Here's the problem for China with "bringing down the West." The countries comprising the West are the ones most of China's consumer goods are exported to. Hurting those country's ability to purchase Chinese goods hurts China.
That fact may be about the only saving grace with respect to its ownership of so much of our debt. It could do significant harm to the US should it stop buying and or start selling the debt they hold. It would cause US bond yields to rise, making the issuance of future debt more expensive for us by having to pay a higher interest rate.
But if China breaks us, it essentially breaks itself. Therefore, the Right's hated global economy may be the only thing saving the US from China pulling the proverbial rug out from under us.