Come the fuck on. Taiwan was returned to China after WW2. It's where the Chinese national govt fled to (you know, adversary), it's populated by Chinese, and is strategically important because it blocks China in. I don't like the situation any more than anyone else but let's discuss it intelligently rather than stupid gotchas.
What do you think the situation would be if the US Civil War ended in a stalemate? Either side drove the other to Long Island, except in this case Long Island controls all your sea access. (If they were both adamant on taking over the other and neither side signed a peace treaty.) That's what this is, it's a civil war that never ended. I'm going to leave the rest of that one alone, but you should explore your line of thinking on it.
Here's a thought experiment: Take the US civil war, the Confederacy says it's the real US. Does that make it a country? Does the North get to say anything about that? Who decides what?
In this case Taiwan has never said it's it's own country, you can thank the delusional kmt for that. They (Taiwan) said they are the real China. So in our thought experiment: the Confederacy says it's the US, the North says it's the US, and nothing goes anywhere. Who gets to say what? Do foreign countries get a say?
This is not half the country splitting up, this is an island.
If the confederacy evacuated to florida, diverged culturally, was defacto independent and minding thier own business other than some stupid ancient political fued that doesn't matter?
Hell yes they should be independent. I would be utterly ashamed of the US for invading a Florida that did not want to be invade.
I said it in a different comment: one side drives the other to Long Island. Both sides continue to say they are the US, neither wants to sign a peace treaty or even armistice, both sides want and claim the other's land. They don't say they're independent, they say they are the US. And in this case Long Island controls yoursea access and is supported by a hostile country. Remember the war never ended, neither side signed or wanted to sign shit. What now? Who gets to decide? Do foreign countries get to decide?
People today are still obsessed with the civil war and fly Confederate flags, and that shit was actually settled and a long time ago too. China's is much more recent and still relevant. See my other comments.