Well historically Taiwan could argue China is the renegade province. See other comments in this thread for the context.

I think you are missing the main point. Despite an arbitration court ruling against it, China decided all of the China Sea is theirs: https://im-media.voltron.voanews.com/Drupal/01live-166/style...

"The South China Sea Arbitration (The Republic of Philippines v. The People's Republic of China)" https://pca-cpa.org/en/cases/7/

Started making artificial islands in the middle of nowhere, and now says all foreign vessels need to report in their ‘territorial waters’.

"China to require foreign vessels to report in ‘territorial waters’" https://news.ycombinator.com/item?id=28395358

Have a look at a map, and see the distance from Yonaguni ( Japan ) to Taiwan and the distance Yonaguni to mainland Japan. You think China will do what they are doing in Hong Kong, Xinjiang, South China Sea and suddenly...Come to their senses and stop, specially if unchallenged for previous actions?

If they do this in the other side of the world: "Hundreds of fishing vessels vanishing along Argentina’s waters" https://news.ycombinator.com/item?id=27412691

What will they do at their door?