Many people American and worldwide used to buy our Obama_gov’t issued Federal debt. The Chinese stopped about two years ago.
So the Federal Reserve (a private bank owned by our largest American banks) stepped into the breach and is buying what the Chinese and others used to
(simplified explanation)
More frightening than the Chinese owning just less than 10% of our debt is that the government pension system owns over 1/3rd. That is money that will have to be paid.... round and round we go.....