I could see China preferring a neutral hard money to the US dollar as the global reserve currency whereby the US can export all its inflation and basically has an infinite money glitch.
Similarly I could see the US supporting a neutral hard money, if the dollar was about to lose its current position. The US would probably rather see Bitcoin as global currency, than a fiat currency if its rivals in the BRICS.

Basically if you asked every country on earth to rank which currency they would like to see as global standard,it would probably always be Bitcoin/gold on second place right after their own fiat currency.