De: Re: “...his historical research has shown him that money has to have a direct link to a government to endure.”
I'm not impressed with his historical research. The most enduring form of money, by far, is gold. Gold does not have a direct link to any government.
I don't want to put words into Pozar's mouth, but his definition of "money" and your definition of "money" might be fairly different.
The defnitions I've seen for "money" include, ideally both, (1) a medium of exchange and (2) a store of value. #1 and #2 don't, naturally, go together very well.
Certainly the current fiat currencies do NOT store value very well and are, indeed, guaranteed to eventually become worthless -- likely in a twinkling as we near the end.
On the other side of that coin;-}, gold doesn't form a very good medium of exchange in anything resembling the current world because it is not a good medium of exchange. The REASON it is not a good medium of exchange is because of Says Law: "Bad money drives out good". That means, that when bad money competes with good money, the good money is hoarded and the bad money is circulated.
Bitcoin has a massive number of flaws, including it is really easy to liberate all of someones' bitcoin and, once it is gone, you and all the honest police in the world likely won't be able to track it down and return it to you. It is remarkably easy to steal. So easy to steal, in fact, that you'd be wise to carry a concealed gun if you ever carry a wallet of bitcoin.
Anyway, that is where the government comes in -- or could come in. And I think that might be at least part of what Pozar is trying to communicate.