Description:International organizations are unusual creations: generated by and for their member states, they must also often compete with member states. This complicated relationship leads to some uncertainty in the law, and the legal argument of an organization may often be counterpointed by an equally valid argument from a member state. Aware of this relationship in his comprehensive analysis of international institutional law, Jan Klabbers re-appraises the status of international organizations in this text for advanced law and international relations students.