2023 DoD Manual Revision – Handling Uncertainty in the Law of Attack

(Editor’s note: This post is part of a series analyzing the 2023 revisions to the U.S. Department of Defense’s Law of War Manual.)

A Civilian Status Presumption

The recent revisions to the DoD Law of War Manual have sparked some concern with regard to its adoption of a presumption of civilian status when conducting attacks. It is a topic that I addressed with Oona Hathaway and Marty Lederman in a 2016 Just Security post. We were concerned about text in the 2015 Manual that read, “[u]nder customary international law, no legal presumption of civilian status exists for persons or objects, nor is there any rule inhibiting commanders or other military personnel from acting based on the information available to him or her in doubtful cases” (§ 5.5.3.2).

Suggesting that the text be revised in a 2016 Manual update, we argued that “the claim that there is no legal presumption of civilian status is clearly mistaken.” Thus, while acknowledging that it “might be difficult to articulate precisely how much doubt is too much doubt to permit the use of force,” we urged that the 2016 revisions, at a minimum, recognize that there is a “legal presumption of civilian status when the commanding officer has little or no reason to think that a person is part of enemy forces (or a civilian directly participating in hostilities), where the preponderance of evidence points to civilian status, or where the officer is not fairly confident that the person is a lawful target.” In our estimation, the suggested clarification was consistent with U.S. practice on the battlefield and reflected the minimum requirements of the law of armed conflict. Ryan Goodman followed in 2022 with a Just Security piece that comprehensively cataloged evidence of such a presumption in law and practice.

Although they fell on deaf ears in 2016, such concerns bore fruit in the DoD Law of War Manual update released this week. Lest there be any doubt, DoD General Counsel Caroline Krass confirmed in the post that opened this Articles of War forum that there is “a legal duty to presume that persons or objects are protected from being targeted for attack unless the available information indicates that they are military objectives” (emphasis added). Section 5.4.3.2 of the revised Manual explains,

Under the principle of distinction, commanders and other decision-makers must presume that persons or objects are protected from being made the object of attack unless the information available at the time indicates that the persons or objects are military objectives. This presumption is the starting point for the commander or other decision-maker’s good faith exercise of military judgment based on information available at the time. For example, if there is no information indicating that a person is a combatant or a non-combatant member of the armed forces, then commanders or other decision-makers must presume that person is a civilian. Under such a presumption, the person may not be made the object of attack unless the available information evaluated in good faith indicates that the person takes a direct part in hostilities. Similarly, an object dedicated to civilian purposes (such as a place of worship, a house or other dwelling, or a civilian school) is a civilian object and may not be made the object of attack, unless the available information evaluated in good faith indicates it is a military objective in the circumstances (emphases added).

This U.S. interpretation of customary IHL is consistent with the two 1977 Additional Protocol I doubt provisions that bind 174 States (but not the United States), including most of our closest allies and partners. Article 50(1) provides,“[i]n case of doubt whether a person is a civilian, that person shall be considered to be a civilian,” while Article 52(3) of AP I notes that “[i]n case of doubt whether an object which is normally dedicated to civilian purposes, such as a place of worship, a house or other dwelling or a school, is being used to make an effective contribution to military actions, it shall be presumed not to be so used.”

As to Article 50(1), the Manual notes that “DoD has previously expressed concerns with interpretations of Article 50(1) that would depart from customary international law.” I have long agreed with this very surgically crafted text. In my mind, the issue is not whether the provision reflects customary law. It does, a position taken by, for instance, the International Criminal Tribunal for the former Yugoslavia (ICTY) in its 2004 Blaškić Appeals Chamber judgment (¶¶ 110-111). Instead, the problem is that there are interpretations of it that do not, especially unrealistic claims that doubt as such precludes attack. That was never the intent of the provision, as is clear from its travaux (see discussion here at 156-158).

With respect to Article 52(3), identical text appears in the 1996 CCW Amended Mines Protocol, Article 3(8)(a), to which the United States became a Party in 1999. The Protocol’s 1997 Letter of Submittal to the Senate noted that the obligation was “already a feature of customary international law applicable to all weapons” (see Encl. A). The Manual acknowledges that the United States has long recognized the provision as reflecting customary law (§ 5.4.3.4.).

For me, the central operational question is not whether there is a legal presumption of civilian status. In practice and in law, such a presumption, or more accurately, an obligation to identify the target as a military objective (a term I use here to include targetable individuals), exists. Instead, the real challenge for forces conducting attacks is determining when uncertainty as to the status of the target precludes attack by rendering it unlawfully “indiscriminate”?

The Central Question

Concerning that question, the 2023 revised DoD Law of War Manual points out that

The law of war accounts for the limited and unreliable nature of information in armed conflict. Individuals may consider persons or objects to be military objectives and make them the object of attack even if they have some doubt, provided that commanders and other decision-makers make their decisions in good faith based on the information available at the time, take feasible precautions to verify that the person or object is a military objective, and act consistent with other obligations to seek to reduce the risk of incidental harm to civilians and other persons and objects protected from being made the object of attack, as explained in this subsection.

