The five-year-old civil war in South Sudan is an unparalleled humanitarian and security crisis, causing the largest exodus of refugees on the African continent since the Rwandan genocide and leaving over a third of the population displaced and two-thirds severely food insecure. Beyond the human toll on South Sudan’s long-suffering citizens, the country’s unraveling underscores the shifting political and security fault lines in the Horn of Africa. This Special Report surveys the region’s various interstate…