To spell it out: countries can support powerful and threatening military establishments even if their overall economy is faltering (the old Soviet Union). They can create problems for the world even if they are extremely poor (North Korea). Sometimes economic dislocation itself can make aggression more likely (post-Weimar rise of the Nazis). Often the attempt to escape poverty can cause environmental disaster. And so on.
What I was trying to convey is how different, both intellectually and emotionally, the phenomenon of "China's unstoppable rise" looks if you're actually here seeing the people in the middle of the process, versus how it must sound if you just hear about it from afar.