the game is this: USA buys "stuff" around the world and gives a piece of paper in return since basically everybody uses the same piece of paper, then it has a meaningful value. once at least 40% of world payments is outside USdollars then the whole game starts to wobble once it reaches 60% it will just fail, USA will not be able to buy "stuff" with a nice printed piece of paper this is the reason to destroy russia and china