Comparing Chinese and USA is not the same as German and Roman

Chinese and USA can't be compared on the same scale because of their fundamental difference in social system. USA being a legal system dominated efficient capitalism, while China being a shallow socialism but deeper feudalism dominated faked capitalism. There is really nothing to compare between the two. USA is in a higher echelon. You can compare European union with USA, that's a better comparison, but not between China and USA.

China's rise should not mean USA's demise. Quite contrarily, smart people in USA already realized that China's rise is in every way beneficial to the well-being in USA, for example, footing all the bills and debt in the US, sharing most of the inflation woes from the USA. Knowledgable people are seeing China as the biggest opportunity that USA has for this century. China and USA will rise together, rather than, one rise and one die scenario.