Should the US commit to defending Taiwan?

[Beet]

No, baiting a nuclear-armed power into a shooting war is insane. Like it or, the US has pursued a policy of "strategic ambiguity" for half a century. We do not have a defense treaty with Taiwan like we have with Japan or the NATO countries. Which puts it in the same basket as Ukraine. I do not condone wars of aggression, of course, but trying to stop China (or Russia) from invading one of their neighbors would lead to a nuclear exchange. How can anyone seriously contemplate that?

it would only lead to a nuclear exchange if Russia or the PRC initiated it.  How could either of them seriously contemplate going to war with the greatest military the world has ever seen?  Just so they can invade a weaker neighbor?  No chance.  They aren't suicidal.

And arguments such as yours are the same arguments cowards make when dealing with terrorists.  Which is why you never deal with terrorists.  Threatening nuclear war if you don't get to invade your neighbors is terrorism.

They wouldn't want to initiate it, but Xi may feel it's a choice between that and him losing power, which would happen to any Chinese leader that was seen as capitulating on TW. In that case, he'd choose war.

[Beet]

Accepting the principle that nuclear-armed states can invade their neighbors with impunity functionally guarantees that nuclear war will happen sooner or latter. Just like accepting Hitler's invasion of Czekoslovakia functionally guaranteed WW2.

The only way you actually stop it is by putting your foot down and saying "try me".

So the only way to stop nuclear war is to get into one? Makes no sense.

Taiwan is not Ukraine. Ukraine is an internationally recognized U.N. member state, including recognized by Russia itself until 2014, with its 1991 borders. Taiwan on the other hand is not recognized by any but a handful of tiny countries and has not even declared its own existence except as the Republic of China (ROC), let alone ever having been recognized by the PRC. So there are huge differences in principle between that island and other neighbors that are actual states.

Further, there are things we can do to defend Taiwan and deny "impunity" without getting into a direct war with China. We can impose economic costs like prohibiting Chinese exports which would cripple their economy, sanctions, and providing weapons and other aid to Taiwan that would make the attack prohibitively costly.