First of all, you can't begin to compare China and Afghanistan. Afganistan has no chance of being a great power, ever. Their only prospect to have the population more fed or less fed, better educated or less educated, and that's about it. They can't win the game, so why try. The same stands true for most countries, aside for a few superpowers. Canada, for example, will be a vague memory three hundred years from now. Should it bend over backwards for the potential to last three hundred and ten years?
Hell, at least Afganistan backwardness is noble. Futile, yes. Harsh, yes. But the sheer stuborness with which the ancient, tribal ways cling to society is heroic in a way.
I'm glad you brought up China, because it's a pretty good example of the opposite. Take the phrase "China has adapted in order to have access to more power, wealth etc". So, China does A in order to accomplish B. However, if you take "China" to mean more than just the geographical location, and take it to mean the sum of the culture, heritage, history, religion, architecutre, social order and so on of the Chinese civilization, then much of "China" has been destroyed or forgotten in the process of modernization. In that case, A did B to accomplish C, but in the process A is no longer A, so the whole equation is meaningless, and A has failed to accomplish its end because of its means. Get it? The world's oldest civilization swallows itself up in order to build more identical skyscrapers and luxury cars by German and Italian designers. Yeah, great trade-off.
Though I'm not so certain about China's break with its history. There's a good chance that what happened in Russia will happen in China. Communism loses its appeal, both practically and as a world view, so something must fill the gap. When the USSR collapsed, people flocked to the Russian Orthodox Church which had not exactly been popular during the days of socialism. They embraced their heritage as a nation because the socialist outlook, the "Worker's Utopia" and "Worldwide Revolution" had lost their appeal. China is, in practice, a capitalist counrty, and in order to maintain social cohesion in the mid to long term, the Chinese government may find that nationalism is a better motivator and uniter than socialism. China has a rich, vast history to fall back on, and is one of the few places on Earth that can claim both a glorious past and a (potentially) glorious future.