This article was published in Genève et la paix, Acteurs et enjeux, Trois siècles d'histoire, Actes du colloque historique tenu au Palais de l'Athénée les 1- 2-3 novembre 2001, edited by Roger Durand, with he collaboration of Jean-Daniel Candaux and Antoine Fleury, Association “Genève : un lieu pour la paix”, Geneva, December 2005, pp. 69-99. English translation (extracts) published in : International Geneva Yearbook, Volume XIX, 2005-2006, pp. 5-15. This article was reproduced here with the editors' kind permission.