[TMWNN]

>Because they can force the rest of the world to keep using USD at gunpoint?

People and countries outside the US don't use the dollar because of the US military, any more than they use the Swiss franc because of the Swiss military. They use both currencies (and the UK pound, and the Euro, and the Japanese yen) because decades of experience show that the countries that issue said currencies are the least likely to default on their financial obligations, and are most transparent about their own financials.

Russians and Chinese themselves avoid using their own countries' currencies when abroad as much as possible because they are most aware of this. To put another way, the primacy of the dollar isn't a supply issue (something that the US directly forces), but a demand issue (it's the currency everyone else prefers to use).

(This is where you'll bring up the "petrodollar". No, the petrodollar isn't real. Well, it's real in the sense that oil is, like almost every other product, usually denominated in US dollars when sold internationally. What's not real is the theory that the US has a particular need for (say) Iraq back in the day to denominate its oil sales in dollars, as opposed to Euro. Or that Venezuela attempting to denominate its oil in yuan today surely augurs the collapse of the US economy tomorrow.)

[jkhdigital]

Countries started using the dollar because the US was the most powerful economy left standing after WW2 and thus the only trustworthy issuer of currency. The petrodollar system helped things along even after economies were rebuilt, as it meant that anyone who needed oil (i.e. everyone except OPEC) would also need to keep dollars on hand to pay for it.

After decades of this, we've reached the point where the US Dollar is so deeply embedded in nearly every global supply chain that everyone needs it all the time. I don't think it has anything to do with being transparent about financials or unlikely to default; it's just accepted everywhere and has a better stock-to-flow ratio (i.e. stability) than the alternatives.