China was, after all, the Middle Kingdom, whose emperor ruled by the Mandate of Heaven. It was big enough and rich enough to ignore and snub the outside world. The Chinese grew all the food they needed and produced all the luxuries (porcelain, silk, jade) that its most privileged citizens required to adorn their palaces with an opulence of which the monarchs of Europe could only dream. China also saw itself as too big and strong to subjugate and colonize.
