...
As the leader of the Thirteen Constabularies, Xing Yuanguo could see through the hidden message embedded within the Emperor's orders.
"In peace we shall live, in separation we shall perish."
Furthermore, Xing Yuanguo's understanding of this statement was even deeper than Fang Zhengzhi. He also considered the diplomatic implications.
A powerful empire would accept its smaller neighbours as vassals. This is something that was very common throughout history.
Sometimes, it was because the empire was in its nascent stages and had other pressing issues to settle. Other times, it was due to a stark difference in cultures, and the Empire wanted to ensure peace and relative uniformity throughout its citizens.
The relationship between the Southern Region and the Great Xia belonged to the latter.
Culture and beliefs.