General Counsel Krass noted that this approach “affirms that the law of war does not prevent commanders and other personnel from making timely decisions and acting at the speed of relevance, including in high-intensity conflicts, based on their good faith assessments of the information available at the time.” In my opinion, this is a sensible approach to uncertainty that emphasizes that the mere existence of some doubt is not always an obstacle to attack. As Lieutenant Colonel Mike Schauss and I observed in a 2019 Harvard National Security Journal article: “Targets sometimes may be attacked despite the existence of some doubt. To hold otherwise would fly in the face of state practice stretching back to the crystallization of the principle of distinction” (at 156). The Manual usefully informs U.S. forces how to make the military objective assessment—by acting in good faith, considering available information, and taking feasible precautions to verify the target and minimize civilian harm.

Michael Meier, the U.S. Army’s Special Assistant to the TJAG for Law of War Matters, pointed out in his contribution to this forum, that this approach, which dispenses with the earlier rejection of a presumption of civilian status, “more accurately reflects U.S. practice concerning the treatment of civilians and civilian objects.” Indeed, the 2019 Army/Marine Corps manual, The Commander’s Handbook on the Law of Land Warfare, while hesitating to label its 2016 DoD counterpart wrong on the presumption issue, nevertheless stated that “as a matter of practice due to operational and policy reasons, … Soldiers and Marines should consider that person or object as a civilian or civilian object” when doubt as to military objective status exists (¶ 2-54).

Of course, pressing ahead in the face of uncertainty must be reasonable to be lawful. As an ICTY Trial Chamber observed in its 2003 Galić judgment, “a person shall not be made the object of attack when it is not reasonable to believe, in the circumstances of the person contemplating the attack, including the information available to the latter, that the potential target is a combatant” (¶ 50). Similarly, the Harvard Manual on International Law Applicable to Air and Missile Warfare (AMW Manual) provides that the “degree of doubt necessary to preclude an attack is that which would cause a reasonable attacker in the same or similar circumstances to abstain from ordering or executing an attack” (at 90-91). The DoD Law of War Manual (§ 5.4.3.2) is in full accord: “The law of war requires commanders and other decision-makers to exercise professional judgment in making any assessment that a person or object is a military objective, and what is reasonable in making that assessment depends on the circumstances” (emphasis added).

But when is proceeding in the face of uncertainty unreasonable and, therefore, unlawful? That is the central question.

Uncertainty

The practical challenge for armed forces in the field lies in answering this question. For instance, when can one say that a potential target in civilian attire is a member of the adversary’s armed forces or an organized armed group it is fighting? When is it lawful to conclude that a person seen near a roadway with digging implements is on his way to bury a roadside improvised explosive device (and thus qualifies as a direct participant in hostilities) rather than a farmer or construction worker headed to work? What information is necessary in the attendant circumstances to lawfully conclude that a civilian building is being used, or will be used, for military purposes and is, therefore, a military objective? The reality is that combat operations are often brimming with uncertainty.

The determination of whether such uncertainty precludes attack is sometimes understood by reference to a unidimensional threshold lying at a particular point along a continuum of certainty as to the target’s identity. By this (in my view) oversimplification of the indiscriminate attack rule, the attacker need only be certain enough (wherever that threshold lies) that the target is what the attacker believes it to be to satisfy the requirement of target verification. This is understandable in light of target verification requirements articulated in such terms as “positive identification,” “reasonable certainty” (Iraq ROE card), “substantial doubt” (UK Law of Armed Conflict Manual ¶ 5.3.4), and “near certainty” (U.S. counterterrorism strikes).

But as LTC Schauss and I pointed out, uncertainty is seldom dealt with on the battlefield as a static, quantifiable threshold that must be crossed before attacking, nor does such an approach “adequately operationalize the balance between humanitarian considerations and military necessity that all ‘conduct of hostilities’ rules must reflect” (at 149). In practice, uncertainty is addressed in a much more nuanced manner, one that “involves a multifaceted situational assessment when planning, approving or executing attacks” (id.). The question is not whether a one-size fits all threshold has been reached, but instead, whether the attacker is confident enough in the circumstances to mount the attack lawfully. At a certain point, the attendant circumstances are such that humanitarian concerns about mistakenly striking civilians or civilian objects give way to the need of the attacker to kill, destroy, or otherwise neutralize what may be a military objective.

