From China insisting that the two lands will be united no matter what while building weapons aimed at Taiwan and systems that will be very effective at shooting at Taiwan and building literal invasion barges that are only usable at invading little islands that have heavily built up the defenses on their beaches.

Gee, I wonder where it comes from

There’s no way China is going to be an aggressor. It’s more akin to “don’t come into my lawn or else”. If you don’t go into their lawn nothing happens.

Well their rhetoric says otherwise.

Probably from China's claims that Taiwan is part of China.