It's supported and influenced by the USA in the sense that if you can't ever turn it into dollars it becomes much less interesting.
replyAnything anyone wants to spend money on, can be converted into dollars. The currency has no tell in what it is used for.
replyThe hypothetical was that the US "bans" bitcoin, presumably meaning it becomes illegal for US financial institutions (or US-dependent ones, which is nearly all of them) to convert bitcoin to dollars. Somebody else might give you dollars for bitcoin, but then it becomes their problem. As the saying goes, "you can't eat bitcoin".
replyIt's not like the Dollar is the only worthwhile currency.
replyConvert it into Euros. Or Yen. Or Yuan.
You could make it prohibitively problematic to use for most things.
replyYou do what the the US is doing right now to starve Cuba & end civilization there: you embargo/sanction anyone doing business there.
replyLike the Treasury/Dept of Commerce & others did with North Korean backed Tornado Cash. Some very quickly retrieved/not well researched (caveat reader) search links; https://home.treasury.gov/news/press-releases/jy0916 https://www.paulhastings.com/insights/crypto-policy-tracker/...