Avril McDonald[1]
April 2004
2.1  Defining civilians and civilian status
2.2  Threats to the principle of distinction
2.3.1  Contemporary trends in armed conflicts
2.3.2  The civilisation of the military  The privatization of formerly military functions
2.3.3  Terrorism and counter-terrorism
3.1  What is meant by the term ‘hostilities’?
3.2  What is meant by the term ‘direct participation in hostilities’?
3.2.1  Which types of activities constitute direct participation?  To what extent is the intention of the participant or the results achieved relevant?
3.2.2. Which types of activities do not constitute direct participation?
3.2.3  Grey areas
3.2.4  The temporal element
3.2.5  In order to directly participate in hostilities, must there be a nexus with the armed conflict?
3.2.6  In order to directly participate, does the civilian have to be a member of or have a link with a party to the conflict?

Most of the casualties of modern conflicts, as is well known, are mainly civilians and not soldiers. When these casualties are reported, the word ‘civilian’ is often prefaced by the adjective ‘innocent’, with the suggestion being that there are other civilians who are not so innocent, and whose deaths or injuries are not as unfortunate and haphazard as might at first appear.
As a general principle, civilians are entitled to protected status under international humanitarian law and may not be attacked. Moreover, the greatest of care must be exercised in conducting military operations in order to minimize civilian casualties. However, the laws of war recognize that some civilians are more innocent and deserving of protection than others, and that those who take a direct part in hostilities during an armed conflict forfeit their protected status and may be attacked. Article 51(3) of the 1977 First Protocol Additional to the 1949 Geneva Conventions (Additional Protocol I) encapsulates this principle of protection, and its conditionality: ‘Civilians shall enjoy the protection afforded by this section, unless and for such time as they take a direct part in hostilities.’
Notwithstanding this recognition in the law that civilians do not always deserved protected status, international humanitarian law applicable during armed conflicts is premised on a fundamental assumption that war fighting is the work and privilege of soldiers and that civilians are generally to be considered as protected persons, at a remove from and not involved in hostilities. While this supposition may have reflected the actuality of armed conflict prior to the adoption of the four Geneva Conventions in 1949, it was already becoming divorced from reality by the time of the adoption of the Additional Protocols to the Geneva Conventions in 1977 and today increasingly seems a quaint and archaic notion, out of step with the reality of today’s wars.
The main fruit of the 1974-1977 Diplomatic Conference leading to the adoption of the Additional Protocols was Additional Protocol I applicable in international armed conflicts, which were even by then becoming increasingly uncommon. Additional Protocol II, applicable in non-international armed conflicts, is a pale shadow of that achievement, inadequate to regulate all or many aspects of such conflicts, even though they were already becoming the norm amongst armed conflicts, and responsible for the greater proportion of civilian casualties.
While Additional Protocol I recognizes the traditional distinction between combatants and civilians,[2] Additional Protocol II?largely for political reasons[3]?does not acknowledge the concept of combatancy during non-international armed conflicts. Thus, aside from members of a state’s armed forces, all persons taking up arms during a non-international armed conflict are legally civilians and not combatants. Given that the vast majority of conflicts around the world today are non-international in character, this means that the majority of persons engaged in fighting them (or at least those fighting as part of armed opposition groups against states) have no privileged combatant status under international humanitarian law and are technically ‘unlawful’ or ‘unprivileged’[4] combatants, that is, they are civilians who are unlawfully engaged in combat and who may be punished for that fact alone by the national authorities.[5] As there is no legal distinction between combatants and civilians during a non-international armed conflict, fulfilment of the fundamental rule of protection of genuine civilians during a non-international armed conflict depends on an understanding of what actions trigger a loss of civilians’ protected status and expose them to legitimate attack.
Even in an international armed conflict distinguishing between combatants and genuine civilians is in reality not always easy or clear-cut. As states’ armed forces come to rely on civilians to perform an increasing number of roles formerly the preserve of military personnel, the odds of a civilian being involved in conflict, both directly and indirectly, have dramatically increased. Decisive may be not the fact of wearing a uniform and carrying arms (although in many cases, civilians do) but the nature and degree of an individual civilian’s involvement in hostilities.
