When the publishers approached the authors about the possibility of a second edition of this book, Theo Farrell and Hélène Lambert decided that they had too many other commitments to devote the necessary time to this so David Armstrong is the sole author of all changes from the first edition. My initial proposals were to update all chapters and also add more information about a variety of topics, including the non-state actors, institutions involved in the development and application of international law, such as the International Criminal Court, and to take more account of Chinese, Islamic and developing countries’ positions. I also suggested that our original concluding chapter, ‘International law in a unipolar age’ had somewhat been overtaken by events to the extent that a new title, ‘Law and power in an evolving world order’ might be more appropriate – at least in enabling me to indulge in some speculations about a future where the US might be less dominant than it has been in the last two decades. My final proposal was to devote more time to the concept of an international society. Theo Farrell, as a leading Constructivist, was the principal designer of our original theoretical framework and, as he was less enthusiastic than me about the ‘English School’, it was only allocated a few sentences in the first edition. I have seized the opportunity to rectify that omission. It is also true that in some other cases I have probably expressed views that Theo and Hélène would not necessarily concur with, so responsibility for them is mine alone.

The publishers invited three anonymous scholars to suggest any additional changes they would like to see and, so far as possible, I have tried to incorporate their valuable proposals. The authors were very pleased that all three said they and their students found the book very useful. The scholars’ specific suggestions included expanding the discussion of the law of armed conflict and international humanitarian law, adding a section on ‘responsibility to protect’ plus something on soft law and including a bibliography and I have taken account of all those proposals, so I am the sole author of all changes.