I like your optimism, but are you forgetting Iran?

> What's looking increasingly likely, though, is that China under Xi will invade Taiwan, and then the US will be in the hard position of having to choose whether it will blink, or back up its pledges to defend the island with action.

It's a very specific scenario. Officially, Taiwan isn't an independent country, the US has no relations with them and doesn't have a pact of mutual assistance or promises to come to its aid. In case China invades what it and most of the world officially consider to be a part of China ( One China policy, almost all countries in the world recognise the PRC as the single China), the US can close its eyes and it wouldn't have violated any treaty or anything of the like, or they can join the war under some pretense.

> The calculus is extra interesting because Xi won't invade unless he thinks the US will blink, a calculus Saddam famously got wrong when he invaded Kuwait.

He got it wrong because the US, and most notably their ambassador to Iraq, shat the bed spectacularly bad leading him to believe he will get away with it. I recommend the Military Intelligence Blunders and Cover-Ups book, it had a chapter on that debacle.