In relation to both non-international and international armed conflicts, therefore, as well as other types of conflict which international humanitarian law does not yet recognize, it is essential for the sake of upholding the principle of protection of the so-called innocent civilian population to identify criteria to assist in determining when an individual civilian crosses the rubicon and becomes a de facto (if not a de jure) combatant, with all the consequences that implies.
The exercise is complex and there are many uncertainties. It is beyond the scope of this working paper to attempt any comprehensive analysis of the problem or to propose considered solutions; that will require a far more in depth analysis of the relevant legal issues and study of the roles that civilians play in contemporary conflicts.[6] This paper will confine itself to attempting to identify and briefly comment on some of the legal problems arising out of the phenomenon of increased civilian participation in hostilities.
Part 3 of the paper will therefore explore the following main legal questions: What is meant by the term ‘direct participation in hostilities’? Which types of activities constitute direct participation, and which types of activities do not? Which are some of the gray areas? Is there a required mental element for direct participation? What is the temporal duration of direct participation in hostilities (i.e., the time during which unlawfully participating civilians may be attacked)? What, if any, link must there be between a civilian participant and both an armed conflict and a party to the conflict?
Part 4 will then examine some of the consequences of direct participation. What if any residual protection do civilians who take a direct part in hostilities enjoy under international humanitarian law and international human rights law when they lose their protected status? What is the status of civilians who unlawfully participate in hostilities upon capture? To what extent are civilians who directly participate in hostilities criminally liable, including for war crimes, under international humanitarian law? Finally, Part 5 draws a few conclusions.
Before turning to the substantive legal questions, some preliminary matters must be addressed by way of background. In Part 2, therefore, the relevance and fundamental importance of the principles of distinction and protection are outlined, followed by a brief examination of some contemporary threats to these norms.

The principle of distinction is one of the foundation stones upon which the edifice of international humanitarian law rests. As Fenrick has stated: ‘Military commanders are obligated to distinguish between civilian objects and military objectives and to direct their operations against military objectives.’[7]
The principle of distinction was expressed as early as 1868 in the St. Petersburg Declaration in the following words: ‘That the only legitimate object which States should endeavour to accomplish during war is to weaken the military forces of the enemy.’[8] In other words, no military necessity justifies direct attacks on civilians or civilian objects. Respect for the principle is what makes it possible for humanitarian law to fulfil its aim of protecting the civilian population from the consequences of armed conflict. According to Watkins: ‘The ability of combatants to plan and conduct their operations and defend the state, as well as the capacity of a state or the international community to hold them accountable for failure, is significantly dependant upon the clarity and relevance of the distinction principle.’[9]
Several key provisions of The Hague Regulations annexed to the 1907 Fourth Hague Convention, the 1949 Geneva Conventions and their Additional Protocols of 1977 enshrine the principle of distinction between civilians and civilian objects and military objectives.
Article 25 of The Hague Regulations prohibits the attack or bombardment, by whatever means, of towns, villages, dwellings or buildings which are undefended. Article 27 states: ‘In sieges and bombardments all necessary steps must be taken to spare, as far as possible, buildings dedicated to religion, art, science or charitable purposes, historic monuments, hospitals and places where the sick and wounded are collected, provided they are not being used at the time for military purposes.’[10]
The whole thrust of the Fourth Geneva Convention of 1949 is towards providing for the protection of civilians and civilian objects, in particular Part II concerning the General Protection of Populations Against Certain Consequences of War, and a number of provisions provide specific protection from attacks against civilian objects, including Article 18 prohibiting attacks on civilian hospitals[11] and Article 33 concerning collective punishment and reprisals against protected persons and their property.[12]
Additional Protocol I augments these provisions of the Geneva Conventions, without replacing them.[13] The additional protections are set out in Part IV ? Civilian Population ? of the Additional Protocol. Article 48 of Additional Protocol I ? Basic Rule ? has already been alluded to.[14] It is supplemented by the very detailed Article 51,[15] which sets out specific rules concerning the protection of the civilian population against military operations; Article 52,[16] which addresses general protection of civilian objects; Article 53, which protects cultural and religious property; Article 54, which addresses protection of objects indispensable to the survival of the civilian population; Article 55, which addresses protection of the natural environment; and Article 56, which concerns protection of works and installations concerning dangerous forces. Other articles in Part IV focus on other ways to increase the protection of the civilian population, by, for example, the obligation to take precautions in attacks (Article 57) and against the effects of attacks (Article 58). Articles 59 and 60 concern localities and zones under special protection. 
