In South Sudan, Mass Killings, Rapes and the Limits of U.S. Diplomacy
UNITED NATIONS — Samantha Power had just boarded a United States Air Force plane on her way home from a three-country tour in Africa when the calls began to come in from Washington. South Sudan, the world’s newest country, had just erupted in civil war along ethnic lines. That was in December 2013. Ms. Power had taken over as…