Then you only half agree with John. He insists that Communist China is no threat to Taiwan, either (not in this thread, but in many, many others).
Your projection of China's threat to America puts the country in a heap of trouble smack dab in the middle of my baby girl's (and her family's) lifetime. That scares me as much as any immediate threat.
The only way to eliminate all foreign threats to the US is to eliminate all foreign nations.
My estimate: all things being equal (which they aren't), China is not going to be a serious threat to US interests before 2030 at the earliest. However, China isn't going to make it past 2015--they are Enron with a nuclear arsenal and huge social problems looming as a byproduct of one-child-per-family.