I think the disconnect between us is that you think that I am arguing an objective legal case and I am merely arguing a realpolitik one with the selfish interests of America as my north star.
I agree that China is intent on replacing America's (relatively benign) global hegemony with a more hostile Chinese global hegemony. But, beyond Taiwan, I don't think that includes implementation of that hegemony by military force over other sovereign nations assuming a continued strong US military presence in Asia. I believe that Taiwan is different for mainland China (not just Xi or the CCP, but a very large portion of the mainland Chinese people) due to common ethnic heritage, the non-indigenous history of Taiwan, and the lineage of the current Taiwanese government from the "losing" side of a civil war.
I am not blind or unsympathetic to the real world endgame of my view. But that doesn't change my view of what I think is best for the United States and, frankly, the rest of the world. And with absolute certainty there will be red lines that have to be clearly drawn and defended with the PRC in the coming decades. But Taiwan is very personal to them, and that raises the stakes immensely for serious miscalculation between the two heaviest hitters on the planet. That's not a sitiuation where I would choose to die in a ditch on right or wrong.
I heartily acknowledge that I could be wrong.