“Natural” risks and catastrophes appeared in the international arena in the early 1990s. A real « world » of “natural” catastrophes has emerged internationally and has become more and more institutionalized. This study raises questions such as: how has this space been built? How do actors legitimize its necessity? What does it tell us about the way the contemporary world manages fears globally? A diachronic approach of this double process of internationalization and institutionalization allows the author to situate the phenomenon in the historical and global context, and notably of a context of transformation of the notion of security. The sociological analysis of the main multilateral organizations that contribute to forming this space invites us to apprehend the various lines of tension that cross over, and to foresee its complexity. Despite the many attempts to make this space appear as a “community” of sense and practices, strong disparities characterize the actors’ approaches.