The July 2023 Revision of the DoD Law of War Manual and Customary International Law
Customary international law (CIL) is an important source of legally binding rules applicable in armed conflict. Where a party to a conflict has not ratified a key international humanitarian law (IHL) treaty, such as the 1977 Protocol (I) Additional to the Geneva Conventions of 12 Aug. 1949, Relating to the Protection of Victims of International Armed Conflicts (AP I), that party may need to turn to CIL to determine the applicable rules. Further, even where all parties have ratified key treaties, CIL may fill in gaps not explicitly addressed in the treaties.
The U.S. Department of Defense (DoD) Law of War Manual includes a number of references to existing CIL. Generally, these references reiterate longstanding U.S. government positions on what is and is not CIL. However, in the July 2023 revision of the Manual, the drafters stated that a newly-revised provision of the Manual, which adopted certain presumptions applicable when there is doubt whether a person or object is targetable, reflects CIL in the view of the DoD. This statement is remarkable considering the longstanding position of the United States that these presumptions do not reflect CIL.
In this post, I ask whether the statement about the DoD view actually creates a new rule of CIL for the United States. Without taking a position on the merits of the rule, I suggest that the U.S. government should clarify this point and consider adopting guidance for the future should the drafters of the Manual want to make additional claims that provisions of the Manual represent CIL rules.
Customary International Law
According to Section 102 of the Restatement (Third) of the Foreign Relations Law of the United States, CIL results from “a general and consistent practice of States that is followed by them from a sense of legal obligation.” This sense of legal obligation is referred to as opinio juris sive necessitatis or simply opinio juris. In theory it can be found in affirmative statements by States explaining that they believe they are bound under international law to take or abstain from certain actions. However, while State practices can be observed, it is not often that States provide such affirmative statements explaining their legal rationale for these practices. Thus, as noted in Section 1.8 of the Manual, identifying CIL rules may be a “difficult inquiry.”
The importance of correctly identifying CIL cannot be overstated. CIL is binding on States and applies even where treaties do not. Thus, once a rule becomes CIL, it applies universally (with a limited exception for States that persistently objected to the formation of the CIL rule as it developed). Further, while a State may adopt an internal law at variance from CIL, that cannot excuse a breach of CIL under international law. For example, per Article 3 of the Articles on Responsibility of States for Internationally Wrongful Acts, domestic law cannot render lawful non-compliance with applicable international law.
2023 Revision to DoD Law of War Manual
In July 2023, Section 5.4.3.2 of the Manual was revised to include, among other things, the following statements:
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.
[I]f 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 (emphasis added).
These statements bring the United States into closer alignment with two key provisions of AP I, specifically Article 50(1) (“In case of doubt whether a person is a civilian, that person shall be considered a civilian”) and Article 52(2) (“In 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 action, it shall be presumed not to be so used”).
Importantly, the statements in revised Section 5.4.3.2 of the Manual represent a significant change from the position taken in the Manual prior to the July 2023 change. Before the July 2023 revision, Section 5.4.3.2 said that “[u]nder customary international law, no legal presumption of civilian status exists for persons or objects.” The language in the prior version of Section 5.4.3.2 reflected the U.S. government’s longstanding opposition to the presumptions in AP I, as articulated in a 1985 study conducted by the Joint Chiefs of Staff:
The presumption of civilian status established by Articles 50 and 52 of the Protocol could adversely impact on American military operations and personnel in many ways. “War crimes” accusations have been a principal means used to deny prisoner of war status to Americans in both Korea and Southeast Asia; the existence of a rule that everyone and everything is civilian in case of “doubt” could be used to prove such charges in the future, or at least lend credence to them for propaganda purposes. A requirement that there be no “doubt” that the persons and objects attacked were military could also be used to place American prisoners of war on the psychological defensive during interrogation. This presumption also provides an additional protection for guerrillas and other irregulars who may find it advantageous to be presumed a civilian rather than a combatant. Finally, such a presumption would make it more difficult to defend the legality of military operations in domestic and international public opinion.
The 2023 change in the Manual’s treatment on presumptions has been discussed at length in a series of excellent blog posts (see here, here, here, here, here, here, here, here, here and here). I do not intend to add more to the discussion of the merits of the change. Rather, I want to focus on the following statement in the new Section 5.4.3.4 included in the 2023 revision (emphasis added):
The discussion in § 5.4.3.2 (Classifying Persons or Objects as Military Objectives When Planning and Conducting Attacks) reflects the DoD view of customary international law applicable to assessing whether persons or objects are military objectives, including in cases of doubt, when planning and conducting attacks.
In my view, this statement underlines how significant the change in the DoD position on presumptions is. The DoD has not only adopted the presumptions (with many qualifiers, in an attempt to ensure they are workable in practice) as part of the Manual’s guidance for military practitioners, but has also completely reversed its position on the presumptions’ CIL status. While various experts made the case for the DoD to make this change (e.g., here and here), there can be no doubt that the DoD’s decision to amend the Manual is a major development in the progressive development of the U.S. view of CIL applicable to armed conflict.
