Clearing the Fog of War? The ICRC’s Interpretive Guidance on Direct Participation in Hostilities

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On Tuesday (June 2), the ICRC published a document setting out its “Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law.”  The purpose of the document is to help clarify and to assist in the interpretation of a principle which is well accepted in international humanitarian law (IHL) but subject to much ambiguity. This is the principle that civilians are to be immune from direct attacks by the parties to an armed conflict unless the civilian takes a direct part in hostilities. The principle is codified in Article 51(3) of Additional Protocol I (1977) to the Geneva Conventions (1949): “Civilians shall enjoy the protection [from direct attack] . . ., unless and for such time as they take a direct part in hostilities.” The Israeli Supreme Court held in Targeted Killings Case (2005) that this provision in its entirety is a reflection of customary international law (para. 30).  The principle regarding immunity of civilians from attack except in cases of direct participation in hostilities is a key component of the principle of distinction – which requires belligerents to distinguish between civilians and combatants. The principle of distinction and notion of direct participation in hostilities addresses the most most fundamental question in wartime: who can be targeted in an armed conflict? Therefore an attempt to clarify these principles is of great importance and should help in clearing the fog of war?

Despite agreement on the principle that civilians who take a direct part in hostilities are subject to direct attack by the adversary, there has been much difficulty in applying it. Even the basic question of who is a civilian is one where answers have been unclear – particularly in non-international armed conflicts. There is little guidance on what the words “direct participation” mean and on when a person is to be considered as no longer taking a direct part in hostilities so that he again benefits from civilian immunity. It is clear that a civilian who takes up arms and uses it offensively will be taking a direct part in hostilities. It is also certain that the concept of direct participation extends beyond those who bear arms. But how far? Does it extend as far as those who provide logistical support for persons who bear arms or those who provide intelligence? These questions have assumed increased importance in recent years because of the changing nature of armed conflict, and in particular, the increasing involvement of civilians in armed conflict. These changes result partly from the increase in asymetric conflicts with non-State actors but also from the increased use of civilians (eg private contractors) even by States in the general war effort. As a result of these trend it is essential that these questions regarding when civilians may be targeted in war are clarified.

The ICRC has worked on its Interpretive Guidance for a number of years and convened a series expert meetings in the course of its work (see reports here). However, the final document is not intended to reflect the view of the experts, who all contributed to the process in their individual capacities. Rather, this document sets out the official views of the ICRC on the topic. Prior to this ICRC document, some guidance on the notion of direct participation in hostilities (or DPH) was to be found in the ICRC Commentary on AP I and in the Targeted Killings Decision (2005) of the Israeli Supreme Court.

The ICRC’s interpretive guidance attempts to answer 3 questions:

  • Who is considered a civilian for the purposes of the principle of distinction?
  • What conduct amounts to direct participation in hostilities?
  • What modalities govern the loss of protection against direct attack? [In short when is a person considered as no longer taking a direct part in hostilities, how is that determined and what are the consequences]
Who is a Civilian?
As a matter of treaty law, the question of who is a civilian for the purposes of the principle of distinction (and the law relating to targeting) is relatively clear with regard to international armed conflicts but is quite uncertain in the case of non-international armed conflicts. This is because API provides a definition for international armed conflicts but while Part IV of Additional Protocol II (dealing with non-international armed conflicts) uses the term “civilian” it does not provide a definition. In the Interpretive Guidance, the ICRC provide different definitions of the concept of civilian for international and non-international armed conflict.

I. The concept of civilian in international armed conflict: For the purposes of the principle of distinction in international armed conflict, all persons who are neither members of the armed forces of a party to the conflict nor participants in a levée en masse are civilians and,  therefore, entitled to protection against direct attack unless and for such time as they take a direct part in hostilities.

