JD, Georgetown University; PhD in Political Science, Stanford University. Formerly with the National Security Council staff under presidents Bush (Sr.) and Clinton and had a distinguished career in the United States Army. 2003-09, Acting Undersecretary-General for Field Support and Assistant Secretary-General for Peacekeeping, United Nations (UN); concurrently, Assistant Secretary-General for Peacebuilding, responsible for coordinating efforts on behalf of the Secretary-General to build sustainable peace in countries emerging from violent conflict. 2009-13, Deputy Secretary, Department of Homeland Security (DHS); as the Department's Chief Operating Officer, responsible for the day-to-day management of the Department. Currently, Director, Center for Internet Security.