Originating from a workshop organized by the Adriano Olivetti Foundation (Rome), in the framework of an international research program on «The Role of American Foundations in Europe (1920s -1990s)», this book aims to fill a gap in the social history of sciences, combining two research approaches, which had been developed as separate fields of analysis: the study of American and European co-operation in science policies, particularly in what concerns the funding of scientific programs, and the role of émigrés scholars in strengthening American and international research. The book is focused on the exploration of the role of the Rockefeller Foundation, in a dramatic period of the intellectual history of Europe, from the perspective of the recipients of grants, in its premises and effects on scientific processes as well as on individual paths and careers. From this point of view, it intends to stimulate the exploration of cross-cultural phenomena, which represent an uncertain dimension between strategy as a project and strategy as a conduct, and are shaped by situations and circumstances as well as by the stream of individual actions.