Not long.
China was weakened at the beginning of the last century because of its closing of borders - thinking that she has already got everything her people need. Leadership problem! Before that, China was the strongest country in the world because of her more advanced technology ("advance" is always a comparative term.)
At the beginning of this century, China is the world's fastest growing economy AND continues to reduce her population through tight (although unwelcome) birth control. (Compare with India for example who will be continuously hindered by its population demands.)
While education levels in China is still small compared with developed countries, China produces more PhD in science and technology than USA. It is just a matter of time for China to become more inventive and catch up in its scientific and technological achievements.
I based on these two observations to draw the conclusion in the last paragraph:
1. People in USA are still blinded to believe that there is a GOD. (See Polling Data on Science and Religion) Bible is just a fiction, written by some "men" centuries ago (may be with motivations unknown to us today). Even the Pope will get sick and ill. Only medicine can help. Prayers will not do anything. The real miracles are SCIENCE.
2. The urge of Chinese people to get education.
USA policy continues to drain the wealth of its people into a few rich people's pockets (Listen to some of speeches by Noam Chomsky, e.g. the world after Iraq invasion). Bad health care system (see Michael Moore's moive SICKO).
Welcome to the China Century.