[1] He completed his doctorate in political science in 1979 at the WISO Faculty of the University of Cologne with a thesis on the European Council.
[2] In 1990, Wessels was awarded the venia legendi in political science by the University of Bonn[3] with a thesis on the opening of the state.
[5] He served as a visiting professor at the European University Institute in Florence[6] and taught at the Institut d'e'tudes politiques de Paris (Sciences Po Paris) as holder of the Alfred Grosser Chair.
[7] He regularly teaches as a visiting professor at the College of Europe in Bruges and Natolin,[2] as well as at the European Online Academy of the Centre international de Formation Européen (Nice and Berlin)[8] and at the Diplomatic Academy in Vienna.
Since his student days, Wessels has been involved in civil society associations for the unification of Europe - first with the Jungen Europäischen Föderalisten and later with the Europa Union Deutschland.