Morningstar started his career with the law firm of Peabody & Brown (now
Nixon Peabody) in
Boston,
Massachusetts, where he practiced law from 1970 to 1981. He then served as CEO of Costar Corporation, and since 1990 as the chairman of the board. Beginning in 2001, Ambassador Morningstar served as a senior director at the global strategy firm Stonebridge International (now Albright Stonebridge Group) On 20 April 2009, Ambassador Morningstar was named to the position of the Special Envoy of the United States Secretary of State for Eurasian Energy. In that capacity Morningstar represented the United States at the signing ceremony of the intergovernmental agreement of the
Nabucco pipeline. He has strongly opposed the possible participation of Iran in the Nabucco project. Morningstar has been a visiting scholar and diplomat in residence at the
Stanford University Institute for International Studies, a lecturer in law at Stanford Law School and an adjunct professor at Harvard University's John F. Kennedy School of Government. On 27 April 2012, Morningstar was nominated for the US Ambassadorship in Azerbaijan. On 30 June 2012, the U.S. Senate confirmed this appointment. He gave a speech in defense of
Free Thought University on April 11, 2013, a day after it was closed by the government of Azerbaijan. In 2014 Morningstar was named director of the Atlantic Council’s New Global Energy Center. ==Personal life==