This new edition considers the unifying legal attributes that span vastly differing inter-governmental organisations, from the UN to the EU. A law of international organisations has become established in certain areas, such as legal personality, powers, membership, finance, and decision-making. In other, newer, areas – accountability, responsibility and democracy – politics is still much rawer, and has not yet been fully converted into legal concepts and principles. As with the first edition, there are plenty of examples of organisations given in the text. Individual organisations dealing with issues such as security, health, civil aviation, finance and trade are scrutinised by way of example, to illustrate how different they can be, but also to show how it is possible to debate a set of legal principles that transcend each institution. This new edition of an established text will appeal to students and academics as well as individuals seeking a legal and political insight into international organisations.