The document summarizes the conflict between Sudan and South Sudan over oil resources and territory. After South Sudan gained independence in 2011, conflict erupted over oil transportation fees and the disputed border region of Abyei. Fighting has involved clashes along the border, air strikes, and occupation of the oil town of Heglig. International mediation efforts have struggled as both sides accuse each other and domestic rhetoric stokes nationalism. In September 2012, the presidents of Sudan and South Sudan signed agreements to resume oil exports and create a demilitarized border zone, but issues around Abyei remain unresolved.