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, Eric Jensen, Adil Ahmad Haque, and more to come.

I appreciate the opportunity to share my observations about the newly published Defense Department Law of War Manual. I believe the authors of the manual, and all who contributed to its development and publication, deserve much praise. It is common knowledge that this was a complex process that spanned many years. While I have no doubt that there will be criticisms of the manual’s content, I don’t think that anyone can credibly criticize the overall effort to produce this important document.

Additionally, I think it is important to remember why this manual was published: to provide greater guidance and clarity for the members of the US Armed Forces. It is, ultimately, a statement of doctrine to facilitate the planning and execution of military operations in accordance with the law. While the density of the manual — including the laudable effort to provide support for many of the assertions in the style of an academic treatise — may give the end product the flavor of a scholarly work, it is anything but. For commanders and the lawyers who advise them, decisive action is the essence of their mandate: decisions are framed by law and policy, but are ultimately focused on mission accomplishment. Providing greater clarity to facilitate the military decision-making process was, of course, not an easy task. While well reasoned criticisms will ideally contribute to improvements in the manual going forward, it is useful to bear in mind these dynamics as a component of any critique of the final product.

To that end, I would like to highlight one opportunity I believe the manual failed to fully exploit: recognizing that the LOAC obligation to take all feasible precautions to mitigate the risk to civilians and their property resulting from military operations is broader than a mere rule, but is instead a fundamental principle of the law of armed conflict. 

Perhaps unsurprisingly, the manual emphasizes the obligation to consider feasible precautions during target selection and engagement, essentially echoing the obligation established by Article 57 of the 1977 Additional Protocol I to the Geneva Conventions of 1949 (the primary source of treaty based regulation of the targeting process). Paragraph 5.11 of the manual provides that “[c]ombatants must take feasible precautions in conducting attacks to reduce the risk of harm to civilians and other protected persons and objects.” This is undoubtedly an important confirmation of DOD’s commitment to comply with the precautions rule of Additional Protocol I. However, it is both unfortunate and somewhat perplexing why the manual did not include precautions as one of the recognized LOAC principles; perplexing because the manual actually acknowledges a broader effect of the obligation in Paragraph 5.14, which provides, “Outside the context of conducting attacks (such as when conducting defense planning or other military operations), parties to a conflict should also take feasible precautions to reduce the risk of harm to protected persons and objects from the effects of enemy attacks.”

I think this limited stature of a precautions obligation is unfortunate for a number of reasons. First, the role of precautionary measures in the targeting process is too important to relegate to the stature of “rule,” and is more appropriately categorized as a principle. The manual’s discussion of the function of “principles” — which laudably emphasizes how they serve as a “general guide” for the conduct of war, how they “aid interpreting and applying the law of war,” and how they “work as interdependent and reinforcing parts of a coherent system” — justifies this conclusion because like necessity, distinction, and proportionality, precautions should animate the entire operational planning and execution process. Commanders should develop an instinctual commitment to constantly consider how civilian risk can be mitigated without compromising operational effectiveness. While I agree with my friend Prof. Sean Watts that the articulation of the principles actually included within this category may, in some ways, produce this effect, this does not justify omitting precautions from the list.

Second, a requirement to take “constant care” to mitigate the risk to civilians and civilian property must animate all strategic, operational, and tactical decision-making. The need to emphasize this obligation is particularly acute in an era of almost inevitable urban warfare against enemies who not only fail to respect their basic distinction obligation, but actually seek to exploit their opponents commitment to the law to gain tactical and strategic advantage. It is precisely because our armed forces must anticipate this type of battle-space that the focus on measures that reduce risk to civilians must be elevated to an overarching principle. For same reason, commanders and all military personnel must develop an instinctual commitment to implementing such measures.

Third, merely incorporating Article 57 into the targeting section of the manual as opposed to elevating the status of the precautions obligation to a principle is unnecessarily limiting. As I have proposed in a recently published article, a more expansive conception of the precautions obligation may substantially increase civilian risk mitigation in armed conflict. Treating precautions as a fundamental principle will facilitate this expansion and encourage commanders to expand their own conceptions of precautions to include aspect of risk mitigation that extend beyond measures normally associated with Article 57, to include the entire process of training, professional development, planning processes, integration of legal advisers, development of military legal expertise, and accountability efforts.

Fourth, I believe omitting precautions from the category of fundamental principles distorts the actual processes used by our very best combat leaders. While emphasis on the proportionality principle seems to be a common focal point in the critique of military operations, good commanders understand that the best practice is to avoid the need to engage in a proportionality assessment by implementing precautionary measures prior to that final step in target legality analysis. And, unlike proportionality, consideration and implementation of precautionary measures fits more naturally within the instinctual operational decision-making process. Indeed, in many situations these measures are far more objective in nature than the highly amorphous concept of proportionality; what weapon to select, angle of attack, alternative tactics, timing of attack, and even warnings and evacuations, are all concrete measures a commander can assess in terms of cost and payoff. Our doctrine should place greater emphasis on consideration of these measures precisely because when effectively implemented they may substantially mitigate the dilemma inherent in the proportionality assessment.

Fifth, I believe treating precautions as a fundamental principle more accurately reflects even the true nature of the Article 57 precautions rule. The manual’s discussion of precautions provides that commanders must take “all feasible precautions,” the common articulation of the rule. In fact, Article 57 imposes an obligation to take precautions unless doing so is not feasible. Specifically, Article 57 provides, “With respect to attacks, the following precautions shall be taken” (emphasis added). This is a subtle but important contrast. Article 57 appears to establish a presumption that precautionary measures will be implemented, qualified by a feasibility limitation. The manual’s articulation subtly inverts the nature of the controlling presumption, suggesting that feasibility is the primary consideration. It may be that in practice how the obligation is characterized has no meaningful impact on its implementation. However, elevating the obligation to the status of a principle would seem to better align with even Article 57’s presumptive obligation, for it would emphasize the constant obligation to utilize precautions to mitigate civilian risk, even if qualified in many situations by considerations of feasibility.

Finally, precautionary measures, or what I believe is better understood as a precautions principle, provide what may be the greatest hope for mitigating civilian risk for professional armed forces determined to comply with the complementary principles of distinction and proportionality. This will be true in any conflict. However, when confronting enemies who actually seek to endanger the civilian population to gain tactical and strategic advantage, such measures take on even greater significance. US commanders should develop an instinct to constantly seek to offset these illicit tactics by implementing precautions aimed at nullifying their intended effects, measures that span the spectrum from training and professional development, to targeting processes, to the measures normally associated with Article 57. These efforts will almost never be completely effective in eliminating civilian risk, and will unfortunately rarely eliminate the proportionality equation. But they may very will reduce that risk and provide greater clarity in the ultimate proportionality assessment.

Perhaps more importantly, constant consideration and implementation of precautionary measures reinforces moral clarity for the warfighter thrust into these terribly complex tactical and operational environments. The precautions principle provides a reminder to commanders and their subordinates that they constantly act to advance the law’s fundamental purpose: an effective and rational balance between the need to employ deadly combat power and the obligation to mitigate the risk to civilians produced by that employment. Thus, a precautions “principle,” perhaps more than any other principle, reflects the central balance of the LOAC itself. It is therefore should be elevated in stature to stand alongside the other fundamental principles of this vital branch of international law.