The US protected Taiwanese sovereignty for decades before they even had a single semiconductor fab. This idea of "the silicon shield" just shows a complete ignorance of the history of Taiwan and its place in the geopolitical order.
Decades in which China started as peasant army(US admin view) and wasn't mostly a peer adversity. But, that changed almost a decade ago and defending Taiwan will become more costly and time passes. New American security document, mostly focusing on America, even acknowledges this.
Trump has openly stated that there would be no military retaliation by the US in case of a Chinese invasion of Taiwan. Only an economic one. And we have seen what that is worth after the Krim was taken. It lasted a few years and then sanctions started getting dropped.
So the time of military US protection is behind us.
I believe you mis remembered it. He didn't rule out military intervention.
In an interview reported by Reuters, he said he’d impose 150%–200% tariffs if China “went into Taiwan,” and when asked about using military force against a blockade he said it “would not come to that” because Xi “respects me” and knows he’s “crazy.”
