Another reason is the sovereign-vassal relationship with tributes between Chinese dynasties, great empires, and surrounding countries based on Sinocentrism and Suzerainty, that brought economic exchanges and a certain stability of diplomatic orders to East Asia.
さらに巨大な帝国だった中国諸王朝が中華思想、華夷秩序に基づいて周辺諸国を冊封して朝貢関係を築き、それが経済交流と外交秩序の一定の安定を東アジアにもたらしたことにもよる。