With no 2nd source supplier the US is in a position to provide strong deterrence against invasion.
The US defended S. Korea for ideological reasons, and it will do the same again.
But even if you're cynical about these sort of things, the TSMC plant in the US will only provide enough chips for DoD usage. It definitely can't support the commercial sector.
Huh? DoD doesn't use any TSMC fabs, they have their own security accredited fabs for that on US shore that mostly cater to US government customers and not much else.
Similarly, TSMC and most other consumer fabs, have no desire to take any DoD contracts in peace time, as the legal and security related paperwork are not worth the huge hassle and low margin prices the government is willing to pay in peace time compared to what Nvidia, AMD, Apple, etc. fork up.
https://www.csis.org/analysis/semiconductors-and-national-de...
What the parent is referring to is DMEA's Trusted Foundry Program[1], of which TSMC is not an accredited supplier of foundry services.
[1] https://www.dmea.osd.mil/otherdocs/accreditedsuppliers.pdf
Conversely, if Taiwan relied on its fabs to incentivize protection, what happens after those fabs get destroyed in the opening minutes of the conflict?
Like the Godfather.
They won't. That's why they are cloning it in the west.
Anyway - the United States places value on Taiwan not just because of TSMC (otherwise why was there value before TSMC even existed) but because Taiwan serves as a key piece in the so-called first island chain of US-allied nations that sit on the eastern coast of China. This includes Taiwan, but also Japan and others.
The reason today that America is very interested in Taiwan is because in the event of a Chinese invasion of Taiwan - American commitment to the Pacific comes in to question. Will the US respond to, and go directly to war with China? If it does, can it win? If it does, what other nations will come to the aid of the US (or China), and who will stay out? The key piece here is that it puts the American alliance system to the test and some (not I) question whether the United States is committed to defending other countries in the Pacific theater if it means a "real war" - i.e. Japan, Korea.
The US already doesn't need TSMC for any strategic purposes - while the loss of the fabs in Taiwan would be devastating to the world economy, America (and other nations for that matter) still produce semiconductors, just not quite as good. You can still build cars with Intel chips, but you aren't building the iPhone 16 with them. It's not an existential threat, though certainly a very bad thing.
Alternatively, if China were to invade Taiwan and the US failed to respond, that would be an existential threat to the United States because it would effectively kick the U.S. out of the Pacific and cause long standing allies such as Japan and Korea to play both sides instead of being firmly in America's camp.
Coming back to TSMC building a chip plant in the US - even if they were to (and they probably will) it won't really diminish or change the Taiwan Question and undoubtedly as part of increasing US defense aid to Taiwan the US is going to want to hedge its bets a bit and have an operational fab in the US so that if a war does break it the impacts are lessened. I don't see this as a change to US Pacific strategy because it's not a fundamental concern.
Hyperbolic? The US not having a wall of ships on China's east coast is not an existential threat for the US.
I'd also say characterizing things as "the US having a wall of ships on China's east coast" is itself a bit hyperbolic itself and taken without context quite meaningless.
One might wonder, well why does the US have aircraft carriers in the region?
Maybe it has something to do with things like China's continued threats of taking over Taiwan, or North Korea's launching of ICBMs into the Sea of Japan?
China’s actions have been equally concerning, the build up in South China Sea is a naked attempt at imperialistic expansion. Its activities on its land borders echo much of the same sentiment. It is a de facto revanchist power.
When an ex US colony Philippines invites the US to set up military bases it is not the US doing it, it’s because Philippines has concerns about China.
When S.Korea and Japan start putting differences aside it’s because they share a common threat perception of China.
Not to mention China’s abhorrent pillaging of technology, export of dystopian authoritarian control mechanism to government, and its human rights violations which you seem to ignore, yeah the US isn’t the problem here for a change. The CCP is an absolute challenge to liberal values it must absolutely be restrained. Taiwan is a small piece of that the game is much bigger.