So, by your logic, once weak means always weak. If you lose one fight you will lose all fights. Does that mean that if you win one fight you will win all fights? This is the 21st century mate, wake up. The China you are talking about has changed drastically.
Korea -- that was a humiliating war for the Americans. We sucked at winter warfare like the Germans and the French. The war has not ended, we are only at a cease fire.
* How did the mighty British Army lose the Revolutionary war to a bunch of untrained American colonists? You see the analogy here?