Diplomacy in Invention of a new character system in Asian history.

  In the history, Asian kingdoms around China invented their own characters when they were strong enough to cope with China, e.g. the Mongol Empire (which occupied the whole land of China), the Chin Dynasty of Jurchens(女眞族), the Liao Dynasty of Khitans(契丹) (both occupied the northern half of China), and Korea, which expanded the territory a lot by occupying Chinese territory when the King Sejong invented Hangeul.
  Mainly it's because Chinese dynasties had considered the inventions of their own characters of other kingdoms as a critical challenge to China. So invention of a new character system had important diplomatic implications.