Currently serves as a Senior Fellow at the American Enterprise Institute, where his areas of research are U.S. foreign affairs and national security policy. He is the former U.S. Permanent Representative to the United Nations, as appointed by President George W. Bush. He has also served as Under Secretary of State for Arms Control and International Security, Assistant Secretary for International Organization Affairs at the State Department, Assistant Attorney General at the Department of Justice, and General Counsel for the U.S. Agency for International Development. He is widely considered to be a possible Republican candidate for the 2012 Presidential race.