Editor’s note: This article is the second in a new project at Just Security that assesses the U.S. Department of Defense’s Law of War Manual with a goal of providing constructive suggestions to address concerns about the Manual’s text.

This article considers how the U.S. Department of Defense’s Law of War Manual addresses the law of armed conflict protections afforded civilians who work at or near military objects (such as civilians who work on the assembly line of a munitions factory). The Manual risks creating a false impression that is not intended by the senior leadership who produced the Manual — a problem that could significantly undervalue the lives of civilians in targeting operations.

The problem appeared in the initial Manual, published in 2015, along the following lines:

Proportionality is a fundamental precept of the law of armed conflict. The principle holds that military commanders must refrain from attacks in which the expected loss of civilian life would be excessive in relation to the concrete and direct military advantage expected to be gained. The initial 2015 version of the Manual raised very serious concerns due to its suggestion that civilians who work on or near military targets would not be weighed in the proportionality analysis.

In 2016, much to the Defense Department’s credit, its Office of General Counsel (OGC) significantly revised the Manual’s chapter on civilian harm in response to constructive criticisms, which included a series of Just Security articles.

The solution was, however, left incomplete:

OGC’s leadership took significant action to repair the problem, but the revised text did not completely fulfill their objectives. The result is a section of the Manual that could leave many readers, including U.S. military lawyers (Judge Advocates, who are the primary intended audience for the Manual), with the mistaken impression that the 2016 version stands for the novel proposition that civilians in or near military objectives, while not completely omitted in the proportionality analysis, can be heavily discounted or counted as less than other civilians (what some have called “a ‘sliding scale’ of civilian valuation”). That was not the result the OGC wanted to achieve in its revision.

We should flag one structural (and more pervasive) problem with the Manual at the outset: The Manual creates this false impression due, in part, to the way many lawyers would ordinarily read the footnotes in interpreting the Department’s position on the law — as sources that support and further explain the legal propositions set out in the Manual’s text. As we discuss below, Department officials verbally disavowed this use of the footnotes upon issuing the revised version in 2016, but many of the Manual’s primary consumers are most likely, through no fault of their own, completely unaware of that fact.

The Manual should be revised to meet the objective of applying the standard proportionality analysis, and prevent such dangerous misconceptions of the law of armed conflict and of the Department’s position on the law. The Manual’s language should clearly communicate that all civilians who are not taking direct part in hostilities must be treated as such, including for the purposes of proportionality assessments, regardless of their location.

This essay traces the evolution of the Manual’s provisions from the highly flawed initial version in 2015 to the improved but still problematic 2016 update. This essay then suggests several approaches to provide a more complete fix.

* * *

We believe the following chronology is a helpful way to organize the discussion.

A. Chronology

June 2015: The Department of Defense publishes the first-ever department-wide manual on the law of armed conflict

In June 2015, the Department released its Law of War Manual, which the Department describes as “a guide for DoD personnel responsible for implementing the law of war and executing military operations.”

Initial version: Department of Defense Law of War Manual 2015

“Harm to certain persons who may be employed in or on military objectives would be understood not to prohibit attacks under the proportionality rule. These categories include … civilians [sic] workers who place themselves in or on a military objective, knowing that it is susceptible to attack, such as workers in munitions factories. These persons are deemed to have assumed the risk of incidental harm from military operations.”

June 2016: Leading legal experts criticize section

About a year later, legal experts published criticisms of then-Section of the Manual (Lederman 2016 and Hathaway 2016). This Section appeared to stand for the proposition that civilians working in or on military objectives (such as a munitions factory worker) assume the risks of incidental harm from attack and therefore do not need to be considered or counted in the proportionality analysis (Hathaway 2016). As Marty Lederman wrote:

The Manual’s “assumption of risk” proposition as to the requirement of proportionality is indefensible, and threatens to unravel the proportionality rule through the back door. If an “assumption of risk” were sufficient to disqualify a civilian from consideration in a proportionality analysis, that would render the proportionality requirement virtually meaningless or inapposite, especially in light of the United States’s expansive notion of permissible military objective in noninternational conflicts.

In a final report, international experts at a meeting organized by the ICRC in June 2016 — including participants from several State and multilateral armed forces — “expressed disagreement with the position taken in the 2015 US Department of Defense Law of War Manual according to which harm to civilians who are in or on military objectives would not prohibit attacks on these objectives.”

