The funny part is that this if done 2 decades ago would have spent doom for China but would have also run yahoo for the USA as well. But now if they really did this, not only will China be able to whether the storm with more countries willing to fill the gap (South America and Africa and even other nations in Europe) but this will spell doom for the USA for real as there system can only function due to being able to print money. If that was to be taken away and if they lose the chance for future investment (since how are they going to find employment for 50million unemployed) well the USA can’t be saved and it will not be in the best interest for other countries to bother saving them since that will help to open new pathways for there nations instead if they let the USA go down
The power of the US dollar as a medium of exchange comes from the Petrodollar i.e. the fact that oil is priced in USD. That is vigorously enforced by the US Navy basically controlling access to the Persian Gulf and occupying strategic nations in the Persian Gulf.
That is also part of the reason why the US is so insistent on putting one of their own puppets in Venezuela another nation with large oil reserves.
So the guarantee of the value of the USD is US military power. To break this you would need to either replace the US on that part of the equation or you would need to come out with some other more fungible energy source and use that for global energy trade.
Some people have proposed using hydrogen for this but that is unviable for several reasons. Others have proposed ammonia, which is more viable, but ammonia is highly toxic, corrosive, explosive, and expensive to manufacture. I personally think the best alternative is to switch to electric transportation as much as possible. Then you can use multiple energy generation sources and the energy market will be a lot more diverse as a result making it less easy to corner the world economy like this. One issue is this would require a much more advanced energy transmission infrastructure but we are on the cusp of having this technology ever since ballistic conductors were invented (basically you can use carbon nanotube wires to transmit electricity at high voltage and they will have a lot more capacity than copper even can). Even without that with a decent public transportation network and reduced personal car usage even the existing electric grid would be good enough.
The US would still likely try to enforce their power by controlling the sea lanes much like other earlier sea empires did. The only way to prevent this is to have your own navy which is what China is doing right now.