Those in the Japan camp are waaaaaaaaaaaaaaaay too focused on the technicalities You d be hard pressed to find any book that introduces Joseon was a tributary of China or Joseon was a sovereign country nation state No it d more like Joseon was a country in Korea the end So that whole google book page hit is irrelevant And Bill Price is right the English terms are a sort of a cop out I mean surely you wouldn t call the British Empire a tributary of China prior to the Opium Wars Despite this denomination Joseon was and acted as a independent sovereign nation This excerpt explains more about the relationship and how such terms may be confusing