Indeed, the category of civilians used as an illustrative example in the DoD Manual — munitions factory workers — are generally considered the paradigmatic case of individuals who must be considered as civilians and treated as such for all law of war matters (including proportionality analysis which can preclude an attack) even though the building in which they work is a lawful military target. (Dinstein 2013 section on “What Is Clearly Not [Direct Participation in Hostilities];” A.P.V.Rogers, Law on the Battlefield (3d ed. 2012); William H. Boothby 2012 at 8.12; United Kingdom, LOAC Manual 2.5.2 & 5.3.3 (2004); Israeli High Court decision para 35 (quoting Gasser, in The Handbook of Humanitarian Law in Armed Conflicts 32 (Dieter Fleck ed. 1995)); Dieter Fleck, “Protection of Civilians,” in The Handbook of Humanitarian Law in Armed Conflicts 32 (Dieter Fleck ed. 4th edition 2021); ICRC Interpretive Guidance on Direct Participation in Hostilities 2009 n.123; ICRC Interpretive Guidance 2008 Summary Report of Expert Meetings, p.83; Interpretive Guidance 2003 Summary Report of Expert Meetings, pp.2-3; Schmitt 2010 718; Henderson 2009 p.222).

It merits highlighting, as Marty Lederman explained in 2016, that the definition of “military objectives” extends far beyond the “munitions factory” example. “Military objectives,” as defined by article 52 of Additional Protocol I to the Geneva Conventions and accepted by the United States, are “those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.” A road, a bridge, an apartment building, a transportation hub — any of these could be a valid military objective depending on their use (and dual use) at the time of attack. Discounting civilians in or near such objectives could largely eviscerate the rule of proportionality.

November 2016: The General Counsel of the Department of Defense delivers public remarks in which she previews forthcoming revised text.

In late November 2016, then-General Counsel of the Department of Defense Jennifer O’Connor gave public remarks previewing the publication of a revised Manual. O’Connor announced significant changes to the Manual’s chapter on civilian harm. Her remarks, however, included an important caveat: even if the proportionality principle applies to civilians working in or on military objectives, “their choice to support military operations in or on a military objective may be weighed by commanders as a factor in the proportionality analysis.” She stated:

[C]ommentators and others have read the Manual and raised questions about how civilians who are proximate to military operations, such as workers in a factory that produces military weapons, are factored into the proportionality analysis. Arguments range from “they should receive full protection as civilians” to “they have forfeited their protections and are entitled to receive none.” The revision of the Manual will clarify that the proportionality principle applies to these civilians, and that feasible precautions must be taken to reduce the risk of harm to them, although their choice to support military operations in or on a military objective may be weighed by commanders as a factor in the proportionality analysis.

November 2016: Leading legal experts criticize the suggested draft revision

This caveat received renewed criticism from leading experts. Janina Dill wrote:

“The dichotomy between civilians and combatants as exhaustive and mutually exclusive categories is the core structuring principle of contemporary IHL. … In turn, a civilian either counts as one civilian in a proportionality calculus or she is herself a legitimate target of intentional attack.

Working in a munitions factory is not only “not direct participation in hostilities”; it is not a lesser version of it either. How then could it affect the level of protection a civilian is legally owed?

Oona Hathaway, Marty Lederman, and Michael Schmitt also addressed the General Counsel’s remarks: “The statement appears to suggest … that if and when civilians or other protected persons ‘choose’ to ‘support military operations in or on a military objective,’ commanders contemplating attacks on legitimate military objectives may discount the value of their lives in the proportionality analysis.” They wrote that such a proposition is unsupported by customary international law, threatens to undermine the central purpose of the proportionality principle (i.e., protecting civilians so long as they are not directly participating in hostilities), and would impose “extraordinary” operational cost on military commanders tasked with implementing it. They wrote:

[I]t sounds as if the idea derives from the following controversial passage in the Bothe, Partsch and Solf commentaries on Additional Protocol I: “It is … doubtful that incidental injury to persons serving the armed forces within a military objective will weigh as heavily in the application of the rule of proportionality as that part of the civilian population which is not so closely linked to military operations.” The Bothe, Partsch and Solf treatise does not, however, cite any state practice or opinio juris as authority for this notion, and we are not aware of any. It does not, for example, appear in allies’ law-of-war manuals, as far as we know. And we do not recall seeing anything like it in any U.S. manual or guide, either. As for practice, if states had decided to adopt such a rule, presumably there would have been extensive discussions among experts as to how to weigh different civilians’ lives. Yet there has been no such discussion.

