I`m kind of surprised, no one mentioned the Petro-Dollar in this discussion?
So let me "mansplain"
Your money is just paper without any actual worth. 100 years ago, the US had the gold standard that backed up the dollar. For every dollar, you were able to trade it in for an ounce of gold. The dollar was like a contract or security and you did not have to carry gold with you around to pay for your stuff.
Before that system came into place, you had actual coins made of gold or silver etc.
So how is the dollar backed up now? Simply by trust which means by trust in the country itself, its trust in its economy as well as social and political stability etc.
But the US was able to instal another global backening system on the Dollar, the Petro-Dollar.
It means that every barrel of oil had to be traded in dollar on the international markets. So no matter where on the earth you were, if you had some dollars in your pocket, you were theoretically able to trade it in for some oil. Maybe you guys were not aware of this, but high tier economist and politicans for sure were.
Countries that abandoned the Petro-Dollar were put on political pressure or simply just bombed in the past. It happend to Hussein and to Gaddafi. Abandoning the Petro-Dollar was kind of the last straw this dictators took, as they were already weakened and politically cornered.
With the Ukranian war and the crisis with Russia, there was a global shift in the fiat system. Russia left the Petro-Dollar and is trading its oil in Rubel, which led to a big stabilisation and revalueation of its currency. The step is globaly acctpted by other big plays like china or the BRICS. Other countries are thinking of leaving the Petro-Dollar system as well or already left (I`m not sure about the latter one).
The problem for the US is, Russia can not simply be bombed into oblivion like Lybia or Irak.
Trump called the global abandoning of the Petro-Dollar one of the worst events that happened to the US economy and a desaster in foreing policy. However, no one talks about this or even is aware of this. Probably, because Trump is right on this one.