Paul Kennedy in The Rise and Fall of the Great Powers (1987) answers:

Of all the civilizations of premodern times, none appeared more advanced, none felt more superior, than that of China. Its considerable population, 100-130 million compared with Europe’s 50-55 million in the fifteenth century; its remarkable culture; its exceedingly fertile and irrigated plains, linked by a splendid canal system since the eleventh century; and its unified, hierarchic administration run by a well-educated Confucian bureaucracy had given a coherence and sophistication to Chinese society which was the envy of foreign visitors. (p. 4, p. 6)

An interesting thing about this book is that Paul Kennedy predicted that Japan would overtake America. More than two decades on, we all know that he was wrong. And he admitted his miscalculation in a March 2010 interview, in which he predicts that in the future, there will be no one single world power. This argument is strikingly similar to Nicholas Ostler’s about the future of lingua franca.

Kennedy says in the interview:

I can see in possibly 25 years’ time, you have got — you have got a U.S., you have got a Brazil, interestingly, coming up fast, you have got a China, you have got an India, and a possibly consolidated E.U., and you’re looking at something like Metternich’s Congress of Vienna system, a concert of big powers. 

The transcript of the interview is here.