Is DoD’s View an Expression of Opinio Juris of the United States?
The statement on CIL in new Section 5.4.3.4 raises two important questions.
First, is the statement regarding CIL made on behalf of the United States? The language is less than clear because the statement only says it is an expression of “DoD’s view.” Does that mean that other parts of the executive branch, up to and including the President, could hold other views or even disagree with DoD? Possibly, given the following language in Section 1.1.1 of the Manual:
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.
Further, in her statement at the time the July 2023 revision was issued, the DoD General Counsel noted that “[t]he Department-wide Manual reflects the views of the Department of Defense and does not necessarily reflect the views of the U.S. Government as a whole.” Finally, while DoD Directive 2311.01, the DoD’s internal law of war directive, indicates that the Manual is promulgated under the authority of the DoD General Counsel, I cannot find any provision of the U.S. Code or implementing regulations that delegates to the General Counsel any authority to bind the United States under international law.
Second, if the statement in new Section 5.4.3.4 is intended to be a statement on behalf of the United States, what is its legal effect? Section 1.1.1 of the Manual includes an important caveat on this point: “This manual represents the legal views of the Department of Defense. This manual does not, however, preclude the Department from subsequently changing its interpretation of the law.”
Given this disclaimer, one could argue that if any provision of the Manual is subject to future change, it is questionable that any statement in the Manual, including revised Section 5.4.3.2, actually reflects a binding expression of opinio juris.
Notwithstanding these two considerations, it is likely that experts both within and outside the U.S government will conclude that the statement in Section 5.4.3.4 is, in fact, the definitive U.S. position on the CIL status of the presumptions. After all, the DoD is the U.S. government executive agency that is most significantly involved with the application of IHL, and as the proponent of the Manual, the DoD has taken the lead in articulating the U.S. government’s view on IHL. Further, the General Counsel’s statement on the July 2023 revision indicates that the changes to the Manual were subject to consultations with other executive branch agencies, which means that other agencies had an opportunity to comment and, if necessary, object. Given the lack of evidence that there were any objections, there is no reason to believe that the “DoD view” is not the U.S. government view.
Did the Manual Abandon the United States’ Usual Approach to CIL?
It is very striking that the language in the new Section 5.4.3.4 affirmatively asserts that revised Section 5.3.2.2 reflects CIL. This suggests the DoD has already concluded that all the requirements for the formation of CIL rules on the presumptions have been met. This differs from the usually cautious approach taken by the United States towards CIL. In March 2011, for example, the Obama White House issued a fact sheet on its policy regarding the treatment and prosecution of individuals held at the detention facility at Guantanamo Bay, which included the following statement:
Article 75 of Additional Protocol I, which sets forth fundamental guarantees for persons in the hands of opposing forces in an international armed conflict, is similarly important to the international legal framework. Although the Administration continues to have significant concerns with Additional Protocol I, Article 75 is a provision of the treaty that is consistent with our current policies and practice and is one that the United States has historically supported.
Our adherence to these principles is also an important safeguard against the mistreatment of captured U.S. military personnel. The U.S. Government will therefore choose out of a sense of legal obligation to treat the principles set forth in Article 75 as applicable to any individual it detains in an international armed conflict and expects all other nations to adhere to these principles as well.
Subsequently, in response to a written question from the Senate Foreign Relations Committee, the State Department’s Legal Adviser confirmed that the U.S. government’s statement about complying with the principles of Article 75 was adopted after a “comprehensive interagency review” and was “likely to be received as a statement of the U.S. Government’s opinio juris as well as a reaffirmation of U.S. practice in this area.” Importantly, the Legal Adviser did not view the statement in the White House fact sheet as an acknowledgment that a CIL rule already exists:
Determining that a principle has become customary international law requires a rigorous legal analysis to determine whether such principle is supported by a general and consistent practice of states followed by them from a sense of legal obligation. Although there is no precise formula to indicate how widespread a practice must be, one frequently used standard is that state practice must be extensive and virtually uniform, including among States particularly involved in the relevant activity (i.e., specially affected States). The U.S. statement, coupled with a sufficient density of State practice and opinio juris, would contribute to creation of the principles reflected in Article 75 as rules of customary international law, which all States would be obligated to apply in international armed conflict.
The cautious approach taken by the White House in March 2011 is more in line with how CIL actually evolves, with individual countries making a contribution to the development of a CIL rule but the rule forming over time. Therefore, it is typically hard for one State to simply assert that a rule is CIL without very clear evidence in terms of opinio juris and dense international practice to demonstrate that other States agree. This point was made clear, at length, by the Bush Administration in a letter to the International Committee of the Red Cross published in 2007 regarding U.S. concerns about ICRC’s Study of customary IHL.
In the case of the statement in new Section 5.4.3.4, however, the DoD appears to have made a definitive conclusion about CIL. This is presumably because it believes that the rules reflected in revised Section 5.4.3.2 are sufficiently supported by opinio juris and State practice to justify a claim that CIL rules now exist, notwithstanding DoD’s long history of objecting to the presumptions.
