Some of the most glaring differences between States and international organizations are of a structural character. For one, international organizations do not possess territory or a population. In institutional terms, political organs composed by representatives from member States and secretariats composed of international civil servants hardly resemble those of national parliaments and executive branches. International organizations are not only different from States but also from each other. The chapter ponders the extent to which such structural differences affect the applicability of general international law to international organizations, thus justifying departures from an analogy with States.