"Weapons and the Law of Armed Conflict," by William Boothby

Published by Oxford University Press, 2009

Although today there is a flood of books on the law of armed conflict and emerging technologies of weapons (such as armed UAVs, or autonomous or highly automated weapons), or specific weapons and the law (such as nuclear weapons, or chemical weapons, or landmines), there are surprisingly few book-length treatments of the law of weapons as such under LOAC/IHL. His Serenity, in his own work, has tended to rely on such sources as reports or journal articles from the ICRC, US Defense Department documents, particular scholarly articles on such topics as legal weapons review, or specific chapters on weapons law found in broader treatises on the law of war. So the appearance in 2009 of William H. Boothby’s treatise, Weapons and the Law of Armed Conflict, is particularly welcome, given the increasing importance of emerging weapons technology and considerations of international law. Given His Serenity’s interest in UAVs, autonomous weapons, chemical weapons, landmines, and so on, the book remains on his office bookshelf, close at hand.

Boothby retired in 2011 as Deputy Director of Legal Services (Air Commodore) in the Royal Air Force, following a long and distinguished career devoted in large part to LOAC issues, and over the last decade he has produced an impressive body of work including many articles, reports and, beyond Weapons and the Law of Armed Conflict, a second treatise published by OUP in 2012, The Law of Targeting. His latest book, Conflict Law: The Influence of New Weapons Technology, Human Rights, and Emerging Actors, which appeared from Springer in 2014, is not a treatise - but follows up observations at the end of Weapons and the Law of Armed Conflict on the outsize role of influential international advocacy NGOs in influencing weapons law, from the Ottawa conventional banning antipersonnel landmines to today’s emerging autonomous or highly automated weapon systems (set for separate review - Ed.)

Weapons and the Law of Armed Conflict is plainly written, deeply researched, and offers a solid doctrinal framework set against fundamental principles of the law of armed conflict, and a keen awareness of the practical requirements of military operations — particularly air platforms, which serves the book well in exploring issues raised by armed drones. The legal framework is doctrinally grounded in long-standing, broadly shared understandings among the world’s leading norm-setting militaries. It avoids the creative (let’s be honest - sometimes woefully ignorant) interpretations that some advocacy groups bring to the law of armed conflict; it engages closely, without necessarily agreeing, with the expert views of the ICRC, as well as other leading scholars writing within the recognizable framework of the laws of war; and it engages equally closely with both the official documents put out by the leading militaries as well as the writings of individual experts serving in or, like Boothby, retired from military legal services. Where the book suggests a path or a construction of the law of weapons to cover new situations or emerging technologies, Boothby is scrupulous about identifying where he believes ascertainable doctrine leaves off and his own construction begins.

The book’s organization is as straightforward as can be: Chapter 1 lays out background concepts in the law of armed conflict. Chapter 2 walks through the history of the law of weaponry, following a chronological order of the leading treaties and protocols. Chapter 3 considers the constituent elements of the law of weapons, starting with the question of sources, then turning to customary law and its elements, and next treaties. It ends with a careful assessment of the ICRC’s Customary Law Study and its relation to weapons law. Chapter 4 frames the law of weapons in relation to the law of targeting, drawing on Additional Protocol I (but considering in what aspects AP1 should be regarded as customary, even in relation to states such as the United States or Israel that have not adopted), and ending with a useful discussion of the law of reprisals today, in consideration of nuclear weapons or weapons of mass destruction, and not just conventional weapons. Chapter 5 turns to the first of the two core customary principles that might render a weapon unlawful as such - the prohibition on weapons that cause superfluous injury or unnecessary suffering; he points out, as Mike Schmitt, Jeff Thurnher, and many other experts in LOAC (rather than other areas of international law, such as human rights law) have pointed out, these criteria are confined to effects on combatants, not noncombatants. Chapter 6 addresses the customary principle that does apply with respect to civilians or noncombatants - indiscriminate weapons and the principle of distinction; he carefully walks through the long-established understanding of military lawyers as to the difference between a weapon that is indiscriminate as such, and a weapon that is indiscriminate for some uses on some battlefield environments, and hence banned for those, but not necessarily for others.

Having laid out those two fundamental customary principles, Chapter 7 considers special rules for the protection of the environment, and Chapter 8 introduces the key treaty with respect to particular conventional weapons - the Convention on Certain Conventional Weapons. After walking through a series of particular types of weapons in the next few chapters, the book turns to consider special problems, such as the “explosive remnants of war” problem (Chapter 17), weapons at sea (Chapter 16), and compliance with weapons law and the requirements of “legal weapons review” (Chapter 19). The final section of the book turns to emerging weapons technology (the book was published after armed drones became a public issue, but before the controversies today over autonomous weapons). It argues, in effect, that emerging weapons systems can be regulated through the existing framework of the law of armed conflict.

This is a comprehensive, thorough book. At $155 on Amazon currently, most readers will access it through an academic library - but HIs Serenity has found it an indispensable source book and path through the doctrinal thickets of a part of LOAC that is increasingly at the center of debate.