From a moral standpoint they have nothing on Taiwan, but hey Ukraine can say the same about Russia for the Donbass too.
Moral standpoint doesn't matter. Ukraine has land connections with NATO, Taiwan has land-connection to nothing. All that matters is how much strength you have in hand. Ukraine has some strength due to Nato, Taiwan has zero.
So US has a de facto beginning part scale invasion, and therefore can also surrender the threat/retreat by negotiation
Negotiation requires willingness, understanding of the current situation. Keeping Taiwan away from China is far too significant for the American Empire to simply negotiate away. So the only way they negotiate it away is only if China "convinces" them to do so. Peacefully of course..
It's realpolitik and of course China wouldn't stop at just rolling back the US threat in Taiwan. It is just the first step.
Which is why US can't simply willingly negotiate it away
Not in our direct control but we can mess up US a lot by starting a conflict somewhere else, making it impossible to annex Greenland.
Why do you think it's impossible for the US to annex it? And why should China gift such a perfect opportunity to the US by making trouble somewhere else and thus drawing world's attention away from US imperialism?
No, China should not do anything other than making a huge tours all around the world and loudly portray the US as the next Nazi Germany looking to expand and conquer more countries. Let them all panic and fear for their lives.
The greatest victory is not only winning without fighting. Not only winning with just asking other people to do the hard work.
No, the greatest victory of all, is winning by other people begging you, coming closer to you, and competing between themselves on who will do the dirtiest work to please you, without you even telling them a word. That's the greatest victory, and that's the situation that all emperors and monarchs through history liked the most.
So for this reason, I wholeheartedly support Trump annexing Greenland, Panama and Canada or whatever other country he wants. I also really hope he increases threats and his bombastic, threatening and imperialist rhetoric