In practice, everyone wants to spend their dollars, not their gold, or their bitcoin, or their Euros, and so dollars it will be. What else is there that anyone both with pay with and will be accepted by the other party?
Again - you skip the full statement of the economic principle at hand.
No one cares that everyone wants to spend their dollars. They care whether the seller takes them, and is forced to take them at the same value as more cherished coin.
There is no functional mechanism to enforce this internationally - we already see the value of the dollar declining.
It's entrenched, so I expect the withdrawal to be relatively slow for the same reason you don't rip the bandaid off - you avoid a lot of pain. But there is nothing stopping the bandaid from coming off.
> you skip the full statement of the economic principle at hand.
Hence "In practice".
To the meat of your argument: sure, there's no mechanism to coerce it internationally, but it's self-perpetuating. Everybody could quit using dollars tomorrow. But they won't.
> we already see the value of the dollar declining.
This is not clearly the case. Its value relative to other currencies (as of this month), while subject to cyclical fluctuations, is on par for the post-Covid cycles and higher than pre-2020 levels [0].
Soon dollars might not be accepted if US companies wants to buy things in the EU, they will have to pay in euros (part of the anti coercion instrument that Macron and others have been talking about the last couple of days)
I don't think it will happen. 10% of EU bank loans that are dollar-denominated [0]. If they cut the flow of dollars into the EU, the debtors of those loans would wind up offering a premium for their goods and services to non-US companies, making them uncompetitive. It would be a roundabout tariff that would hurt the EU countries too much.
