Editor’s Note: Just Security is holding a “mini forum” on the new Defense Department Law of War Manual. This series includes posts from Sean Watts and others.

After reviewing the Pentagon’s new Law of War Manual, I was struck by its purpose and how well it serves that cause. Paragraph 1.1.1 states: “The purpose of this manual is to provide information on the law of war to DOD personnel responsible for implementing the law of war and executing military operations.” Having officially said that in the very first textual paragraph of the manual, the writers had to be aware this manual would also be looked to far beyond the US military, including by other nations who are formulating their own law of war (LOW) policies, allies who are considering US policy for purposes of interoperability during combined military operations, transnational and international organizations such as the International Committee of the Red Cross (ICRC) who look to such manuals when considering the development of customary practice, and even national and international tribunals who adjudicate LOW questions with respect to the criminality of individual actions.

With that in mind, it seems easy to say that the current manual is a significant departure from its many predecessors and sources as outlined in the Preface. For example, one of the manual’s immediate predecessors, Army Field Manual: The Law of Land Warfare from 1956, contained hardly any footnotes, was 163 pages long, and stated its purpose as being to “provide authoritative guidance to military personnel on the customary and treaty law applicable to the conduct of warfare on land and to relationships between belligerents and neutral States.” There is obviously a significant difference in providing “information” and “authoritative guidance.” This difference is reiterated in the new manual’s paragraph on scope which states that the work “is not a definitive explanation of all law of war issues. … This manual is not a substitute for the careful practice of law.”

Given this, I think we have to ask ourselves why DOD is taking this different approach and whether the different approach was the right approach. One of the great benefits of the earlier manuals that preceded this new manual was their accessibility. The format of the 1956 manual, for example, included reproducing existing treaty law in bold print under applicable headings and then adding commentary in normal print to describe custom or national practice in a particular area. Its size made it easy to put in one of the side pockets of the current military uniform. The new manual will not be nearly as ready a reference; it certainly won’t fit in anyone’s uniform pocket and probably not even a backpack if any other items also have to be there. On the other hand, the electronic nature of military law practice in modern armed conflict makes delivering advice to commanders difficult without access to electronic media, perhaps now including the Law of War Manual.

Another potential reason for this different approach with the new manual is the inevitable use of it in the determination of customary practice. In response to the ICRC’s Customary International Humanitarian Law Study, then-State Department Legal Advisor Bellinger and then-Defense Department General Counsel Haynes chastised the ICRC for using DOD publications as statements of US practice and opinio juris when those publications were not meant to announce the official DOD policy. The manual goes to great lengths to preclude similar use:

This manual does not, however, preclude the Department from subsequently changing its interpretation of the law. Although the preparation of this manual has benefited from the participation of lawyers from the Department of State and the Department of Justice, this manual does not necessarily reflect the views of any other department or agency of the U.S. Government or the views of the U.S. Government as a whole.

The discussion on sources and their use reiterates this point. The writers of the manual wanted to be very clear that they did not anticipate they were writing into law the US position on the law of war.

Finally, this manual is clearly not a manual for non-lawyers. Another of the sources for the new manual is The Commander’s Handbook on the Law of Naval Operations. This handbook, last edited in 2007, is the naval counterpart to the Law of Land Warfare. It was written for commanders and not lawyers. In fact, in 1997, a separate annotated version of the handbook was produced to provide further detailed guidance to lawyers. The manual does not appear to carry on the tradition of being written for commanders. Even just a quick stroll through the pages makes it clear that this is a lawyer’s reference, not a commander’s, and certainly not a digestible source for the individual soldier, sailor, airmen, or marine. On the other hand, the increasing complexity of military operations may have required such an approach. Any commander today who would make a decision on the treatment of detainees, the targeting of civilians who might be directly participating in hostilities, or the classification of persons on the battlefield without at least seeking the input of his lawyer, if available, would be accepting at least a little risk.

Only time will truly determine the utility of this new manual. The Army is set to release its own new manual, Army Field Manual 6-27 (a replacement for the Law of Land Warfare). It will be much shorter and less like a treatise or law review article. Perhaps the combination of the two will provide exactly the right mix of law of war guidance for judge advocates who are providing on-the-spot legal advice to military commanders who face a multi-faceted set of legal issues on today’s complex modern battlefield.