Dr. Jan Ganschow utilized Mr. Gary Solis’s The Law of Armed Conflict (Third Edition) during Allied Spirit XIII, a Large-Scale Operations Exercise with 6,300 troops in Hohenfels, Germany. (Photo courtesy of author)
Book Review
The Law of Armed Conflict
International Humanitarian Law in War (Third Edition)
Reviewed by Dr. Jan Ganschow
One requirement of being a German military Rechtsberater (legal advisor, LEGAD) or a judge advocate (JA) with the U.S. Army Judge Advocate General’s Corps remains constant: in order to effectively and efficiently advise battlefield commanders on how to achieve lawful mission accomplishment, a military legal professional must have the right skills, knowledge, and experience. This simple truth is valid for every level of command. When it comes to the most challenging fields of legal expertise, i.e., operational law with the law of armed conflict (LOAC) as its supreme discipline, the stakes are particularly high. But there is a silver bullet that, over a decade of personal experience, has steadily enabled the LEGAD or JA to get a jump-start: Gary D. Solis’s book The Law of Armed Conflict: International Humanitarian Law in War. 1
The title holds true but is too modest. The work is not only a primer on LOAC but also an outline of operational law framework rendering it the one book that I would put into my rucksack (besides a copy of the Operational Law Handbook2 with its LOAC Documentary Supplement3 ) to prevail on the legal battlefield. Of course, the LEGAD or JA also needs to know the law, national regulations, commander’s directives, and the doctrinal/political framework, etc. But without an explanatory framework and a reliable source for quick cross-checks, these sources stand apart from each other, sometimes even seemingly detached from the case at hand.
Here, The Law of Armed Conflict can be seen as a toolbox (e.g., the Rules of Engagement (ROE) are explained in their own chapter, like formulating mission-specific ROE etc.) to support required skills development with its didactical-methodological approach. Solis provides unbiased and thoroughly referenced, in-depth knowledge of de lege lata, the law that is,4 as well as de lege ferenda, the law that is to come,5 which, in the time between the first and third edition, have often proven prophetic. More than once, Solis’s own experience as a combat veteran and JA assisted me in my practice.
Since a legal practitioner is always short on time, I was happy to find Solis’s elaborations addressing the time constraints and needs of the military LEGAD or JA. The book is well-indexed, divided into topical chapters with subchapters, rendering it user-friendly for the concrete knowledge-seeker and time-pressured producers of legally-charged texts. Every chapter includes a summary of the most important facts and findings. Quite a few times, despite my years of experience the field, I consulted it for a quick reference on a specific topic, only to discover that the LOAC issue at hand was much more complex than I anticipated. Solis competently guides the reader through the maze that LOAC sometimes can be, with all its politically-, ethically-, and culturally-charged sub-layers, and does so in a manner that is interesting and engaging. I was often surprised by what I got as “knowledge bycatch” when I consulted The Law of Armed Conflict (ever heard of the “Rendulic rule”6 or the “Commander’s Seven Routes to Trial”7 ?).
Because of Solis’s credibility as a Vietnam War veteran, a former lawyer with the U.S. Marine Corps, and an acknowledged academic, and the selectively-compiled cases and materials, The Law of Armed Conflict also makes for a fascinating read. Solis empowers his readers by offering not only an understanding of the content of LOAC but also of its structure, the historical and political background. He delineates the most important tools for the operational lawyer and thereby allows the reader to put these ideas straight into practice. Accompanying me from one mission area to another since the first edition, The Law of Armed Conflict proved its value many times—and continues to do so with this third edition.8
Personally, I very much enjoy Solis’s explanations on the historical and political backgrounds of relevant LOAC structures and norms.9 Solis’s elaborations are captivating to read and show what a monumental achievement it has been to develop this body of law through the ages in bloody fits and starts. They also help to put today’s LOAC into a societal context. Only with these backgrounds can one fully comprehend the stage of development and interconnectedness of the different legal instruments and norms of this legal field, enabling sound, holistic legal advice.
