District of Tumenjiang,or Tureen river areais described by JapaneseTakeo Touma as strategiccenter of \"Japan Sea RimEconomic Zone\" for fiveeconomic regions (Japanthe Far East region ofRussia, North and SouthKorea, and the North-east region of China).As the typical exampleof international regionalcooperation, the idea ofTumenjiang area devel-opment has lasted fornearly 20 years with thefluctuations of interna-tional politics.