Steven Pifer is director of the Arms Control and Non-Proliferation Initiative at the Brookings Institution, where he also works on Ukraine and Russia questions. He is co-author of "The Opportunity: Next Steps in Reducing Nuclear Arms." A retired Foreign Service officer, his more than twenty-five years with the State Department included assignments as deputy assistant secretary of state with responsibilities for Russia and Ukraine (2001-2004), ambassador to Ukraine (1998-2000), and special assistant to the president and senior director for Russia, Ukraine, and Eurasia on the National Security Council (1996-1997). He also served in Warsaw, Geneva, Moscow, and London.