure, if usage of that other currency is trivial enough volume that it doesn't threaten the government's currency. That's the sticking point. Bitcoin is allowed to exist at the whim of the government.