"Also the bases in Djibouti and Senegal are strategically place to protect US oil interests. Djibouti is located at the narrow Bab el Mandeb Strait at the entrance of the Red Sea, at the "world's busiest shipping lanes and close to Arabian oilfields," according to the CIA. Senegal, at the West African coast is strategically placed in a region with intensive oil explorations, which the US hopes may become a new major oil supplier within some years."
http://www.afrol.com/articles/14269