By stepping up military support to Nigeria against terrorist groups such as Boko Haram and Islamic State in West Africa, the United States is not only defending the security stability of the Sahel and Lake Chad basin. They also protect major geopolitical, economic and strategic interests in one of the most influential powers on the African continent: Nigeria. With more than 220 million people, Africa's leading economy and key player in the Gulf of Guinea, Nigeria is central to the African strategy of the United States. Washington regards Abuja as a regional lock against the expansion of jihadist terrorism in West Africa. An African giant to stabilize For the United States, Nigeria's stability has become an issue of international security. For more than a decade, northeastern Nigeria has been the scene of deadly attacks by Boko Haram and its dissident branch affiliated with the Islamic State. These...