Has anyone claimed Nigeria yet? While WWIII was being waged between the world's geopolitical giants, MASSOB established Igboland as a sovereign nation. 

They would have needed support to pull this off, however. Perhaps they offered China critical crude oil reserves in exchange for military hardware and other commodities paramount to the crafting and maintenance of a state.

Nigeria might've been unable to really do anything about the "Igbo Secession Crisis" due to the economic stupor that the world was probably in during the Third World War.