Bill Boothby on his new book “AI Warfare and the Law”
Today’s post is by my friend of many years, retired RAF Air Commodore Bill Boothby who graciously agreed to discuss his new book, AI Warfare and the Law which has just been published by the Stockton Center of the U.S. Naval War College.
Virtually all military experts agree that artificial intelligence (AI) will play an increasingly central role in warfare; indeed, many say it is changing the character of war. This inevitably raises complex questions of international law. In an Economist article last June (“AI will transform the character of war“) it was observed:
Bill’s book is designed to address some of these very thorny questions, and he brings to the task his typical expertise, thoroughness, and objectivity. What is especially helpful is that the Stockton Center is making the book available online for free.
What Bill shares so generously below is how he decided to write the book and what he wanted to accomplish. Notably, he “welcomes comments, corrections, proposed additions and deletions from the text (to be submitted through USNWC) and recognizes that as technology in this field continues rapidly to evolve, revisions of the text of the book will be required to keep it up to date.”
Here’s some late-breaking news: Bill’s agreed to join us at the LENS Conference!
Writing about AI Warfare and the Law
Bill Boothby
Between 17 and 18 years ago the author was a member of an International Group of Experts (IGE) involved in a project to produce what in due course became the Harvard HPCR Manual on the International Law Applicable to Air and Missile Warfare. The author’s main task was to produce a paper on the law applying, inter alia, to weather aircraft, unmanned aerial vehicles and unmanned combat aerial vehicles.
While writing the paper, it became clear to the author that autonomous operation of platforms of the latter two kinds was the focus of ongoing research so this aspect was included in the paper.
When presenting the paper in plenary to the IGE, the author’s remarks were received with what can best be described as a modicum of bemusement. It is a measure of how thinking has developed in the intervening years that this topic is now the subject of research in so many academic institutions, and of ongoing diplomatic discussions at the UN in Geneva.
Fast forward to late 2023 when the author was asked to review an excellent doctoral thesis produced by Jonathan Kwik, since published here. It was while reading the thesis that the author concluded that an additional book is now needed.
The purposes of the additional text would be to take the discussion of AI in warfare beyond the somewhat generalised treatment that had been seen in earlier years (of which the author’s own paper 17 years previously was a prime example).
Capabilities AI systems need to exhibit
What is now needed, in the author’s view, is a study that seeks to examine in a reasonably comprehensive and detailed way the capabilities that AI systems need to exhibit if they are to be acceptable for use in the military context.
This would involve examining the principles and rules of weapons law and of targeting law and then breaking each principle and rule down into the capabilities that an AI system will need to have in order to be capable of use in compliance with that specific provision. This was one of the important tasks of the book.
Addressing the issue of responsibility
A second task of the book was to try to get to the bottom of an issue that has bedevilled discussion of AI, and more particularly, of autonomy in the military context, namely responsibility.
Too often, for example in presentations on these matters during conferences, speakers simply failed to address responsibility issues.
When questions from the audience asked where responsibility lies, again too frequently the answer simply asserted that the commander is always responsible or something along similar lines. This approach seems to the author to over-simplify matters, so a second and equally important purpose of the book was to tackle the responsibility question head-on.
However, responsibility in the legal sphere pre-supposes legal rules that place specific obligations on identifiable individuals or other legal persons. Accordingly, in one of the later Chapters, some key legal provisions that apply to those who precede commanders in the weapon system supply chain are set forth.
This involved considering the law applicable to software designers, to weapon system manufacturers, to weapon procurers, to weapon testers, to legal reviewers of weapons, to Ministry of Defense officials concerned with introducing weapons into service and to commanders and operators of such systems. In the concluding substantive Chapter, the duties of each of those categories of individual are then teased out.
The key questions
In Chapter 1 the author set himself the task of giving sensible answers to the following questions:
1 What is AI and what are the capabilities it will enable?
2 Do AI-related capabilities have implications under the law on the resort to the use of force?
3 What are the rules of weapons law that AI weapon systems and methods of warfare must comply with?
4 What are the issues raised by targeting law that the use of AI weapons and methods of warfare must address?
5 Do international criminal law, the law of neutrality and the law relating to non-international armed conflict include provisions of relevance to the use of AI weapons and methods of warfare?
6 What positions are States adopting in their discussion of autonomous weapon systems?
7 What bodies of law outside the law of armed conflict are of potential relevance to the employment of these AI capabilities?
8 Is it sufficient to say ‘the commander is always responsible’ or does responsibility in the AI context go wider?
In a sequence of Chapters the book seeks to address each of these questions in a logical way and the conclusions that the author draws from his analysis are summarised in the concluding Chapter of the book.
Concluding observations
A final point should be made and emphasised. The author makes no claim to having identified all of the capabilities that AI systems must have to be acceptable for military use. This process of operationalising the military employment of AI must of necessity be iterative.
The author therefore welcomes comments, corrections, proposed additions and deletions from the text (to be submitted through USNWC) and recognises that as technology in this field continues rapidly to evolve, revisions of the text of the book will be required to keep it up to date.
The book, AI Warfare and the Law, was published on 14 January 2025 by the United States Naval War College in International Law Studies and is available on a free access basis here. The author wishes to place on record his gratitude to the USNWC for its willingness to publish this work and for the efficiency of the pre-publication process.
About the Author:
Air Commodore Bill Boothby retired as Deputy Director of Royal Air Force Legal Services in July 2011. He took a Doctorate at the Europa Universität Viadrina, Frankfurt (Oder) in Germany and has published books, inter alia, on Weapons Law, Targeting Law, the law relating to conflict and on new and emerging technologies.
More recently with Prof Wolff Heintschel von Heinegg, he published a Commentary on the US DoD Law of War Manual and ‘Nuclear Weapons Law’, both with CUP. His book on AI Warfare and the Law was published by USNWC in January 2024 and a revised book on Nuclear Weapons Law will be published in May 2025.
He has been a member of Groups of Experts that addressed Direct Participation in Hostilities and that produced the HPCR Manual of the Law of Air and Missile Warfare, the 2013 Tallinn Manual on the Law of Cyber Warfare and the Leuven Manual on Peace Operations Law. He is Visiting Professor at the University of Johannesburg and an Associate Fellow at the Geneva Centre for Security Policy.
The views expressed by guest authors do not necessarily reflect my views or those of the Center on Law, Ethics and National Security, or Duke University. See also here.
Remember what we like to say on Lawfire®: gather the facts, examine the law, evaluate the arguments – and then decide for yourself!