Indeed, the sparse sentence by Bothe, Partsch and Solf may best be understood not as a statement of law or ethics, but rather a reflection on how actors may in reality apply the proportionality rule in such circumstances. As Ian Henderson wrote in his 2009 book, The Contemporary Law of Targeting: “While some might consider this [sentence by Bothe, Partsch and Solf] an accurate statement of reality, … IHL makes no distinction between classes of civilians. Accordingly, each civilian is ‘worth’ the same as every other civilian.” (But cf. Dieter Fleck, Methods of Combat, Handbook of International Humanitarian Law, 4th edition 2021 (discussing the case of “the deliberate taking of the risk by any civilian who stays in a military installation,” and “[w]hether collateral damage to civilians working in military objectives (and thus contributing to the military endeavour of its state) is of lesser weight in striking a balance with the military advantage than potential damage to ‘innocent’ civilians is a question not yet answered, but which needs careful study. Although an affirmative answer might create serious ethical difficulties, reasons of military practicability (and of soldiers’ common sense) might point in that direction.”))

December 2016: The Department of Defense issues a new version of the Manual and disavows the footnotes as authority for interpreting the text

In December 2016, the Department of Defense released an updated version of the Manual, which received praise from outside experts including for the Department’s willingness to implement changes in response to external criticisms (Lederman 2016) (Goodman 2016) (Corn 2016).

Current version: Department of Defense: Law of War Manual 2016 (revised updated)


“[S]ometimes civilian personnel work in or on military objectives in order to support military operations. … Such persons assume a certain risk of injury.[FN 412] Provided such workers are not taking a direct part in hostilities, those determining whether a planned attack would be excessive must consider such workers, and feasible precautions must be taken to reduce the risk of harm to them. Those making such determinations may consider all relevant facts and circumstances.”

Accompanying footnote no. 412:


“When the attacking force causes harms that are the responsibility of the defending force … due to the employment of civilian personnel in or on military objectives, the responsibility of the defending force is a factor that may be considered in determining whether such harm is excessive.”

Notwithstanding this commendation, Lederman noted that “there remains a lot of important work to be done.” (Lederman 2016). Specifically, Section — the revised version of Section in the 2015 Manual — retained remnants of the problem identified by the outside scholars, namely, the “sliding scale of civilian valuation.”

On the positive side, the text of the Section was amended to explicitly protect civilian personnel working in or on military objectives, and the OGC decided to make no reference in the body of the text to the caveat described by O’Connor. However, a lengthy footnote to the Section suggests that these civilian workers should weigh less in the proportionality analysis (citing and quoting, for example, the controversial Bothe, Partsch and Solf statement). Thus, it seemed that the inclusion of these sources in the footnote did potentially present the caveat as the Department’s view on the law.

But that was decidedly not what the Department wanted to achieve in its revision of the section.

Department officials provided a briefing upon the release of the 2016 Manual in which they gave instructions for how to interpret the footnotes in the Manual. Lederman wrote:

Department of Defense officials explained in a background briefing that readers should not assume the Department approves of, or agrees with, propositions of law contained in the footnotes, including in the new footnotes that raise troubling questions.

Goodman also quoted, with permission, statements by two Department officials who explained the need to discount the legal significance of the footnotes:

“The text is our view of the law, and the footnotes are supporting information that is meant to provide a way for people researching questions” to find “others who have commented on these in other places.” Another Department official agreed “one hundred percent” with that explanation.

“I think it’s important to take these officials at their word concerning the limited authority of the Manual‘s footnotes. One may hope, therefore, that military officers will not pay much heed to the footnotes–at least not for purposes of explicating the laws of war,” Lederman wrote.