II. The concept of civilian in non-international armed conflict: For the purposes of the principle of distinction in non-international armed conflict, all persons who are not members of State armed forces or organized armed groups of a party to the conflict are civilians and, therefore, entitled to protection against direct attack unless and for such time as they take a direct part in hostilities. In non-international armed conflict, organized armed groups constitute the armed forces of a non-State party to the conflict and consist only of individuals whose continuous function it is to take a direct part in hostilities (“continuous combat function”).

The definition of civilian in international armed conflicts is basically a restatement of Art. 50(1) of API. In the commentary to the Interpretive Guidance (pp. 21-23), the ICRC makes the important point that members of irregular groups that belong to the State but who do not fulfil the conditions in Art. 4(A)(2) for prisoner of war status will nevertheless be members of the armed forces of the State and are therefore not civilians for the law relating to the conduct of hostilities. This must be right and one would suspect that State practice bears this out. In any case, such persons would be part of the armed forces of a State under Art. 43 of AP I.
With regard to non-international armed conflicts, the ICRC makes a distinction between members of the armed forces of a State and of the armed forces of non-State groups. Only those who assume a continuous combat function are said to be members of organized armed forces of a non-State party. One possible criticism of this distinction is that it creates a lack of equality between the State and non-State forces. Any member of the armed forces of a State is a legitimate target at all times, including the cook, the cleaner and the lawyer. However, for non-State forces individuals who do not have a continuous combat function will be civilians and therefore immune from direct attack unless they engage in a specific act which amounts to direct participation in hostilities, and only for such time. Another approach might simply have been to provide that any member of an organized armed group is not a civilian and then try to define what membership means. However, the problem with this would be how one defines the organised armed group. Does organised armed group refer to the broad organization involved in the fight (eg Hamas, Hezbollah, the IRA?) or merely to the fighting wing of the group? The ICRC is clearly trying to confine the definition to the fighting wing but the difficulty is how one defines that wing when there will likely be few formal indicia to define the fighting wing. So rather than have two definitional problems – (i) defining the armed group and (ii) defining membership – it is easier to focus simply on the membership question (which is itself very difficult) and to let that define the group. Anyone who continuously takes a direct part in hostilities is clearly a part of the fighting wing of the group . Beyond that, with groups who don’t wear uniforms or have other external indicia of membership, it will be difficult to know if other persons (who don’t have a continous combat function) are parts of the armed/fighting wing of a broader group.  So, I think the ICRC have taken a pragmatic approach rather than one dictated by logic. But that is not a bad thing. Especially as persons who don’t have a continuous combat function can still be targeted in instances where they take a direct part in hostilities, and can be detained for violating domestic or international law.
What Constitutes Direct Participation in Hostilities?
The key part of the ICRC’s Interpretive Guidance is the attempt to define direct participation. The relevant priniciples are set out as follows:

V. Constitutive elements of direct participation in hostilities: In order to qualify as direct participation in hostilities, a specific act must meet the following cumulative criteria:

1. The act must be likely to adversely affect the military operations or military capacity of a party to an armed conflict or, alternatively, to inflict death, injury, or destruction on persons or objects protected against direct attack (threshold of harm), and

2.There must be a direct causal link between the act and the harm likely to result either from that act, or from a coordinated military operation of which that act constitutes an integral part (direct causation), and

3. The act must be specifically designed to directly cause the required threshold of harm in support of a party to the conflict and to the detriment of another (belligerent nexus).

In essence, the direct participation is defined as engaging in an act or taking part in a military operation which directly causes, and is intended to cause, harm to the military of the adversary or to protected persons or objects. The first constitituve element of this definition – threshold of harm – goes beyond the Commentary on AP I which had defined direct participation overly narrowly. That commentary stated that:

‘direct’ participation means acts of war which by their nature or purpose are likely to cause actual harm to the personnel and equipment of the enemy armed forces.

However, as the Israeli Supreme Court correctly noted this was too narrow as it appears to exclude acts intended to cause damage to civilians (eg suicide bombings) and such acts should be regarded as hostile acts.