Support for the principle of distinction has also come from other sources. Resolution XXVIII adopted by the 20th International Conference of the Red Cross and Red Crescent, held in 1965 in Vienna, declared that all governments and other authorities responsible for action in armed conflict should, inter alia, conform to the principle that distinction must be made at all times between persons taking part in the hostilities and members of the civilian population to the effect that the latter be spared as much as possible. The International Court of Justice, in its Nuclear Weapons Advisory Opinion, stated that the principle of distinction between combatants and non-combatants is one of the cardinal principles of international humanitarian law, and that ‘these fundamental rules are to be observed by all States whether or not they have ratified the conventions that contain them, because they constitute intransgressible principles of international customary law’.[17]
2.1  Defining civilians and civilian status

While the Fourth Geneva Convention of 1949 is exclusively devoted to the protection of the civilian population, it contains no definition of civilian. Under Article 4 of the Fourth Convention, persons protected by it are those who, at a given moment and in any manner whatsoever, find themselves in case of a conflict or occupation, in the hands of a Party to the conflict or Occupying Power of which they are not nationals.[18] Article 3 indicates that during non-international armed conflicts the persons who enjoy protection against the various forms of violence and infringement mentioned are ‘[p]ersons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat by sickness, wounds, detention or any other cause, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria.’ 
The first attempt in international humanitarian law to identify who are civilians came in 1977 with Article 50 of Additional Protocol I (read together with Article 4(A) of the Third Geneva Convention and Article 43 of the First Additional Protocol). And yet, Article 50(1) avoids giving any definition of civilians and instead defines civilians in the negative: civilians are all persons who are not combatants. Paragraph 1 provides that civilians are persons who are not (1) members of the armed forces of a Party to the conflict, as well as members of militias or volunteer corps forming part of such armed forces; (2) members of other militias and members of other volunteer corps, including those of organized resistance movements, belonging to a party to the conflict and operating in or outside their own territory, even if this territory is occupied, provided that such militias or volunteer corps, including such organized resistance movements, fulfill the four conditions of combatancy.[19] The aforementioned combatants qualify for prisoner of war (POW) status upon capture. Thus, civilian is a residual category: whoever is not a combatant shall be deemed to be a civilian. But, ‘In case of doubt whether a person is a civilian, that person shall be considered to be a civilian’. (Article 50(1) ‘The civilian population comprises all persons who are civilians’ (Article 50(2)). Significantly from the perspective of protection of the civilian population: ‘The presence within the civilian population of individuals who do not come within the definition of civilians does not deprive the population of its civilian character.’ (Article 50(3)
Other sources similarly adopt a negative approach to defining civilians. The United States Annotated Supplement to The Commander’s Handbook on the Law of Naval Operations, for example, defines non-combatants as ‘individuals who do not form a part of the armed forces and who otherwise refrain from the commission or direct support of hostile acts’.[20] Watkins notes that
‘that term also includes a more diverse mix of persons such as medical officers, corpsmen, chaplains, contractors, civilian war correspondents and armed forces personnel who are unable to engage in combat because of wounds, sickness, shipwreck or capture (ie. POWs). Here, “non-combatant” is used in the context of those persons, civilian and military, who should not be targeted and not in the sense of the combatant/civilian distinction.’[21]
The quid pro quo for the special protected status enjoyed by civilians is that they are strictly prohibited from participating in hostilities?except in the exceptional case where they are participating in a levee en masse, in which case they shall be regarded as belligerents provided that they carry their arms openly and respect the laws and customs of war[22]?and if they do, they lose the protections of the Fourth Geneva Convention and the Additional Protocols safeguarding civilians from attack (although, as shown in Part 4, they are not devoid of protection). However, legally, civilians who unlawfully participate in hostilities are not transformed into combatants, even for the duration of their unlawful participation and even if they de facto fulfil some of the conditions of combatancy, such as carrying their arms openly and respecting the laws and customs of war. They are what has become known colloquially as ‘unlawful combatants’ or ‘unlawful belligerents’, that is, they remain civilians, albeit ones who are unlawfully participating in hostilities.
