In 1976, he was elected to the first European studies fellowship at St. Catherine's College, Oxford, and in 1984 he became university lecturer in international relations and Fellow of St. Antony's College, Oxford. He taught at the
College of Europe for many years and was the director of the economics department from 1983 to 1999. He was research fellow at the
Royal Institute of International Affairs (Chatham House) in London where he co-directed a project, together with Professor Susan Strange, on the reform of the international monetary system. He was also the editor of the
Journal of Common Market Studies, the leading journal in European integration between 1980 and 1984. In 1990, he returned home as Jean Monnet Professor of European integration at the University of Athens where he taught until 2017 when he became Emeritus Professor. Between 1998-2001 he was the first holder of the Eleftherios Venizelos Chair at the European Institute of the London School of Economics and Political Science (LSE). He has also held several Visiting Professorships notably, as visiting professor at SAIS,
The Johns Hopkins University in Washington D.C. (1983-4), Pierre Werner professorial fellow at the Schuman Centre of the
European University Institute in Florence (2003-4), visiting professor at
King's College, London (2013-5), and Pierre Keller visiting professor. at the
Kennedy School, Harvard University (2016). Since 2019, he has been teaching at the
Paris School of International Affairs (PSIA), Sciences Po. His non-academic activities include two short stints as special envoy in Washington D.C. of the Greek minister of National Economy (1983) and special adviser with ambassadorial rank to the Greek prime minister (1988). He was later adviser to the president of the European Commission (2005–11) and the president of the European Council (2012-4). Since 2001, he has been president of the board of the Hellenic Foundation for European and Foreign Policy (ELIAMEP), Greece's leading think tank. == Awards and honours ==