The 2010 Kampala Amendments to the Rome Statute empowered the International Criminal Court to prosecute the 'supreme crime' under international law: the crime of aggression. This landmark commentary provides the first analysis of the history, theory, legal interpretation and future of the crime of aggression. As well as explaining the positions of the main actors in the negotiations, the authoritative team of leading scholars and practitioners set out exactly how countries have themselves criminalized illegal war-making in domestic law and practice. In light of the anticipated activation of the Court's jurisdiction over this crime in 2017, this work offers, over two volumes, a comprehensive legal analysis of how to understand the material and mental elements of the crime of aggression as defined at Kampala. Alongside The Travaux Préparatoires of the Crime of Aggression (Cambridge, 2011), this commentary provides the definitive resource for anyone concerned with the illegal use of force.

'Kreß and Barriga have brought together leading theorists, lawyers, diplomats, and advocates to examine every aspect of the crime of aggression, from the definition of the offense to its jurisdictional constraints, from its drafting history to its domestic implementation, and from its relationship with the UN Charter to its relationship with just war theory … No international law library will be complete without these two volumes.'

Adil Ahmad Haque Source: Just Security (www.justsecurity.org)

'The parts amount to a comprehensive anthology on the illegal use of force between states. Given the fundamental importance of the topic of the crime of aggression for the international legal order as a whole, and the leading expertise of the editors and many of the authors, the volumes are indispensable to international lawyers and international relations experts alike.'

Morten Bergsmo Source: Journal of Peace Research

'The Crime of Aggression: A Commentary is an outstanding contribution to the field and provides in-depth analysis that is of value to academics and practitioners alike. … [The book] is already - and will undoubtedly remain - the reference work for international (criminal) lawyers as well as political scientists. It contains contributions by over 50 experts known for their extensive knowledge of the field and its day-to-day intricacies.'

Mayeul Hiéramente Source: Sicherheit und Frieden

'The publication is a remarkable contribution and to those wishing to understand the Rome Stature, its evolution and the crime of aggression in particular, it will be a welcome piece into the library. There were already some books published on the topic since 2010 but this publication is unique both in its size and span.'

Milan Lipovsky Source: Czech Yearbook of Public and Private International Law

'In a nutshell, Crime of Aggression: A Commentary should be the cornerstone volume on the crime of aggression. The editors have succeeded in a risky task: to account for the complexity of interpreting the crime of aggression in a language accessible to a wider audience. The richness of the book lies in the editors’ endeavour to provide the readers with all elements needed to comprehensively interpret the crime of aggression. This work is essential reading for international criminal lawyers and other social scientists.'

Source: Journal of International Criminal Justice

'This two-volume work has been composed and edited by (two patrons of the Crime of Aggression, namely) Claus Kress and Stefan Barriga, the scholar and the diplomat. Both editors have in their respective capacity indefatigably striven for the creation of a robust accountability regime for the illegal use of force. The two tomes that they have put together are, in a way, further proof of their dedication to this ambitious undertaking … It is the great merit of this book to bring all those different issues together, and to do so in such an impressive fashion. The two magnificent volumes, rich in perspective and thorough in analysis, are therefore without any doubt among the most authoritative works on the crime of aggression.'

Larissa van den Herik Source: Leiden Journal of International Law

'Kress and Barriga have compiled an impressive and richly nuanced collection of scholarship on the crime of aggression, comprising historical, theoretical, conceptual, technical, practice-oriented and philosophical perspectives, which convey the complexity of the legal issues that arise from the crime of aggression as defined in Kampala. In light of the recent activation of the jurisdiction of the ICC [International Criminal Court] over the crime of aggression in July 2018, this extensive commentary will appeal to scholars and practitioners as a contemporary source of reference.'

Meagan S. Wong Source: Journal of Conflict & Security Law

'These volumes could be regarded as an immense contribution in the area of international criminal law providing an overview of the state of play regarding the crime of aggression. All the fifty-three contributions extensively deal with both substantive and procedural issues. The detailed bibliography in each of the chapters provides an advantage to those who intend to research further.'

V. G. Hegde Source: Indian Journal of International Law

‘… the book edited by Claus Kreß and Stefan Barriga offers an engaging narrative which explores every aspect of the crime of aggression, as it discusses not only theory and history, but also as many practical aspects as possible. It will certainly find a well-deserved place on the [shelves] of many practitioners and academics.’

Agata Kleczkowska Source: Polish Yearbook of International Law

‘The Crime of Aggression: A Commentary is nothing short of a jewel. The editors have succeeded in compiling in two majestic tomes all the material indispensable for grasping in depth the milestone achieved in Kampala. From the attempted trial of the Kaiser, via Nuremberg to Kampala - and now New York - the crime of aggression has always attracted and continues to attract a significant degree of controversy … Whether one looks for an historical, legal-technical, theoretical, critical, political or philosophical account of the crime of aggression, this commentary will illuminate his or her research. Indeed, it delves profoundly into all aspects of the crime and is therefore an essential read for international criminal law scholars, policymakers and practitioners.’

Alexandre Skander Galand Source: European Journal of International Law