There is a broad consensus among international humanitarian law (IHL) experts and entities that the certainty requirement should be understood contextually. For instance, the ICRC’s Interpretive Guidance on the Notion of Direct Participation in Hostilities notes, “Obviously, the standard of doubt applicable to targeting decision … must reflect the level of certainty that can reasonably be achieved in the circumstances. In practice, this determination will have to take into account, inter alia, the intelligence available to the decision maker, the urgency of the situation, and the harm likely to result to the operating forces or to persons and objects protected against direct attack from an erroneous decision” (at 76, emphasis added; see also ICRC, Customary International Humanitarian Law study, at 24). Groups of experts have taken the same approach. The AMW Manual explained, for example, that the level of doubt required for application of the civilian presumption “is that which would cause a reasonable attacker in the same or similar circumstances to abstain from ordering or executing an attack” (at 119).  And the DoD Law of War Manual (§ 5.4.3.2) emphasizes precisely this point. In discussing what it means by “good faith,” the Manual observes “what is reasonable … depends on the circumstances” (emphasis added).

This leads to the questions of which factors matter in that contextual determination and how they should be weighed during the multifaceted situational assessment. I believe the answers are to be found in the aforementioned military necessity/humanitarian considerations balancing (on the balancing dynamic generally, see here). What this means in practice is that the greater the value of a target, the more uncertainty may be countenanced in an attack, and vice versa.

It is an approach already found elsewhere in IHL, most prominently in the rule of proportionality. On the one hand, that rule allows for significant expected civilian harm if the concrete and direct military advantage anticipated to result from the attack is great enough. On the other, even a little expected civilian harm can render an attack unlawful if the anticipated military advantage is “excessive” relative to that advantage. Similarly, the feasible precautions in attack rule allows for the consideration of operational factors, including protection of the attacker’s forces, in determining whether it is “feasible” to avoid causing civilian harm. If the attacker could avoid civilian harm by using different tactics or weapons, for instance, but doing so would sacrifice anticipated military advantage, the alternative is not “feasible” as a matter of law.

In the target identification assessment, the military advantage anticipated (the desired effect) if the target is a valid military objective represents the military necessity. Misidentification of a civilian or civilian object constitutes the humanitarian consideration. The assessment aims to determine when the risk of harm to protected persons or objects due to misidentification would be acceptable because of the anticipated value of the target if it is a lawful military objective. Lest there be any confusion, I am speaking only to the issue of target verification, not proportionality or precautions.

Uncertainty plays a central role in this assessment, for the “value” attributed to the desired effect should be discounted by the degree of uncertainty regarding: (1) the reliability of target identification; (2) the probability that the attack will cause the intended destruction or death; and (3) the likelihood that the intended destruction or damage will yield the desired effect. This sounds complicated, but responsible and disciplined attackers usually perform this analysis intuitively. In our piece, LTC Schauss and I offer examples of each (at 165-166). Uncertainty can also play a role in assessing humanitarian considerations, especially during attacks on objects, like buildings. For instance, if the attacker is wrong about the military purpose of the building, the amount of civilian harm may rise significantly. The greater the risk of civilian harm as a result of misidentification, the less reasonable a determination that the object is a military objective becomes.

The point is that uncertainty affects an attacker’s understanding obligation to verify the target as a military objective in a reasonable manner. Such assessments are often highly contextual and should usually be made on a case-by-case basis. The DoD Law of War Manual (§ 5.4.3.2) acknowledges as much when it notes that in assessing the reasonableness of a determination that the target is a military objective, “[r]elevant circumstances may include the time and resources reasonably available, the risks to civilians from an erroneous decision, risks to friendly forces, and the military advantage expected from the attack.”

Concluding Thoughts

In my estimation, the revisions made to the DoD Law of War Manual are positive. They articulate an approach to targeting that I believe is consistent with customary international law and better reflects how those making military objective assessments approach targeting. In my view, there is an affirmative obligation to conclude the target is a military objective; the mere existence of some uncertainly does not preclude so concluding; the applicable standard is one of reasonableness; reasonableness is determined contextually and variably; and the relevant context includes the degree of uncertainty an attacker has about an array of factors. As complicated as this may sound, well-trained and responsible military professionals usually perform much of this analysis intuitively. The Department of Defense’s recognition of a presumption of civilian status is appropriate.

Finally, I acknowledge the insights of my colleagues who have expressed concern with styling the attacker’s obligation as involving a presumption; they are some of the best IHL thinkers in the business. Their analysis is legally sophisticated, and I acknowledge the risk that textually styling the obligation as a “presumption” risks causing U.S. forces to become overly cautious; after all, the question attackers ask themselves in practice, and correctly so, is whether they are attacking lawful targets, not whether they have “rebutted a presumption,” a particularly legalistic notion. Yet, I hope that proper training of judge advocates and operators and operational safeguards, such as rules or engagement and other guidance, will mitigate the risk of hesitation to which they perceptively point.

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Michael N. Schmitt is the G. Norman Lieber Distinguished Scholar at the United States Military Academy at West Point. He is also Professor of Public International Law at the University of Reading and Professor Emeritus and Charles H. Stockton Distinguished Scholar-in-Residence at the United States Naval War College.

Photo credit: Patrick Albright, U.S. Army