[InkCanon]

I am reasonably familiar with it, you're missing mentioning why the US defended Taiwan initially. The US stopped any formal defense of Taiwan in 1980, not to the 1990s. During the period it did have a defense treaty it was within the context of creating an anti communist bulwark, and such defence treaties (even with highly suspect partners) was the bread and butter of geopolitics in the Cold War. It was not because of some deep love of Taiwan or democracy, in fact Taiwan would only become a democracy after the defense treaty was terminated. And "ardent supporter" is a very tricky term, the US signed a declaration for the One China policy, which is completely against the idea of Taiwan as a separate nation(although at the time the KMT and people largely did not view Taiwan as an separate nation).

The silicon shield is undoubtedly a significant part of the calculus around Taiwan, especially wrt direct military intervention. Successive administrations have clearly shown their emphasis on maintaining access to key strategic resources (the Middle East and oil).

[eloisius]

What One China policy did the US sign? China has a One China Principal which some countries uphold, but the US is not one of them. Our _policy_ is to acknowledge China’s position but does not endorse or challenge it. Chinese diplomats are eternally trying to conflate the two, saying even the US admits there is but one China, and thus supports China’s position on the Taiwan question, but that is not true.

As for the silicon shield, yes it’s probably a major factor, but not close to the only factor. If PRC realizes its claims over Taiwan and the South China Sea, the entire region, including many US allies, will be under Chinese hegemony. It would spell the end of the current economic order. Japan, Philippines, basically all of East and Southeast Asia would then be trading within China’s new backyard.

[Tier3r]

If one gets into the weeds of the whole messy thing, the Shanghai Communique acknowledges the position of both sides (Taiwan and China) that there is one China, the 1982 Joint Communique acknowledged the Chinese position and said the US had no intention of pursuing a "two Chinas" or "one China and Taiwan" policy. And of course there's a non stop stream of such political speak, which is a red herring for the whole issue. Beyond minor changes to wordings, the main things the US did that screwed over Taiwan:

1) Revoking the mutual defense treaty which legally bound the US to defend Taiwan, replacing it with a more vague law where military intervention was not clear. 2) Recognizing the PRC as the legitimate representative of China.

To align your claims slightly, Taiwan also claims the same section of the SCS (actually it claims a slightly larger part), so strictly speaking it is what happens if the "Chinese claims" are realised (Taiwan and China work jointly to support their claims, ironically enough). In real terms the economic effects of China with respect to the SCS are greatly exaggerated for a number of reasons. First being that shipping can be routed through Indonesia. It is not a chokepoint, it just happens to be the shortest route. Second, blockades have little to do with recognising swaths of ocean as territory. These are enforced by navies, and most blockades in history have not happened within the blockaders' own waters (for obvious reasons). It is no easier for China to blockade trade in the region if it claims the SCS. And third, of all the major economic powers, China has historically been the least likely to enact economic warfare like blockades or sanctions. There is also a fourth aspect where in the current political environment, the globalised, trade based economic order is the least popular in the US and assorted European states, not China (who in fact desperately needs trade).