This chapter addresses the scope of regulation of means and methods of warfare generally and then examines the prohibition of weapons causing superfluous injury or unnecessary suffering, indiscriminate weapons, and weapons harming the environment. It then turns to the regulation of certain weapons, namely nuclear weapons, cluster munitions, UAVs and autonomous and automated weapons systems. The chapter goes on to review the regulation of certain methods of warfare, perfidy and ruses of war, pillage, espionage and improper use of protected emblems. It then discusses weapons review before addressing targeting, military objectives, proportionality in attack and precautions. The chapter closes with discussion of cyber warfare in this context.

This chapter suggests three legal strategies to leverage international humanitarian law for the protection of weaponised animals in armed conflict in the absence of a direct prohibition of animal weapons. Firstly, one could rely on international, regional organisation and domestic law during non-international armed conflict. Secondly, states can be confronted with their obligation to conduct weapons reviews (relating to international armed conflict). Thirdly, states proposing a ban or regulation on lethal autonomous weapons could be encouraged to promote or support comparable action towards weaponised animals. Even all three strategies in combination would not result in a universal prohibition against weaponising animals. The admittedly patchwork outcome(s) would only offer some measure of protection of animals where little currently exists. Additionally, each line of argument has the potential of gaining additional traction, whether as a matter of law, custom or policy, thus increasing the protection of animals.

Section G provides Rules and Commentaries on the legal requirements that means of nuclear warfare must be in compliance with. They include basic principles, specifically the prohibition of unnecessary suffering and superfluous injury, and the requirements emanating from the principle of distinction. The Section also addresses the prohibition of nuclear weapons that are expected to cause widespread, long-term and severe damage to the natural environment and of environmental modification techniques having similar effects. Special attention is given to the obligations under the TPNW and to the admissibility or prohibition of belligerent reprisals.

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 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]