Yield is determined by market demand, overwhelmingly by institutional (central banks) who were marginal buyers, i.e. when USD was geopolitically safe, countries

Yield is determined by market demand, overwhelmingly by institutional (central banks) who were marginal buyers, i.e. when USD was geopolitically safe, countries/central banks would buy without question for liquidity which artificially lowered rates. Now US fucked around with USD geopolitics, institutional buyers crowding to gold/commodities leaving private buyers (hedge funds etc) to fill demand hole, and private buyers demand higher yields because they buy for returns not liquidity. This why US debt servicing exploding - FED selling to more discerning market buyers and less to unquestioning institutional buyers. Where PRC comes in is they have large amount of USD reserves (and shadow USD from trade) used to parallel lend to governments (BRI etc) which replaces marginal FED USD demand with recycled PRC USD supply, which forces FEDS to find more market buyers, by increasing rates further to clear auctions. Every USD from PRC reserves that goes towards bilateral lending is one not bought from FED that has be be replaced by market buyer at higher yields. Net effect is PRC has functional influence over US treasury yield. Now fed has infinite power to move slider to compete on yield... but in practice that slider can only go the direction that makes US debt servicing more onerous. PRC leverage (JP limited geopolitically) = FED has little power to reverse debt trap but some power to go broke faster. Some power because at some point of $$$ brrrt printing buyers will realize US may not be able to honor commitments and price risk accordingly.