His is a former Senior Volkswagen Research Fellow with the American Institute of Contemporary German Studies at the Johns Hopkins University and a former NATO-EAPC fellow. His books include Atlanticism for a New Century: The Rise, Triumph and Decline of NATO (Prentice-Hall, 2004); Politics in North America: Canada, Mexico and the United States, with Robert J. Jackson, Gregory Mahler, and Holly Reynolds (Prentice-Hall, 2003); NATO for a New Century: Expansion and Intervention in the Atlantic Alliance (Praeger, 2002); Redefining European Security (Garland, 1999); All of the People, All of the Time: American Government at the End of the Century (Peter Lang, 1998); The Trammels of Tradition: Social Democracy in Britain, France, and Germany (Greenwood,1994); Shepherd of Democracy? America and Germany in the Twentieth Century, co-edited with Cathal J. Nolan (Greenwood, 1992).