China divesting themselves of U.S. Treasuries...prelude to war? [View all]

In just one year, China has lowered their U.S. treasury holdings by $200 Billion. We know China is looking to invade Taiwan at some point in the future which would bring it into direct confrontation with the U.S. At what level of treasury holdings do they decide they can write off the remaining amount in exchange for their invasion?

https://ticdata.treasury.gov/Publish/mfh.txt