The US had 100 years of trade surpluses (until 1970) exporting overcapacity in manufacturing with high tariffs, then 70 years of reverse history (deficit), so asking US to 'pay back' through current deficits is question of whether rebalancing now is unfair after US benefited for century.

Being the dominant currency comes with privilege (financing deficits at lower rates) but also comes with cost (Fed must backstop global system); the question is whether US dominance is 'fair' or just 'price to pay for privilege.'