What would you have us do in the event China invades (reunifies, storms with roman candles, whatever..) Taiwan?
You mentioned "vague language" so I assume you are ready to trash our treaty.. And if not, how far would you go to support them? Nuke conflict if the need was there?
Come on, you posted this thread so don't be vague.. don't hide or parse.. We had 8 years of that already.
As long as Taiwan doesn't declare independence, it's very unlikely China will invade at all. The US doesn't want Taiwan to declare independence either because it leads to all sorts of other problems. If the US supported Taiwan's independence, then the US would be going back on its own word. China would invade Taiwan and there would be a war and the US could intervene but will do so having broken its word about not supporting Taiwanese independence.