Sadae

Sadae is a neutral Korean term. It is used in historical contexts. The term is used as a descriptive label for diplomatic relations between Imperial China and Korea during the Joseon period and earlier. 
"Sadae" describes a foreign policy. It describes the many ways a small country acknowledges the strength of a greater power like that of China. 
For example, "Sadae" is shown in the actions of the weaker state as it conveys goodwill and respect through its envoys. 
The term "sadae" is also used to explain Korean diplomacy before the establishment of the Joseon kingdom.
History.
The historical term is derived from the Chinese "shi da" (Korean, "sadae") as used by the philosopher Mencius. "Sadae" literally means "dealing with the great" or "serving the great." 
"Sadae" establishes a framework with China as the center of a Confucian moral universe.
"Ssadae" is contrasted with limited trade relationships with other neighboring countries such as Japan.
The concept of "sadae" was rejected by Korean nationalists in the 20th century.