So, Africa seems to be neglected a lot in Alternate History, so I am going all the way with this one.
Now, of course I am not thinking of any country in Africa being a superpower akin to the French, British, or Spanish Empires of yore, the USSR/CCCP if not too long ago, the USA of now, or Chin of the future. What I am talking about is an African nation which is considered a great power in the world somewhat along the lines that France, Germany, or Japan are considered now. That, and a definite regional power, one that few in the continent can rival.
My idea is this:
What if after independence, a number of the former French colonies in West and North Africa form an economic and political union, developing along the lines of the European Union, except that some time in the late 1980s, this union creates a fully-fledged democratic nation which begins an economic revival akin to Deng Xiaoping's reforms in China. Thus, after decades of culmination, a "West African Alliance" takes place as a guaranteed regional power on Africa, a global great power, and has the possibility to compete with the People's Republic of China for superpower status. Now, the question is: can it work?