International humanitarian law applicable in non-international armed conflicts does not explicitly distinguish between combatants and civilians (as it does not recognize combatant status) yet it does recognize that persons who do not take part in hostilities retain their protected status as civilians (and implies that those who do, lose it). Under Article 4(II) of Additional Protocol II:
‘All persons who do not take a direct part or who have ceased to take part in hostilities, whether or not their liberty has been restricted, are entitled to respect for their person, honour and convictions and religious practices. They shall in all circumstances be treated humanely, without any adverse distinction. It is prohibited to order that there are no survivors.’
Equally, Additional Protocol II provides that those civilians who do unlawfully participate in hostilities shall lose their protected status as civilians. Article 13(3) provides: ‘Civilians shall enjoy the protection afforded by this Part, unless and for such time as they take a direct part in hostilities.’
2.2  Threats to the principle of distinction

The principle of distinction is a corollary of the principle of protection: without the former, the latter is impossible to uphold. However, the paradigm of lawful combatants on the one side, engaged in fighting, and innocent civilians on the other side, not involved in and protected from hostilities, hardly reflects the reality of conflict today, if it ever did. The sanctity of the principles of distinction and protection is threatened by a number of contemporary phenomena. Several particularly significant ones deserve mention.
2.3.1  Contemporary trends in armed conflicts

As noted above, the distinction between combatants and civilians is rooted in international humanitarian law applicable in international armed conflicts, conflicts which comprise a very small minority of contemporary armed conflicts. Further, today’s non-international armed conflicts barely conform to the model envisaged by international humanitarian law for such conflicts. The principle of distinction is rarely observed in practice in such conflicts. Such conflicts may not be confined to the territory of a single state, yet international humanitarian law does not recognize or regulate non-international armed conflicts fought between various armed groups on the territory of more than one state, or the challenge to international peace and security presented by localized or transnational terrorism. It is unclear whether it recognizes the possibility of an armed conflict that is fought by an armed opposition group against a state not of its nationality, or various other possible permutations of conflict, which are no longer merely theoretical possibilities.
Clausewitz’s trinitarian model of war, as a battle fought between sovereign states, which are composed of a government, an army and the people, seems increasingly anachronistic in a world in which many conflicts involve clashes between opposing ethnic, racial or religious groups within one or more states, or where the goal of the fighting does not conform to the Clausewitzian view of military strategy as the continuation or advancement of (the state’s) political ends[23] but may be driven by rivalry amongst groups for control over scarce resources, or by religious or ethnic hatred or competition, etc.[24] In such conflicts, the ambition may not be a resolution of and end to the conflict in one’s favour but the continuation of instability and lawlessness in order to promote a climate which allows business interests to thrive and criminality to flourish. Simmering, low-level conflicts in some states and regions can provide a cover for lucrative organized crime, including trafficking in drugs, arms and people.[25]
In some countries, the government has lost the monopoly on violence. Armed opposition groups may pose a threat to state security, and where a state does not exercise full control over its territory, warlords or criminal syndicates often yield de facto authority. Many states today suggest that their security is even more threatened by terrorists, in particular the possibility of terrorists yielding weapons of mass destruction or so-called ‘dirty bombs’, than by other states, although the exaggeration of the threat for political ends cannot be discounted.
There is also the effect of shifting allegiances and identities to consider: civilians within a state may have transferred their primary allegiance from their state of nationality or residence to a religion or to a non-state actor. This may in some states be exacerbated by the fact that the relationship between states and their citizens is in reality often far removed from the Weberian ideal.
2.3.2  The civilisation of the military

The past decades have seen the increasing civilianization of the military in many states, but especially in the United States, home to the world’s most powerful military, and the involvement of civilians in many former military tasks.[26] Civilians are increasingly recruited to design, manufacture, maintain and operate several weapons systems and are involved in some tasks that could potentially be considered as direct participation in hostilities when carried out in the context of an armed conflict. This is confirmed by the US Department of the Army, which stated that:
‘Historically, civilians have played an important role in the conduct of U.S. military operations. More recently, Army civilians have established themselves as an integral and vital part of America’s Army team. With distinction, they perform critical duties in virtually every functional facet of Combat Support and Combat Service Support, both at home and abroad. Serving beside their deployed uniformed compatriots they also provide the critical skills necessary to assure the availability of essential combat systems and weaponry; thereby maximizing the fighting capability of the combat soldier and success of the Army wartime and emergency missions.’[27]
A significant factor driving civilianization is cost. It is considered that ‘the transfer of functions performed by military personnel to civil service personnel is one way to save costs while affecting force effectiveness minimally’.[28] Research carried out by the RAND Corporation found that ‘civilization can produce cost savings under many, but not all, circumstances’.[29] Civilians come without their families and the perceived need for the same support structures as military personnel. Civilians receive less investment in training and education. In particular, they can be employed on flexible terms, as the need arises. Downsizing or upsizing of civilian employees is much easier than of military employees. Of course, the lack of investment in civilian personnel, including in their education and training, could also have negative consequences.
