The dirty little secret is that we don’t owe the national debt to china et-al, but to the FED.
Since the debt is fiat dollars, it was created out of thin air by the FED, and the interest on it goes towards paying the owners of the FED and about 300 FED stockholders. THe FED, non-federal, is just a private banking corporation that we (the US) tasked with printing the currency, and we pay them interest on that which they create.
Having paid a plug nickel in principal.
“debt” held by China/et-al is merely them holding the “debt” created by the FED in the first place.