Abstract
This article focuses on scientist-diplomats that are the scientists who serve as national representatives and consultants for discussions on scientific and technical issues in international organizations. We examine two exemplary cases of Mexican scientist-diplomats: Francisco de Paula Miranda and Manuel Sandoval Vallarta, experts in nutrition and atomic energy, respectively. We discuss especially how they became involved as experts in the international arena, and we analyse the feedback process of construction of their scientific and diplomatic authority. Furthermore, we consider the interaction of interests (disciplinary, professional, local, and global) that they represented and negotiated.