No large power recognizes Taiwan as sovereign country, not even US. The largest country that recognizes Taiwan is Guatemala.
I don't see how it is out of the question that China just sails to Taiwan and takes it while everybody else stands and watches.
Recognition isn't nothing, but concrete support without recognition is more valuable than the reverse.
Hint: the sales are probably not to make money.
- Crimeans are predominately Russian speakers and so the annexation was somewhat popular. Very little bloodshed or ongoing resistance. An invasion of Taiwan would not be popular among the Taiwanese.
- Crimea and Ukraine are geopolitically not very useful. Taiwan is extremely useful, especially if it allows defense access to e.g. American warships.
- Crimea is mostly a resort economy. Taiwan is the center of chip production.
A large reason for the annexation of Ukraine was the question of control of Russia's only warm-water seaport at Sevastopol. I doubt Russia would have bothered (given the international consequences, i.e. sanctions and potential military intervention) if their access to the Black Sea wasn't threatened by Ukraine's increasing ties with the West.
Ultimately Crimea is of limited strategic value for anyone other than Russia. The same cannot be said for Taiwan.
This is the same reason why Russia got involved in Syria, it has only a handful of warm water ports and essentially all of them are at a precarious position where they ship need to traverse potentially hostile choke points.
Also US political ties to Taiwan are far stronger than to Ukraine these date back to WW2 and even earlier technically.
People say US will save Taiwan from China? I call bullshit. If that was true US should have no trouble recognizing Taiwan which would be hopefully be start of the process of getting legitimacy Taiwan needs.
I fully expect US to do nothing if China invades Taiwan.
Mark my words.
https://en.wikipedia.org/wiki/Republic_of_China_Army#Equipme...
However if for whatever reasons China would go full scale on Taiwan I doubt the US would respond in kind. There is just too much risk of conflict turning into WWIII. The West may try to isolate China instead.
More likely the US (and West) would attempt to punish China economically for its behavior, though I have a hard time believing that would work either. Even if an agreement is later reached and sanctions lifted, I doubt Taiwanese independence would be a part of that.
Unless there is a huge shift in sentiment toward Taiwan in China's leadership, I am really afraid that it's inevitable that Taiwan ends up being taken by force at some point in the not-too-distant future.
Now, in the real world, that claim plus six bucks will get you a latte at Starbucks. But politically, letting go of it might cost more than any political party is willing to pay. Thus both sides of the straights cling to the "one China" fiction.
A quick look at Wikipedia suggests that (as of 2019), about 49% of citizens supported independence (though 21% believes that now is not the time due to the political climate), with 31% supporting the status quo. Only 10.3% outright support reunification.
In 2020, support for independence increased, to 54%, though support for reunification also increased to 12.5%.
I think it's pretty safe to say that an overwhelming majority of people in Taiwan do not actively want reunification with China. The DPP has never held that position, and the KMT dropping it would surely splinter their supporters[0], though possibly not a majority of them. Obviously on the PRC side of the equation, allowing Taiwan its independence is a non-starter.
[0] Anecdotally, it does seem that KMT support skews older, so I expect new and future generations to continue to lean more toward independence.
Friendships made this way are very weak.