Technology is another factor driving civilianization. Advances in weapons technology outpace the ability of the military to train its own. Some weapons systems come as ‘package deals’, which include maintenance, training and even operation by civilians.[30] As some states, in particular the USA, come to rely increasingly on high-tech and computer-driven warfare, reliance on civilian experts will only increase.
Due to the technological advantage it enjoys in conducting war, the US currently has the luxury of being able to strike targets thousands of miles away, but yet enjoy relative immunity from counter-attack. Thus, the consequences that its widespread and growing civilisation of the military has for the concept of direct participation have not yet become fully manifest: the chickens have not yet come home to roost. The civilians who maintain and operate its weapons systems that are used in combat in Iraq, for example, and who may be located a continent away from the targets that they strike probably do not consider that they are directly participating in hostilities in Iraq, although probably they are, and they remain for the moment immune from attack given the limited capabilities of Iraq or the various resistance groups which the coalition is fighting. But had Iraq been able to launch long-range missiles at such targets in the US, it would be difficult to argue that it was doing anything other than striking legitimate military targets.
Finally, it is important to note that some civilians deployed in combat situations are physically almost indistinguishable from military personnel. They may wear uniforms, body armour, helmets, etc. Even though US civilians working for the military have to wear a distinguishing patch on their uniform, this would hardly be sufficient to avoid the enemy confusing them with combatants.[31] The privatization of formerly military functions

The trend in recent years has been away from direct employment of civilians by the armed forces and towards privatisation or corporatiation of the military. In the US, inter alia, many formerly military functions have been privatised, in particular, logistics and maintenance functions.[32] The Armed Forces have contracts with hundreds of defense contractors, which provide an array of services. Many military subcontractors are former military personnel. Although now civilians, they are hired because of their military training, often to engage in tasks requiring military skills and which raise the question of their direct participation in hostilities. According to Ricks:
‘Faced with the need to cut personnel, and seeking to preserve its war-fighting “tooth,” the post-Cold War military has sought to privitize much of its support “tail.” This privitization, which promises to reduce the number of soldiers in civilian occupations, is occurring not only on U.S. soil, where maintenance work is being farmed out to corporations, but also in other countries where U.S. soldiers operate.’[33]
According to Markusen:
‘Since the 1970s, the share of American defense effort performed directly by members of the armed forces and Pentagon-employed civilians has declined substantially, while that performed by employees of private sector firms has risen, for everything from whole weapons system to operations support and troop training. Since the mid-1990s, politically well organized constituencies have pressed for more privitization. In the past two years, the Pentagon has accelerated its efforts to outsource under the rubric of the Revolution in Military Business Affairs and has begun experimenting with military training contracts in selected international spheres of operation.’[34]
Today, civilian subcontractors are engaged in a wide range of services for the military in the US and elsewhere, including: operations planning; maintenance and logistics expertise; computer and communications technical support; weapons manufacture, maintenance and operations; engineering; information and electronic warfare operations; space operations; intelligence gathering and analysis; scientific research and development; security; administration, managerial and logistical support; humanitarian aid delivery; fire fighting; catering; and mail delivery. In fact, there is almost no area of the US Armed Forces where civilian subcontractors do not play a vital role.
2.3.3  Terrorism and counter-terrorism

Terrorism constitutes a fundamental and deliberate attack on the principles of distinction and protection. Indeed, not only do some terrorists demonstrate a lack of precision and precaution in their tactics or a cavalier attitude to civilian safety, often their very purpose and aim is to attack civilians and inflict as much damage, suffering and fear as possible. Terrorists who attack civilians within the context of an actual armed conflict are civilians unlawfully participating in hostilities, if they have a nexus to the armed conflict, and terrorism constitutes a war crime.[35]
What is prohibited during warfare in a fortiori prohibited during peacetime. Terrorist attacks against civilians in peacetime, while not violations of international humanitarian law (which does not apply, as the conditions precedent for its application do not exist) are prohibited under international criminal law and the national criminal law of every state.
