Old joke: If you owe the bank a thousand dollars and you can't pay it back, then you have a problem. If you owe the bank a billion dollars and you can't pay it back, then the bank has a problem.
It'd have to get very bad for China to pull out. If China pulls out and damages our economy, our imports will dry up, their exports will dry up and their economy will dry up. I understand that China and the US might not be the best of friends right now, but their interests are generally aligned on US debt.
Its really not. If what you say was true they wouldn't still be actively buying U.S. Debt.
Their hesitation is they wouldn't get all their money back. If China pulled even 25% of its investments out of the U.S. the dollar would free fall. They wouldn't be able to cash out before most of the dollars value was inflated away.
China continues to buy our debt because they don't want the value of their current investment to collapse
