The risks involved in going up against a nuclear power are very high, the costs involved (both monetary and in lives) would be high, and success isn't guarantee

The risks involved in going up against a nuclear power are very high, the costs involved (both monetary and in lives) would be high, and success isn't guaranteed. I could well imagine Biden consulting with his military advisors and coming to the conclusion that it just isn't worth it. We saw a similar thing play out with Obama and Crimea. The winning strategy for the U.S. right now seems to be to convince China we would defend Taiwan so they don't attempt an invasion in the first place. But that's hard to do when it looks like the U.S. has pretty compelling reasons to stay out of it if it came to that. (This is all assuming that Taiwan asks for our help. I don't know why they wouldn't, but I feel like it's an important caveat that we shouldn't involve ourselves in conflicts we aren't invited into by at least one party.)