While nothing justifies callous terrorist attacks on civilians, unfortunately sometimes counter-terrorist reactions of states are equally blunt. States reacting to terrorist violence often overreact and demonstrate a less than exemplary regard for the principles of distinction and protection of the innocent civilian population.
The noticeable tendency by some states during the ‘war on terror’, particularly the USA, to apply conduct of hostilities rules to attacks against terrorists undertaken outside the context of an armed conflict also challenges the principle of distinction. Peacetime security operations are becoming increasingly militaristic, and states are justifying resort to lethal force against civilians, for example, on the grounds that the latter are ‘directly participating’ in terrorism. Increasingly, states are asserting that, when faced with an unconventional and ruthless enemy, such as terrorists, new methods of policing and combat and an unconventional military response may be required. In the new security environment, the lines between war and peace are blurred, and civilians are becoming targeted in operations which are military in all but name. By the same logic, the persons involved in fighting the war on terror, who are mainly civilians, could be considered to be directly participating in these ‘hostilities’. For example, the CIA was responsible for the operation conducted in Yemen whereby an unmanned military drone fired a hellfire missile at a car carrying six suspected terrorists.[36]

It should be noted at the outset that great uncertainty surrounds several aspects of the concept of direct participation by civilians in hostilities, and this area of the law merits close examination. The need for clarity is obvious, given the serious consequences that result from unlawful participation and the danger to innocent civilians posed by unlawful combatants. Not only does the unlawful participant jeopardise his or her own security and safety but he or she potentially exposes other civilians to danger, directly and through contributing to a weakening of the principle of distinction.
3.1  What is meant by the term ‘hostilities’?

Hostilities has a narrower meaning than armed conflict. According to the Dictionary of the International Law of Armed Conflict, hostilities means ‘an act of violence by a belligerent against an enemy in order to put an end to his resistance and impose obedience’.[37] Needless to say, the hostilities must occur within the context of an armed conflict, whether international and non-international. The term ‘armed conflict’ refers to the sum of the hostilities, from the outbreak of conflict to its resolution. Hostilities are violent incidents occurring within that timeframe.
The term hostilities has both a temporal and a material aspect. Regarding the former, hostilities covers both the time spent in the preparation for, the execution of and the return from an attack. According to the authoritative ICRC Commentary on the Additional Protocols: ‘It seems that the word “hostilities” covers not only the time that the civilian actually makes use of a weapon, but also, for example, the time that he is carrying it, as well as situations in which he undertakes hostile acts without using a weapon.’[38]
Regarding the material aspect, hostilities covers acts of war which are specifically intended by their nature or their purpose to hit the personnel and the materiel of the armed forces of the adverse Party.[39]
3.2  What is meant by the term ‘direct participation in hostilities’?

To take a direct part in hostilities is usually taken to mean to engage in a specific attack or attacks on an enemy combatant or object during a situation of armed conflict. Article 49(1) Additional Protocol I explains that: ‘Attacks’ means acts of violence against the adversary, whether in offence or defence.’ The ad hoc International Criminal Tribunal for the Former Yugoslavia (ICTY) in its judgement in Prosecutor v. Krnoljelac said that: ‘An “attack” can be defined as a course of conduct involving the commission of acts of violence. The concept of “attack” is distinct and independent from the concept of “armed conflict”. In practice, the attack could outlast, precede, or run parallel to the armed conflict, without necessarily being a part of it.’[40]
Both the terms ‘direct’ and ‘active’ participation in hostilities occur in Geneva law, although it can be questioned whether there is any substantive difference between them. Many commentators use these terms interchangeably.[41] According to Dinstein: ‘In essence, taking an active part in hostilities (which negates the status of civilians) implies participation in military operations.’[42]
The jurisprudence of the ad hoc International Criminal Tribunal for Rwanda (ICTR) indicates that there is no substantive difference between the terms ‘active’ and ‘direct’. In the Akayesu Trial Judgement, the Trial Chamber found that these terms should be treated synonymously.[43]