Solis leads the readers through LOAC’s rich complexity, which, as he shows, partly stems from its history,10 how it was created and applied through the ages, its purposes, and effects. And while we tend to think that the operational surrounding of the military LEGAD or JA becomes extraordinarily complex given the doctrinal shift from counterinsurgency to artificial intelligence-, drones-, and cyber-driven Joint All-Domain Warfare, the historical explanations in The Law of Armed Conflict give the reader the sense that militaries in earlier decades probably felt likewise. And still, at least to my knowledge, the legal services of most of the NATO members’ militaries did not implement highly specialized career tracks within their personnel development system but kept to the generalist LEGAD or JA rewarding a wide range of different assignments.
So even while The Law of Armed Conflict necessarily contains a vast amount of legal-technical facts in order to illustrate LOAC exactly, it never becomes a dry read. The reader is invited on a worldwide LOAC journey that begins at the first international war crime prosecution.11 This occurred in 1474 via the beginning of the codification of modern LOAC by my personal hero, Francis Lieber,12 who fought in the Napoleonic Wars before he migrated to the United States from his native Germany. From there, it continues over the mind-boggling legal aspects of the internet as battlefield13 to hybrid warfare,14 lethal autonomous weapon systems,15 and artificial intelligence.16
Solis also gives room to the human dimension and makes a certain personal involvement by the reader possible. Solis catches more than the reader’s professional attention when he frequently cites fascinating primary sources (like a “Top Secret” CIA memo17 or a rare infantryman’s poem18 about LOAC) and accounts of LOAC application in combat, giving his subject matter a human voice. In nearly forty sidebars, Solis makes topical excursions that let the readers experience real life instances and gripping anecdotal reports to exemplify and illustrate the respective chapters. Maybe this, I think, is key to the book’s success and makes it so much more than a student’s textbook.
In a combat zone, mere juridical advice might not always be enough. Solis knows this from personal experience both as a platoon leader and company commander tasked with fighting and winning battles and as a JA tasked with enabling lawful mission achievement and upholding the law. The Law of Armed Conflict reflects this. Be it counterterrorism operations or Joint All-Domain Warfare with Large Scale Combat Operations, the use of military force is legally multilayered and complex. New technologies and artificial intelligence bring along new tactics, techniques, and procedures that add to the complexity of the battlefield. Solis finds that, since publication of the second edition in 2016,19 armed conflicts have changed substantially; combat operations are more technically oriented, more “wired,” more lethal.20
I rank this book high among my most-consulted public sources21 for my work in the field of LOAC because its author, having proven many times to possess the right skills, knowledge, and experience as a military officer and a JA himself, acts like an enabler to the LEGAD or JA. This book served as a metaphorical parachute when I needed backup. This was especially true while I was deployed to an area of active hostilities and tasked to deliver advice on LOAC in an austere work environment.
The Law of Armed Conflict does not include the specifics of the law of war at sea or law of aerial warfare. However, it helped me understand the full dimension of the law not only of land warfare but of warfare generally since the basic norms and structures usually apply in each operational domain. Two controversial and politically-sensitive operational law topics stand out to me: security detention22 and targeting.23 Here, and on some other topic areas, Solis also outlines the U.S. and other legal-political views, always explaining where to locate this in the legal framework. In preparation for various legal presentations on these topics, I turned to The Law of Armed Conflict for guidance and often found not only what I needed but also material to prepare for follow-on discussions, particularly with members of non-governmental organizations.
I remember a large LEGAD conference on LOAC that I had to convene in a mission area on very short notice. The conference was a success because my fellow international LEGADs agreed to use selected contents of my tattered copy of The Law of Armed Conflict as our agenda. Every session was built upon the content of one of the selected chapters, so every session was helpful to the audience. On another occasion, I was tasked to give an ad hoc briefing to a multinational staff (equivalent to a division) in theater about the concept of direct participation in hostilities and its specific impact on the conduct of certain operations. Without much time to prepare and no possibility to reach back to colleagues at higher command, I was relieved to find the topic in my copy of The Law of Armed Conflict. This was certainly better than having to rely solely on my own critical understanding of the known Interpretative Guidance on the Notion of Direct Participation in Hostilities from the International Committee of the Red Cross.24 Given this personal experience, I think it is no wonder that the 40th Judge Advocate General of the United States Army, Lieutenant General Charles N. Pede, recommends Solis’s book in his foreword to the third edition not only to students but to uniformed JAs as well.
