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.
Or at least eliminate (or deter) the ones who make threatening the U.S. a matter of public policy.
China considers us their greatest enemy, and their greatest obstacle to world domination. That and the size of their armed forces should at least be enough to put them near the top of our foreign threat list.