The U.S. Air Force has quietly deployed a number of KC-135s and F-16s to Camp Lemonnier in Djibouti, this was at the request of Africa Command.
By U.S. Air Force photo by Master Sgt. William Greer [Public domain], via Wikimedia Commons
U.S. Africa Command said it was a “precautionary measure in order to protect Americans and American interests in South Sudan if required.”