When given short notice to deliver a product that explains the legal aspects of an actual situation in a mission area, I noticed the impulse in my colleagues and myself to consult legal blogs online to get a first idea of the problem. That is dangerous. I frequently found dubious legal opinions that claimed to accurately reflect the law but, in truth, followed an ideological agenda. I, therefore, agree with Michael Schmitt and Sean Watts when they deplore the fact that many scholars lack the appropriate education or experiential background but, nevertheless, claim LOAC expert status, misstating basic principles and rules with distressing frequency.25 Not so with Solis. Turn to his book first and then begin exploring and cross-checking when operational law and/or LOAC plays a role. You will probably find every relevant aspect covered, at least in a way that allows for further explorations. Solis takes care to produce reliable legal findings and to clearly mark areas of controversy.
The reader can tell Solis’s work has stood the test in his discussions and debates on LOAC with Soldiers and Marines fresh from combat in Iraq, Afghanistan, and Africa and that these discussion have honed the viewpoints in the book. This feeling of following a candid author and the already-mentioned fine writing style made Solis’s book a quick reference for legal products and an excellent guide in further developing my professional capacity in LOAC and my understanding of the U.S. perspective. That understanding is something a German or European LEGAD should strive to develop unless they want to run into the serious legal interoperability trouble that comes with not fully understanding where NATO’s most-powerful member state is heading.
Even while the text is heavily weighted towards the U.S. perspective, it is, as Solis explains, more than a statement of American positions since it incorporates lessons from British, Dutch, Israeli, and other combatant forces while also addressing positions of non-governmental organizations. Solis also includes legal opinions from Germany and other jurisdictions. This reflects the current Western military reality of ever more multinational coalitions and should be helpful to also legally synchronize the common efforts
For my part, I found it very enlightening to also learn about the U.S. practice when it comes to military justice26 in connection with LOAC. However, to put Solis’s elaborations on U.S. legal practice, policy,27 and doctrine into perspective, I recommend that any non-U.S. reader keep in mind the positions of their respective country and the legal positions of the European Court for Human Rights, should their country be a state party to the European Convention on Human Rights.28
My motivation to write this rather personal review about Solis’s The Law of Armed Conflict stems from a certain sentiment of gratefulness to an author who helped me with his work and thereby indirectly shaped the legal domain in military exercises, combat zones, and areas of active hostilities. Turning to Solis’s book always added value to my operational legal products and played no small part in finding the right solutions for legal challenges in theater.
Solis’s book has never disappointed me. To me, who, as a military LEGAD or desk officer, had to deliver timely work results on the tactical, operational, and strategic level, it is nothing short of a masterpiece. I am not aware of a similar work in the United States or in Europe. I hope that it will help other operational lawyers fulfill their tasks as it helped me. TAL
Dr. Ganschow is the action officer for multinational operations and interoperability with the Center for Law and Military Operations at the Judge Advocate General’s Legal Center and School in Charlottesville, Virginia.
Notes
1. Gary D. Solis, The Law of Armed Conflict: International Humanitarian Law in War (3d ed. 2021).
2. Nat’l Sec. L. Dep’t. The Judge Advocate Gen.’s Legal Ctr. & Sch., U.S. Army, Operational Law Handbook (2022).
3. Nat’l Sec. L. Dep’t. The Judge Advocate Gen.’s Legal Ctr. & Sch., U.S. Army, Law of Armed Conflict Documentary Supplement (2022).
4. De lege lata, Oxford Reference, https:// www.oxfordreference.com/view/10.1093/ acref/9780195369380.001.0001/acref9780195369380-e-519 (last visited Mar. 21, 2022).
5.De lege ferenda, Oxford Reference, https:// www.oxfordreference.com/view/10.1093/ acref/9780195369380.001.0001/acref9780195369380-e-518 (last visited Mar. 21, 2022).
