Medical doctor, specialized in tropical medicine and epidemiology. Involved in humanitarian action since 1977, he has been on numerous missions, mainly in contexts of armed conflicts and IDP situations. President of Médecins sans Frontières from 1982 to1994, he has taught at the Humanitarian and Conflict Response Institute (HCRI) at the University of Manchester (UK) and at Sciences Po Paris. He has published several books and articles, including "Guerre humanitaires ? Mensonges et Intox" (Textuel, 2018), "La Médecine Humanitaire" (PUF, 2010), "Penser dans l'urgence" (Editions du Seuil, 2006) and "Utopies Sanitaires" (Editions Le Pommier, 2000).