3.2.1  Which types of activities constitute direct participation?

According to the ICRC Commentary on Additional Protocol I: ‘Direct participation in hostilities implies a direct casual relationship between the activity engaged in and the harm done to the enemy at the time and place where the activity occurs.’[44] The Commentary on Additional Protocol II states in a similar vein that: ‘The notion of direct participation in hostilities implies that there is a sufficient casual relationship between the act of participation and its immediate consequences.’[45]
But, in fact, this view, like the term ‘direct participation in hostilities’ itself is somewhat misleading as it suggests that only direct participation in a literal sense in activities amounting to attacks or which enable the launching of attacks on an enemy are covered. On the contrary, it is generally and increasingly considered that there are many activities which involve a more indirect role for civilians, where the civilian is one or more steps (geographically or temporally) away from the actual application of violence (which may be virtual rather than physical) and may not even consider him or herself to be a direct participant in hostilities, and which do not actually involve attacks in the literal or kinetic sense, or where the causality relationship is more indirect, yet which are also considered as direct participation in hostilities.
One can observe that at both ends of a spectrum of activities lie acts about which there appears to be consensus or at least little controversy that they constitute direct participation in hostilities or that they do not. It is those that lie somewhere in between that give rise to uncertainty.
Before focusing on the difficult cases, it is useful to first identify what are generally considered as clear-cut cases of direct participation by civilians in hostilities. According to Kalshoven: ‘’[T]o take a direct part in hostilities’ must be interpreted to mean that the person in question performs hostile acts, which, by their nature or purpose, are designed to strike enemy combatants or materiel; acts in other words, such as firing at enemy soldiers, throwing a Molotov-cocktail at an enemy tank, blowing up a bridge carrying enemy war materiel, and so on.’[46] The US Navy manual states:
‘Civilians who take a direct part in hostilities by taking up arms or otherwise trying to kill, injure, or capture enemy personnel or destroy enemy property lose their immunity and may be attacked. Direct participation may also include civilians serving as guards, intelligence agents, or lookouts on behalf of military forces. Direct participation in hostilities must be judged on a case-by-case basis. Combatants in the field must make an honest determination as to whether a particular civilian is or is not subject to deliberate attack based on the person’s behavior, location and attire, and other information available at the time.’[47]
A person who delivers ammunition within combat zones is generally considered to be directly participating in hostilities.[48] Yet, in this case, these persons are not themselves directly participating in an actual attack, but engaging in an activity which makes possible the direct participation in an attack by another person. Still, they are considered by most authorities to be legitimate military targets for the duration of their participation.
Civilians do not have to be located in the zone of hostilities or bear arms themselves in order to be considered as direct participants in hostilities and as subject to attack themselves. Where civilians are involved in operating weapons systems during situations of hostilities, even where they are at a geographical remove from the zone of hostilities, they can be considered as directly participating. For example, civilians manning computers which remotely control drones flying over foreign territory, gathering intelligence, selecting targets, or engaging in attacks, could certainly be considered to be directly participating in hostilities. Civilians involved in computer network attacks against an enemy could also be said to be directly participating in attacks.
The essential contribution that certain civilians make to the war effort may render them targetable. For example, certain civilians participating in strategic weapons programs, and at a geographical remove from the hostilities, could be considered as directly participating in hostilities and liable to attack. In 1989, a US memorandum of law concerning the prohibition of assassination stated:
‘The technological revolution in warfare that has occurred over the past two centuries has resulted in a joining of segments of the civilian population with each nation’s conduct of military operations and vital support activities. ? one rule of thumb with regard to the likelihood that an individual may be subject to lawful attack is his (or her) immunity from military service if continued service in his (or her) civilian position is of greater value to a nation’s war effort than that person’s service in the military.’[49]
The memorandum gives the example of civilian scientists occupying key positions in a weapons program that is regarded as vital to a state’s national security or war effort. It noted that the participation of civilians in the Manhattan Project (more than 90 percent of the staff were civilians) was of such importance that they could have been considered as liable to attack.
Mike Schmitt has proposed a ‘criticality’ test, specifically ‘the criticality of the act to the direct application of violence against the enemy’.[50] He states that ‘an individual performing an indispensable function in making possible the application of force against the enemy is directly participating. In other words, the appropriate test is whether that individual is an integral facet of the uninterrupted process of defeating the enemy.’[51] To what extent is the intention of the participant or the results achieved relevant?