6. Solis, supra note 1, at 222, 240–243 ff
7. Solis, supra note 1 at 324–329.
8. Whereas the first and second edition of The Law of Armed Conflict had 660 and 864 pages respectively, the completely updated and revised third edition finds the balance with 743 pages (and 2,732 meaningful footnotes (I counted!)). The third edition of The Law of Armed Conflict starts with tables of treaties and cases, followed by twenty-two chapters on LOAC. I deem it is worth it to name them here in order to illustrate this review:
1. Rules of War, Laws of War;
2. Codes, Conventions, Declarations, and Regulations;
3. Two World Wars and Their Law of Armed Conflict Results;
4. Protocols and Politics;
5. Conflict Status;
6. Individual Battlefield Status;
7. Law of Armed Conflict’s Core Principles;
8. What Is a “War Crime”?;
9. Obedience to Orders, the First Defense;
10. Command Responsibility;
11. Ruses and Perfidy;
12. Rules of Engagement;
13. Targeting Objects;
14. Targeting Combatants and Others;
15. Artificial Intelligence, Autonomous Weapons, Drones, and Targeted Killing;
16. Torture;
17. Cyber in the Law of Armed Conflict;
18. Attacks on Cultural Property;
19. The 1980 Certain Conventional Weapons Convention;
20. Gas, Biological, Chemical, and Nuclear Weapons;
21. Military Commissions;
22. Security Detention.
A bibliography and an index are at the end of the book.
9. I consider it a lucky circumstance that the U.S. Army JAG Corps’s historian and archivist, Fred Borch, is mentioned in the preface of the book, acting as a quasi-guarantor of Solis’s findings.
10. See Gary D. Solis, The Law of Armed Conflict: International Humanitarian Law in War 2–4, 34–66, 67–105 (3d ed. 2021).
11. Id. at 4, 26–28.
12. See id. at 35–41.
13. Id. at 533–535.
14. Id. at 142–152.
15. Id. at 464–497.
16. Id. at 464–497.
17. Id. at 527–531.
18. Id. at 280.
19. Gary D. Solis, The Law of Armed Conflict: International Humanitarian Law in War (2d ed. 2016).
20. Solis, supra note 1, at XXI.
21. Other sources I often consult include: The Judge Advoc. Gen.’s Legal Ctr. & Sch., Nat’l Sec. L. Dep’t, Operational Law Handbook (2022); Max Planck Encyclopedia of Public International Law (Anne Peters ed., Oxford Univ. Press 2008–2020), https://opil.ouplaw. com/home/mpil (accessible online to subscribers); The Handbook of the Law of Visiting Forces (Dieter Fleck ed., 2d ed. 2018); The Handbook of the International Law of Military Operations (Terry D. Gill & Dieter Fleck eds., 2d ed. 2016); The Handbook of International Humanitarian Law (Dieter Fleck ed., 4th ed. 2021); Leuven Manual on the International Law Applicable to Peace Operations (Terry D. Gill et al. eds., 2017); Legal Advisors Worktop Functional Area System, NATO, https://lawfas.hq.nato.int (last visited Dec. 29, 2022); Treaties and Customary Law, Internat’l Comm. of the Red Cross, https://www.icrc.org/en/war-and-law/treaties-customary-law (last visited Dec. 29, 2022).
22. Solis, supra note 1, at 672-695.
23. Solis, supra note 1, at 397-424 for targeting objects, 425-463 for targeting combatants and others.
24. Nils Melzer, Legal Adviser, Int’l Comm. of the Red Cross, Interpretive Guidance on the Notion of Direct Participation in Hostilities Under International Humanitarian Law (2009).
25. See Michael N. Schmitt & Sean Watts, State Opinio Juris and International Humanitarian Law Pluralism, 91 Int’l L. Stud. 171, 175 (2015).
26. See, e.g., Solis, supra note 1, at 79–84.
27. See, e.g., Solis, supra note 1, at 274–275, 593–594, 603–604.
28. Convention for the Protection of Human Rights and Fundamental Freedoms, Nov. 4, 1950, E.T.S. No. 5, 213 U.N.T.S. 221 (subsequently amended by Protocols 11, 14, 15, and supplemented by Protocol Nos. 1, 4, 6, 7, 12, 13, 16).