Since May 2005, he has been a contributing blogger at "HuffPost". He is a member of the Council on Foreign Relations. Hart also sits on the Advisory Board of Operation USA, a Los Angeles-based international relief and development agency. It was announced in January 2006 that Hart will hold an endowed professorship at the University of Colorado. He is the author of "James Monroe", part of the Times Books series on American presidents published in October 2005. Hart is an Honorary Fellow of the Literary & Historical Society of University College Dublin. He is an Advisory Board member for the Partnership for a Secure America, a not-for-profit organization dedicated to recreating the bipartisan center in American national security and foreign policy. He is also a member of the ReFormers Caucus of Issue One.