Kessler graduated from the Instituts d'études politiques in Paris, specialising in the study of public service.

[1] She then obtained a Doctor of Law degree in 1967,[2] and in 1983 she earned a PhD in political science.

[1] Kessler spent much of her career as a researcher in political sociology and administrative science at University of Paris II Panthéon-Assas.

She explored these topics in multiple books, including Le Conseil d'État (The state council) in 1968[4] and Grands Corps de l'Etat (The Grand Corps of the State) in 1986.

Acteurs et processus (Foreign policy in France: Actors and processes) in 1999,[6][7] and Les Ambassadeurs (The ambassadors) in 2012.