The problem, of course, is that the distinction between the text as a view of the law on one hand, and the footnotes as a mere starting point for further research on the other, is not memorialized in the Manual itself, or, to our knowledge, in other DoD guidance. Thus, many Judge Advocates will not read the footnotes with such nuance, but will instead assume the footnotes serve their ordinary purpose: to express, support, and further the legal positions discussed elsewhere in the text.

An important aside: The Department’s statement about how to interpret the footnotes in the Manual applies to other sections as well. Other articles in this Just Security series on other topics will identify some of the most concerning statements in footnotes that may mislead the Manual’s readers.

December 2016: Legal experts raise concerns about the remaining ambiguity and unintended meaning

The current text of the Manual creates a problem in how footnote 412 may be mistakenly used by readers to interpret the Department’s position on the law. If readers misunderstand the relevance and utility of the footnotes, they are also likely to misread and misapply another section of the Manual. Section states:

“When the attacking force causes harms that are the responsibility of the defending force … due to the employment of civilian personnel in or on military objectives, the responsibility of the defending force is a factor that may be considered in determining whether such harm is excessive.”

As Adil Haque has explained, that logic is best understood as a reference to post-strike third-party determinations, or else it surely results in an even more serious and “mistaken[] view of the law” (Lederman 2016).

Read together, however, the current text, including footnotes, presents a significant problem for the Department. Consider, for example, an article in The Military Law and the Law of War Review that walks through each source in footnote 412 of the Manual as an exposition of the Department’s view and naturally finds that result incompatible with the law of armed conflict. The author also discusses the practical consequences:

[T]he Law of War Manual is likely to affect the behavior of U.S. soldiers on the battlefield. … [O]fficers could partially discount from a proportionality calculus the lives of dozens or hundreds of civilian workers for having assumed a risk by working in or on a military objective — even if the civilian personnel continue to be considered civilians.

As Lederman explained, “It is not clear why DoD retained the passage in 5.12.1, and the footnote citations in, even after making its most recent changes to the Manual. The Department should amend or remove them.”

B. Solutions

In her remarks in November 2016, before turning to the discussion of civilian munitions factory workers and like cases, then-General Counsel O’Connor said of the Manual: “We expect to update it periodically because for the Manual to achieve its purpose, it has to be a living document and provide as much clarity on the very tough issues on which these lawyers must provide advice.” Since the December 2016 revisions, the Manual has, however, never been updated.

That said, in March 2022, the Department’s General Counsel Caroline Krass, told Congress that her office will review the Manual’s interpretation of the presumption of civilian status, which was the subject of a previous article in this Just Security series.

With respect to the text of the Manual under discussion here, various options could be pursued, and are mutually reinforcing.

In the immediate term, the OGC could memorialize, as an official addendum to the Manual, what Department officials stated, in the briefing upon the release of the 2016 update, about the intended way to interpret the document’s footnotes. That action would be highly salient, especially given the absence of any updates since 2016, and would more effectively inform U.S. military lawyers and other readers than the current, unsatisfying state of affairs.

Second, the Department could review and scrub the Manual to free it of problematic footnotes. “It would be far preferable for DoD simply to eliminate many of the ‘substantive’ citations and quotations in the footnotes, especially where they merely represent an idiosyncratic or once-stated view of U.S. officials,” Lederman wrote.

Third, the Department could refine the text in sections and to ensure their intended meaning is more clear (see e.g., Lederman n. 2). For the latter section, were it to be retained, the DoD Manual should more closely track the language in the U.K. Law of Armed Conflict Manual (section 5.22) or, even better yet, the language used by APV Rogers, the General Editor of the U.K. manual (which refers to post-strike assessments such as by “any tribunal dealing with the matter”). The text should be written to make clear that civilians in or near munition factories or other military objectives are civilians, full stop. Especially as a guide for lawyers, it should refrain from imprecise and potentially misleading phrases such as the attacking force “must consider” such civilians without more. Given the potential confusion created by the prior versions of the Manual, the DoD Manual could also add a flat statement such as: “the attacking force must apply the standard proportionality rule in assessing whether harm to civilians who work in or on military objectives is excessive.”

The Department would benefit itself and the United States well by addressing these concerns with the Manual. Doing so would also live up to the promise made. For the Manual to achieve its purpose, it needs to be a living document. Periodically updating it to ensure as much clarity as possible would best serve the military lawyers responsible for providing advice to America’s armed forces.