not to mention their advances in astrology, weaponry, fine clothing, war tactics etc. The Chinese made ships that would embarrass anything the Western world was capable of making for centuries. Their political culture isn't particularly suited for a modern world, which is why they have done so poorly in the last few centuries, but as someone else said, these folks have been around as a cohesive society for thousands of years. A few hundred years of playing second fiddle to a Western upstart, such as the United States, is but a blip on their radar screen.
I am not convinced they have what it takes to challenge the United States in the future, politically and culturally, but the US isn't necessarily maintaining any of the political values that made us great (federalism, constitutionalism, individualism, liberalism in its classic sense, etc.) If you just look at how our leaders, the media, and our political cousins, the Europeans, have responded to Islamic bullying over the cartoon incident, I wouldn't say we're necessarily beaming with confidence over our own values as a culture.
And it is said, those who have no confidence in their culture, have no reason to defend it.
They built a Great Wall...but was that to keep others out or keep their own people in?
What you are arguing is factually correct, but a little miss leading. In 476 AD China was not the home of the worlds leading civilization, Rome (Europe, middle east, north africa), and maybe India too, were all more advanced. But then Rome fell, muslims ravaged most of the western world and progress in the west came to a halt for close to 1000 years. China largely escaped, (yea monguls were a b*tch) but for most of that 1000 years their civilization remained largely intack. When civilization returned to Europe 13, 1400's Europe once again became home to the world most advanced civilization(s). Why? beats me, but that's the way it's been going since day one.
China has the patience to sit back and wait for the US to destroy itself from within. One that happens they'll be sitting pretty for world dominance.