I think realistically the US is unfortunately never going to protect Taiwan. There's no way I see it getting into an unwinnable hot war with China over territory so close to the mainland. If China sent troops to secure the Taiwanese fabs, how could the US possibly dislodge them without destroying the thing they want to protect? The focus on the CHIPS Act by both recent administrations seems an admission that they don't expect to rely on Taiwan's production long term. The question is will China sit back and let TSMC complete factories in the US, or will it invade Taiwan first? I've seen estimates that Beijing expects to surpass Taiwan's fab abilities in as soon as five years, so perhaps they don't even care about the US acquiring expertise that will be obsolete by the time it is built. Hopefully a knowledgeable individual can correct my extremely limited understanding of this issue.
> how could the US possibly dislodge them without destroying the thing they want to protect?
I would instead assert that it is very likely that the US would destroy the fabs rather than allow China to gain control of them through an act of aggression.
The doctrine of mutually assured destruction has been around a long time. The international players are familiar with it.
I highly doubt it. Taiwan would destroy their own fabs before someone else did. But that's likely unnecessary, China would be unable to operate the fabs anyway and they've already stolen the relevant information and are trying to recreate it. TSMC would get their experts out of the country and their trade partners would simply stop supplying the vital materials.
And mututally assured destruction has nothing to do with the US destroying an industry in Taiwan. MAD specifically refers to the idea that superpowers cannot engage in nuclear war against one another without also being destroyed themselves, because of a Nuclear Triad.
For "Mutually Assured Destruction" to be in anyway applicable, you'd have to say that the second that the US destroyed "Chinese" fabs (Taiwan), China would destroy American fabs. Thus, the US would not attack China without risking itself. The US making targeted strikes on Taiwan is one sided destruction. But to be clear: MAD doctrine is specifically about fullscale thermonuclear war.
China would not engage in nuclear escalation in response to the US striking Taiwan, and China does not otherwise possess the ability to strike the US homeland without incurring a nuclear response, so there is no mutually assured destruction with regards to semiconductor industry. In this hypothetical, the US would succeed in striking Taiwan and China would not escalate into nuclear war. But, the US would not strike Taiwan. Taiwan would destroy their own industry before that happened.
The current U.S. leadership is so chaotic and seemingly uninvolved in strategy that predictions about whether/how MAD would play out are difficult to make.
All the best to war games seem pretty bleak given the relative salience of the issue between US & China.
Being a small island it’s much more of a zero sum / all or nothing fight than say Ukraine where at some point they can agree on a line on the map for Putin to walk away with a territorial partial win.
Lot of headwind for US between ship building, distance, whether Japan allows usage of bases, total manpower, Chinese ship killer missiles, authoritarian dictatorships willingness to throw manpower into meat grinders, etc.
Not that it’s a slam dunk for China either - beach landings are hard, and their war machine is largely unproven.
The most likely outcome is Taiwan or US destroy the fabs in event of invasion.
