“There’s no way the US can find buyers of $9 trillion in bonds for one year.”
There is an old joke that solves this mystery.
A man walks up to a strange woman and says:
“Will you have sex with me for a billion dollars?
She says: “For a billion dollars. You really have a billion dollars to give me. Well, OK. Let’s go back to my place.”
He says: “Now we have established what you are. All that remains to be discussed is the price.”
There are always buyers for anything—at the right price.