The act further stipulates that the United States will "consider any effort to determine the future of Taiwan by other than peaceful means, including by boycotts or embargoes, a threat to the peace and security of the Western Pacific area and of grave concern to the United States".

The act requires the United States to have a policy "to provide Taiwan with arms of a defensive character", and "to maintain the capacity of the United States to resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people on Taiwan." Successive U.S. administrations have sold arms to Taiwan in compliance with the Taiwan Relations Act despite demands from the PRC that the U.S. follow the legally non-binding Three Joint Communiques and the U.S. government's proclaimed One-China policy (which differs from the PRC's interpretation of its one-China principle).

Obviously, it's not something as strong as NATO but we will definitely get involved.

However the real reason why Taiwan can't either fall to China militarily or re-unite with China peacefully is that Taiwan forms the centre of the "Island Chain Strategy" which is a containment strategy established by the US after the PRC came to power in the Chinese mainland and ROC was relegated to Taiwan.

The Island Chain serves to contain the PLA Navy such that China can't operate as a Blue Ocean navy, i.e operate in international seas/oceans. Additionally it sets up a small number of chokepoints that can be used to completely isolate shipping in/out of China so they will alway be able to apply economic pressure through blockade.

This is the -real- source of tension between China and the "West" (even though it's really just the US/Australia/Japan in this case, China is relatively friendly with European countries etc).

If China was able to do the same thing to the US you can imagine the US would be pretty uncomfortable with that situation too.

Without being able to operate freely in the Pacific China's own nuclear deterrence is less effective as they aren't able to move nuclear ballistic subs without detection outside of the containment. This generally means needing bigger, more capable (read MIRV) ICBMs. Also generally means development of containment busting weapons, namely hypersonic nuclear tipped carrier-battle-group destroying missiles. They need effective nuclear deterrence to ensure their nuclear capability can't be disabled in a first strike. Specifically because their main adversaries are the US and Russia (yes, Russia is traditionally a Chinese adversary) both of which have significant nuclear assets so they need their own to ensure MAD is in place.

TLDR: If Taiwan was to come under Chinese control either by force or peacefully it would break a decades long containment strategy by the US, securing Chinese access to the Pacific for both trade and the PLAN.

But if we're not being sardonic a holes, we should be fighting with a Democratic and free government against an autocratic dictatorship whose stated goals are to restore the 'righteous' historical vision of China as the center of the world (it's even the name as far as what I've read, not a speaker of the language: 中国).

Not only is it critical geopolitically and militarily (as in ability to control important & huge swaths of seal / trade routes), ceding ground or worse not putting up a fight at all, would be the death knell of the push for more liberal governments and more freedom.

As always on any topic of Xi or CCP there are a whole bunch of 'but whatabout america.' It's just tiring.

Wow, not the point. The ability to mass influence foreign markets is the topic of discussion, do stay on point.