Chinese buying of American debt is what is keeping the dollar artificially strong compared to the Chinese currency.
The minute China stops buying American debt , their currency exchange rate will double, killing their export business to the US.
This could be a bit problematic because the entire Chinese economy is dependent upon exports to the US to keep their economy, which is a mile wide but an inch deep, going at it’s current. pace.
Any exchange rate spike against the dollar will implode the Chinese economy and the only thing preventing such a spike is massive Chinese purchase of American debt.
They do know this, and are increasing their purchase of assets here, especially real estate.