Interestingly, in the ICRC’s 2005 Study of customary IHL, the ICRC did not adopt, as a black letter rule, either of the presumptions found in articles 50 and 52 of AP I. Instead, the Study discussed the presumptions in its commentary to two long-standing rules of distinction:
Rule 6. Civilians are protected against attack unless and for such time as they take a direct part in hostilities.
Rule 10. Civilian objects are protected against attack, unless and for such time as they are military objectives.
In its commentary to these provisions, the ICRC noted various interpretations of the presumptions among States that have signed AP I and interpretations by States that have not signed, including the (now abandoned) rejection of presumptions by the United States. The lack of unanimity among States regarding the presumptions presumably is the reason the ICRC did not include the presumptions in its list of CIL rules.
Some experts may downplay the significance of the DoD’s statement regarding CIL in Section 5.4.3.4 on the grounds that the presumption applicable to objects is identical to a presumption of civilian status for certain objects found in Article 3(8) of the 1996 Amended Protocol II to the Convention on the Use of Certain Conventional Weapons (CCW), which deals with the use of landmines, booby-traps and other devices. The United States ratified this treaty in 1999, and an article-by-article analysis of Amended Protocol II accompanying President Clinton’s 1997 communication to the Senate about the treaty stated that the prohibition on indiscriminate use of weapons found in Article 3(8) was “already a feature” of CIL applicable to weapons. However, it is a stretch to say that this “feature” comment in the analysis referred to the presumption language in Article 3(8) because the analysis did not even mention the presumption:
Paragraph 8 [of Article 3] prohibits indiscriminate use of mines, booby-traps and other devices and defines such use as placement which: (a) is not aimed at a military objective as defined in Article 2, or (b) employs a method or means of delivery which cannot be directed at a specific military objective, or (c) may be expected to cause incidental loss of civilian life or damage to civilian objects excessive in relation to the direct military advantage anticipated. This prohibition is already a feature of customary international law that is applicable to all weapons.
It also notable that this reference to a “feature” of CIL—which certainly would have represented a change in the U.S. position on the presumption—did not merit a mention in either the ICRC’s 2005 customary IHL Study or in the prior versions of the DoD’s Manual, when each was issued in June 2015 and revised in May 2016 and December 2016. If the United States was really saying in 1997 that the presumption of doubt was in fact a “feature” of CIL, it would have attracted attention in these publications. Thus, it appears more likely than not that the DoD’s position on the CIL status of the presumptions in the July 2023 revision of the Manual is a new development and not part of a gradual evolution of the U.S. position.
Implications of the CIL Status of Revised Section 5.4.3.2
If revised Section 5.4.3.2 of the Manual is CIL for the United States, there are real world consequences. For example, the DoD will need to adjust doctrine and training to reflect that these requirements are legally binding and not simply a “best practice.” Indeed, if revised Section 5.4.3.2 reflects CIL, a deviation from its language could arguably represent a violation of international law. Therefore, commanders, operators, and planners need to understand that there could be consequences from a failure to comply with revised Section 5.4.3.2.
Revised Section 5.4.3.2 could also impact the implementation of important policies directed at protecting civilians, including the February 2023 Memorandum on United States Conventional Arms Transfer Policy and the December 2023 DoD Instruction on Civilian Harm Mitigation and Response. Among other things, these policies are intended to ensure that countries who either receive weapons from the United States or partner with the United States in military operations comply with IHL. If revised Section 5.4.3.2 reflects CIL, then an ally’s failure to comply will need to be addressed by the United States.
Conclusion
The object of this post is not to question the merits of revised Section 5.4.3.2 as guidance for targeting in armed conflict. Rather, the point is that the Manual’s elevation of the guidance, including its treatment of presumptions, to the level of CIL is a truly remarkable development given the DoD’s long-standing opposition to the presumptions as CIL.
An important question that needs to be answered is whether revised Section 5.4.3.2 represents binding CIL for the United States (i.e., is the “DoD’s view” shared by other relevant agencies in the U.S. government?) While some may think there could be a political or legal advantage to leaving this point ambiguous, the U.S. position on the scope of CIL is too important to leave open for speculation by governments, courts, tribunals, and academics.
Finally, given this example of a Manual change resulting in the formation of CIL for the United States, it would be useful for the U.S. government to clarify how far the Manual’s drafters have the authority to include new statements of opinio juris for the United States in future amendments of the Manual. It may, for example, make sense to adopt a formal interagency approval process (rather than rely on a consultative process) for such statements to ensure that the legal effect of changes to the Manual is clearly understood. Alternatively, the White House may want to withhold authority to make such statements to the President so that references in the Manual regarding CIL, which do not have Presidential approval, are understood as not constituting expressions of opinio juris binding on the United States for the purposes of formation of new CIL rules. In any case, the U.S. government’s process for embracing rules as CIL needs to be carefully considered because of their binding and enduring nature once these rules are formed.
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James (Jim) A. Schoettler, Jr. is an Adjunct Professor at the Georgetown University Law Center.
Photo credit: U.S. Army, Sgt. Jose Lora