The USA had a Civil War that resulted in the deaths of hundreds of thousands of people when a number of states left the Union to form a new country.
China views Taiwan as part of greater China, just like we view Hawaii and Alaska as part of the USA, we would not tolerate either one leaving the Union and would resent any foreign country militarily supporting them breaking away, rightly or wrongly, China feels the same way.
With all due respect, I think that’s a poor analogy. In the case of China and Taiwan, Taiwan is the continuation of the older nationalist government that was overthrown by Mao’s communist forces in 1949 and fled to Taiwan, rather than a breakaway region. If anything, it’s the CCP that broke away from the nationalist government that was in power, not the other way around. And it was not done by regions on the mainland deciding for themselves to secede but rather by conquest by Mao’s rebel forces.
I live in very rural Hawaii. I’m darned sure that as long as the USA still had Pearl harbor and the airbases they could care less what the rest of Hawaii did.
There is only 200,000 people on my island which is the size of Connecticut.
My last home in WA state, King county had more than 10 times that population. there I lived in a part of the county 33 miles East of Seattle.
there we had over 950 people per sq mile, here we have less than 50.
The USA would not miss Hawaii other than its military value.
Full disclosure;
I’m proud to be an American citizen and disabled Veteran,
but on the grand scheme of things we are just a fly speck.
Taiwan was part of Japan until 1952. Had nothing to do with China’s civil war.