I agree. The emperor who replaced Zhu Di was more conservative and thought that China should close its doors. He famously said that "The outside world had nothing to offer China, it is too primitive and backwards, leave it alone." This inward looking mentality, fueled by the belief in your own superiority, is the disease of great powers. I am afraid that in some ways the United States has become one, maybe it's a good indicator of a power in decline.