Chapter 6 examines whether the weapons review obligation as formulated under Article 36 could have now attained customary international law status with the consequence that even States not party to Additional Protocol I are equally required to review weapons for their compliance with applicable international law. This issue remains contentious in the legal literature, with some commentators supporting the customary nature of Article 36 and others being less certain of this obligation. The chapter argues that, in the absence of ‘extensive and virtually uniform’ State practice showing that new weapons, means and methods of warfare are reviewed at the earliest stage in the acquisition process as a matter of law, no customary rule mirroring Article 36 exists. The chapter also demonstrates that, contrary to the argument advanced in the expert literature, an obligation narrower in scope – requiring States to review weapons ‘before fielding’ – also cannot be ascertained. Such an argument is simply not persuasive given the lack of required State practice and opinio juris. [164 words]

Relying on the methodology explained in the preceding chapter, Chapter 4 examines the object of the review procedure – ‘a new weapon, means and methods of warfare’. It argues that the object of the review has a broad meaning and covers a wide range of existing and emerging military technology designed or, in certain circumstances, used to trigger damage to objects or injury to individuals. ‘Methods of warfare’ relate to the ways weapons are used as well as operational tactics, techniques and procedures resorted to on a structural basis. The provision covers military capabilities newly introduced into the State’s arsenal, state-of-the-art weapons technology, and existing weapon systems that are adapted in a way that alters their use or effects. [118 words]

Chapter 8 looks at an Article 36 review of autonomous weapons systems. Having first addressed the progress of debates about potential future regulation of such systems at the international level, it delineates the notions of autonomy, artificial intelligence and learning systems. The chapter shows that military capabilities underpinned by machine learning and deep learning technologies require a new understanding of how provisions of targeting law can be meaningfully translated to the context of autonomous systems and examined in the framework of Article 36. It also demonstrates that determining the novel character of learning autonomous capabilities to ensure timely provision of legal advice, gaining assurance of complex adaptive systems’ performance accuracy and reliability, or identifying a set of requisite control measures, are all issues that ‘traditional’ weapons reviews do not have to grapple with at all, or at least not to the same extent. [143 words]

The introductory chapter establishes the context of the discussion and introduces the reader to the requirement placed on States by Article 36 to review the legality of a new weapon, means or method of warfare. With significant funding flowing worldwide into the development of autonomous weapons systems and cyber capabilities, including capabilities underpinned by Artificial Intelligence, the chapter further explains the focus of this book on both types of technology. Being software driven, autonomous weapons systems and cyber capabilities pose a similar set of challenges for ‘traditional’ Article 36 review mechanisms, offering a valuable case study to examine where such mechanisms may need to be adapted in light of contemporary circumstances. The chapter concludes by illuminating doctrinal and empirical sources on which the analysis in the book is based. [129 words]

Chapter 9 focuses on an Article 36 review of (autonomous) cyber capabilities. As in the case of autonomous weapons systems, the most burning questions for a weapons review in the cyber context remain: How to meaningfully incorporate advice on the law of targeting as part of the weapons review? How to determine when a given capability is ‘new’ for review purposes and when to initiate a review? How and when can testing and evaluation processes meaningfully inform the review outcome? Furthermore, some challenges distinct to cyber capabilities also exist. Most importantly, cyber capabilities test the underlying assumptions of the law of armed conflict. The effects of their use may be more deleterious than the consequences produced by traditional weaponry, and yet they may fall outside the legal review requirement because the effects produced do not constitute an ‘attack’ in its conventional interpretation. [142 words]

Chapter 7 examines the obligation of States under Article 82 of Additional Protocol I to provide for legal advisers to military commanders. It tests the argument that providing such advisers is sufficient to ensure that new weapons will be reviewed as a matter of law. It concludes that, while in certain scenarios an Article 82 adviser can perform an ad hoc weapons review, a State generally cannot avail itself of an argument that providing for legal advisers under Article 82 is also sufficient to meet the requirements of Article 36. This is so because compliance with the latter requires adopting a certain internal approach or coherent national measures whenever a State develops or purchases a new weapon. Above all, the acquisition agencies involved in the procurement process should be aware of the Article 36 legal review requirement. Therefore, and unless a State can produce evidence of a functioning review process, it cannot be presumed that compliance with Article 82 equally implies due respect for the State’s obligations under Article 36. [170 words]

Relying on the methodology explained in Chapter 3, Chapter 5 clarifies the duty bearer of the weapons review obligation — ‘a High Contracting Party’ — and considers the process and standard of review covered by the terms ‘study, development, acquisition or adoption’, ‘to determine’, ‘in some or all circumstances’ and ‘this Protocol or … any other rule of international law’. It concludes that the Article 36 obligation rests on each State Party to Additional Protocol I and allows for variations in terms of form and procedure. While the establishment of a standing or permanent mechanism is not required as a matter of law, States regularly developing or purchasing weapons must adopt a certain internal approach or coherent national measures to examine the legality of new weapons. The legal standard of review indisputably comprises treaty and customary law of armed conflict. However, the proposition advanced in the legal literature to extend the review scope to human rights is unlikely to enhance protection already offered under the law of armed conflict and thus justify the inclusion of such rights in the Article 36 analysis. [181 words]