Over the last 350 years, nation-states have interacted via international norms and institutions that were nurtured under the principles of Westphalian nation-statehood. In the aftermath of the Second World War (1939-1945), the U.S.-led West created an international system based upon the interactions of developed nation-states. New nation-states formed in colonial lands when their European overseers departed. These new nation-states tried to adhere to the Westphalian ideals, but many of them were nation-state in name only. The controlling entities were not the nationstate's governing bodies; the controlling entities were the tribal societies beneath the surface. Great powers have continued to work with these hollow governments and/or tribal societies with little to no success. In order to achieve positive policy results, great powers must adjust their interactions and expectations when dealing with tribal societies and/or weak nation-states.