The second element – direct causation – is really the key principle in this area. To lose protection, civilians may either engage in acts which directly cause harm or engage in an operation which directly causes harm.  In the commentary to the Interpretive Guidance, the ICRC states that:

In the present context, direct causation should be understood as meaning that the harm in question must be brought about in one causal step. Therefore, individual conduct that merely builds up or maintains the capacity of a party to harm its adversary, or which otherwise only indirectly causes harm, is excluded from the concept of direct participation in hostilities. For example, imposing a regime of economic sanctions on a party to an armed conflict, depriving it of financial assets, or providing its adversary with supplies and services (such as electricity, fuel, construction material, finances and financial services) would have a potentially important, but still indirect, impact on the military capacity or operations of that party. Other examples of indirect participation include scientific research and design, as well as production and transport of weapons and equipment unless carried out as an integral part of a specific military operation designed to directly cause the required threshold of harm. Likewise, although the recruitment and training of personnel is crucial to the military capacity of a party to the conflict, the causal link with the harm inflicted on the adversary will generally remain indirect. Only where persons are specifically recruited and trained for the execution of a predetermined hostile act can such activities be regarded as an integral part of that act and, therefore, as direct participation in hostilities. (pp. 52-53)

The ICRC has taken a narrow view of the scope of direct participation. In my view, this is right approach to take.  A narrow interpretation is suggested by the text and structure of the provisions which deal with direct participation in hostilities. The text of the relevant provisions speak not of participation in armed conflict but of participation in hostilities, something narrower than being involved in the conflict in general. Participation in hostilities suggest participation in military operations. Furthermore, participation must be “direct”. So not all participation in military operations means loss of protection from attack.

In general the ICRC approach on what constitutes taking a direct part is similar to the approach taken, on this question, by the Israeli Supreme Court in the Targeted Killings case (paras. 34-37). Both seem to come to the same conclusions with regard to examples given (perhaps apart from voluntary human shields). However, the main contribution of the ICRC’s work is that provides the analytical tools by which to reach those answers.

Loss of Protection

It is to be recalled that Article 51(3) of AP I states that civilians lose protection from direct attack only “for such time” as they take a direct part in hostilities. In the Targeted Killings case, the Israeli Supreme Court dismissed the argument of the Israeli government (and a view shared by the US) that the “for such time” part of the provision does not reflect customary international law. This leads to the question when direct participation ceases.

In keeping with the narrow approach to direct participation, the ICRC takes the view that loss of protection from attack only arises for so long as the civilian is engaged in the specific act which amounts to direct participation.

VII Temporal Scope of Loss of Protection: Civilians lose protection against direct attack for the duration of each specific act amounting to direct participation in hostilities, whereas members of organized armed groups belonging to a non-State party to an armed conflict cease to be civilians (see above II), and lose protection against direct attack, for as long as they assume their continuous combat function.

This means that the ICRC rejects the notion of continuous direct participation. This is the idea that a person who takes a direct part in hostilities remains a valid target until he opts out of the hostilities through extended non-participation. On this view, such a person is always subject to attack even in the periods when not specifically engaging in the hostile act. This view is contrary to the narrow notion of direct participation in hostilities adopted by the ICRC. However, the ICRC was willing to broaden slightly the notion of the specific act which constitutes taking a direct part in hostilities. It stated that:

VI Beginning and End of Direct Participation in Hostilities: Measures preparatory to the execution of a specific act of direct participation in hostilities, as well as the deployment to and the return from the location of its execution,  constitute an integral part of that act.

