Intergovernmental organizations (IGOs) are conceived as legal bureaucracies dedicated to a specific mandate, according to an optimal division of labour. Despite this ‘rational design’, IGOs do not meet all the standards of Weberian organizations: productivity is low, overlap is high and waste is frequent. Expected to return someday to the domestic administration from which they come, their agents have no career. They are not recruited through competitive examination and promoted according to merit, but appointed according to their social capital.