Ethiopia has been at loggerheads with downstream neighbors Egypt and Sudan for years over a $5 billion mega-dam it’s building on the Nile River. A third phase of filling a 74 billion cubic-meter (2.6 trillion cubic-foot) reservoir behind the Grand Ethiopian Renaissance Dam was completed in August, a process that’s reignited tensions. Egypt has described the unilateral action as a violation of international law and its foreign minister, Sameh Shoukry, wrote to the United Nations Security Council in July, reiterating its objections and accusing Ethiopia of derailing attempts to resolve the standoff.