Drawing on his experiences as U.S. special envoy for Sudan and South Sudan, Ambassador Princeton Lyman will highlight the decision making tradeoffs he and his colleagues faced when they weighed the risks associated with the various forms of intervention they considered to mitigate the mass atrocities in Darfur. He will also consider similar tradeoffs raised about the genocide in East Pakistan in the early 1970s and the decision to intervene in Libya to prevent a mass killing in 2011. He will conclude by considering the roles that diplomacy, political pressures, and other factors play in the decision-making process, drawing from his recent study for United States Institute of Peace on “The Effectiveness of Special Envoys in Conflict Situations.”