uhhh maybe you need to look into what all Taiwan exports to us and how much American investment has goine into Taiwan before you just write it off.
Okay, I know that it is the usual tyrant line that some other nation "once belonged to us" (Hitler with Austria, Hussein with Kuwait). But it's pretty clear that Taiwan was, and probably still is, part of mainland China. China just decided to get their own house in order before trying to reestablish order in Taiwan (boy, communism works so well that it takes sixty years!).
There is a reason that the United States and the United Nations does not recognize Taiwan as an independent sovereign nation. Just as retaining what is our's was one of several reasons we fought the Civil War, China does not believe Taiwan has the right to secede and perhaps is justified in trying to reclaim it.