The ICRC’s apparent rejection of the notion of continous direct participation does not, in most cases, change the results one would get if one adopted a continous direct participation analysis. In most cases, adopting either approach would probably mean that the revolving door of participation causes the person to lose immunity, even beyond the specific occasions when he acts. All that is changed is the category into which the person falls. This is because the person is would probably be, on the ICRC’s analysis, a member of an organized armed group and thus subject to direct attack for so long as he is a member. Recall that membership in such group is defined as a person who assumes a continous combat function. So applying, the ICRC analysis one would arrive at the same conclusion as the Israeli  Supreme Court when it said:

On the other hand, a civilian who has joined a terrorist organization which has become his “home”, and in the framework of his role in that organization he commits a chain of hostilities, with short periods of rest between them, loses his immunity from attack “for such time” as he is committing the chain of acts.  Indeed, regarding such a civilian, the rest between hostilities is nothing other than preparation for the next hostility. Targeted Killings Case, para. 39

The only difference is that on the ICRC’s analysis (and assuming a non-international armed conflict), the person would not be a civilian but rather a member of an organised armed group.

Where there is a key difference is when the person concerned is not a member of an armed group but, rather, acts independently or where there is an international armed conflict and the group does not belong to a party to the conflict. The ICRC’s analysis would lead to the view that the person concerned is not continously subject to attack but only when he acts.

Does IHL Require a Capture rather than Kill Approach?

What may be the most controversial aspect of the ICRC’s approach in the Interpretive Guidance is the penultimate principle:

IX. Restraints on the use of force in direct attack: In addition to the restraints imposed by international humanitarian law on specific means and methods of warfare, and without prejudice to further restrictions that may arise under other applicable branches of international law, the kind and degree of force which is permissible against persons not entitled to protection against direct attack must not exceed what is actually necessary to accomplish a legitimate military purpose in the prevailing circumstances.

This principle suggests that even if one reaches the conclusion that a person is one of those that IHL says may be targeted, a party to a conflict must as a general matter consider whether it is necessary to do so. In other words, where it is possible to disable the threat from that person by several means, the party to the conflict should use the least harmful means can be employed taking the circumstances into account. This principle is said to be based on a general principle of military necessity which stipulates that belligerent parties can only take such action as is necessary to overcome the other party, even if the proposed action is not prohibited by principles of IHL. So if a person can be captured rather than killed, there is an obligation to do so even in cases where the person is not a civilian or where he is a civilian taking a direct part in hostilities.

This view of the law finds support in the Targeted Killings case (para. 40). However, it is not certain that that Court was seeking to apply principles of IHL. It cited the ECHR’s decision in McCann v. United Kingdom, 21 E.H.R.R. 97 (1995). It is therefore likely that this least harmful means approach is an importation from human rights law.  The argument that IHL does take this approach is one made by the author of the ICRC’s Interpretive Guidance, Dr Nils Melzer in his monograph – Targeted Killing in International Law (OUP, 2008, pp. 278 and ff). In Melzer’s view, the principle of military necessity not only has a permissive function but also has a restrictive function.  In his view, this restrictive function is a general principle which underlies all of IHL and which means that even when specific principles of IHL do not forbid action that action is forbidden where not justified by military necessity. Thus military necessity acts as an additional level of restraint on belligerents in addition to specific rules of IHL.

There is some support for this general view of military necessity in military manuals (eg the UK, the German manuals, the Lieber Code as well as the US’ Commanders Handbook on the Law of Naval Operations). However, the question is whether in the context of targeting IHL hasn’t already made the calculation as to what is necessary from the military perspective. In other words, the view may be taken that IHL has already determined the range of persons against whom lethal force may be used and this determination is already based on ground of military necessity. Therefore no further restraints exist.


All in all, the main contribution of the ICRC in this area is to provide analytical tools in an area where they have long been lacking. There has long been broad agreement on the verbal expression of the key principles here and even agreement on how the principles may play out in particular cases. What we have lacked is how we get from the former to the latter. Lacking that roadmap we lose our way when we try to get other results where instinct alone does not help us. Now we have some tools for doing so.

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Cara says

May 14, 2012

A really helpful analysis. A quick note regarding your section on restraints on the use of force - the guidance says that this 'does not necessarily imply a legal obligation to capture rather than kill' (page 78).