Good question. And same question that has been around since October 1962 that no one can comfortably answer.
Would you? And if you blinked at Taiwan, would you at the Australian invasian?
In fairness,
@catfish1957 , you were the guy who said Taiwan was "different" than Ukraine because we had a treaty, and I was just pointing out that it really isn't different because the treaty with Taiwan doesn't obligate us to provide military support. That's how this particular discussion started.
But to answer your question, right now I'd say no to Taiwan because I think it would be extremely difficult to defend successfully. I'd say yes to Australia because I think Chinese power projection would suck, and we'd win. Also, we do have a formal, public defense treaty with Australia.
However, all that overlooks that our real goal is deterrence. The more likely it is that China believes we'd defend Taiwan, the less likely they are to attack. And that's why Ukraine and Taiwan really being in the same boat is so important. Because if we're seen as unwilling even to just spend money to defend Ukraine, without committing any of our own troops, how are the Chinese likely to view our willingness to engage in an
actual shooting war over Taiwan and spend not just money, but many American lives? And again, it's worth pointing out that Taiwan would be an air/naval battle, while Ukraine is a land war. So the argument for military stocks to defend Taiwan being depleted in Ukraine is pretty weak.
I also believe that a major factor in deterring China from attacking Taiwan is the economic consequences. How are Europe and the U.S. likely to react to a Chinese invasion? Short-term sanctions, followed by a return to normalcy after a face-saving period because our rich lifestyles are too important to us? Or are we nasty, vindictive SOB's willing to suffer economically ourselves to defeat naked aggression? If the Chinese see us doing the latter for Ukraine, they may think twice about the possibility of destroying their own economy by invading Taiwan. But if they see us fold like cheap suits over Ukraine, they'll likely assume we'd do the same over Taiwan.
This is why I personally view defense of Ukraine and deterrence of Chinese aggression as inextricably linked, and why it truly bothers me when the people we're talking about electing don't see that.