The US offers bonds in $ at a certain very low interest rate and China buys them in order to maintain their low yuan valuation. As stated in the article, this is to manipulate currency prices for domestic reasons to keep their exported goods "cheap" in terms of the global reserve currency, dollars.
Your cons are all messed up. They're making the dollar stronger and the yuan weaker, deliberately, and that makes our firms over-priced when exporting. We've had 1% inflation for like 5 years now.
If they didn't have that industrial policy, we'd probably have to be selling our 30-year tbonds at 3-4% instead of sub-1% as they are now. They do have the policy, so we should frankly be selling more bonds and spending the money on infrastructure, but hey, that's a hard story to sell for some reason.