It was stated above that some persons who might be considered as direct participants in hostilities might not actually be aware of their participation, begging the question, to what extent is the civilian’s state of mind relevant. What type of mens rea must a civilian possess in order to be considered as a direct participant in hostilities? It seems that one necessary mental element is that the civilian participant must intend to gain a military advantage or cause harm to the enemy. Indeed military responses to unlawful civilian involvement in hostilities acknowledge that there must be a certain intention on the part of the civilian who participates. This is clear even from the Commentaries to the First Additional Protocol, which states that direct participation encompasses ‘act which by their nature and purpose are intended to cause actual harm to the personnel and equipment of the armed forces’.[52]
Suppose that a civilian peace activist in a state under occupation decides to destroy the enemy’s fighter planes, not in a bid to further the war effort (i.e., consciously to attain a military advantage) but for the opposite reason: in order to make a political protest against war and occupation and prevent the use of those planes for attacks on civilians. Is such a person taking a direct part in hostilities or engaging in an act of civil disobedience (albeit one that is a crime)? Most if not all military persons would argue?and correctly, it is submitted?that such an action constitutes direct participation in hostilities, as the destruction of the planes causes harm to the enemy and has a direct military consequence for the armed forces, as it lessens their ability to wage war.
In this respect, while ‘intention’ is important, it is the intention to participate (that is, to engage in the activities actually engaged in and to cause harm or gain a military advantage by doing so) that is important, not the political or other motivation underlying the participation. In the above example, the civilian protester clearly intends to engage in actions that produce the result (the destruction of the planes). Whether his motivations are ‘positive’ (he is really peace-loving) or negative , while not entirely irrelevant to the decision to target him, would not render him immune from attack, and in any case, such ‘subjective’ intentions are in many cases impossible to discern: in this sense, objective intention, as in the intention to participate in hostilities, must be distinguished and separated from (possible political) subjective motivation.
Another question to consider is to what extent the impact of participation of a civilian in hostilities should be considered. That is, should a results-oriented approach be adopted or an objective intention-oriented approach (in the narrow sense used above) or both? This is particularly relevant with regard to the choice of weapon used.[53] Arguably, the results of the participation should not be determinative of a civilian’s participation. When the question of whether or not an individual civilian is considered to be directly participating in hostilities is made contingent on the actual effects achieved, it leaves too much to chance. If a civilian lobs a hand grenade at a soldier during an armed conflict, few would argue with the proposition that he intends to inflict serious injury or harm and is a direct participant in hostilities. His objective intention is discernable from the choice of weapon used. If the hand grenade misses its target and ends up in a river, is the civilian’s act any less illegal, or is he any less of a (future) military threat?
What if a child throws a stone at a soldier on patrol during a situation of occupation? In this case, the choice of weapon could indicate a certain intention (or lack of) on the part of the assailant. If he had wanted to participate in hostilities and thereby inflict actual harm, he might better have chosen a Molotov cocktail. The fact that he has chosen as his weapon a stone could mean that he merely intends to express his dissatisfaction with the occupation. Still, accidents can happen and it is possible that the stone could strike the soldier in the head, inflicting a mortal blow. Should his bad luck in killing the soldier (a results-oriented approach) magically transform him from a protester into a war criminal? A child who fires a Molotov cocktail at a soldier might reasonably expect to inflict serious harm on the recipient. Yet, fate might intervene, and the Molotov cocktail could miss its target.
These examples hopefully illustrate that there are difficulties with a results-oriented approach. For one thing, it leaves too much to chance: a civilian may intend to directly participate, with the goal of achieving a military advantage, but he may fail in his attempt, or even be less successful than he had hoped. But for all that, he is no less of a direct military threat, including an ongoing threat. Indeed, his initial failure may simply spur him on to try again.
Apropos the example of the child throwing a stone, one can argue that a child is not in a position to form the necessary intention to directly participate in hostilities, and the presumption vis-à-vis every minor should be that they are not direct participants unless there is a preponderance of evidence to the contrary (which the use of weapon could signify). It should also be mentioned that any military response, even to a direct attack, must be proportionate. Even if the child is concerned to be a direct participant in hostilities, a proportionate response (one that is informed by the rules of international humanitarian law) would not involve the use of live fire or even plastic bullets.
While it can validly be argued that in the cut and thrust of a situation of armed conflict, there is simply no time to look at the intention motivating an act, the idea is not to try and read the minds of civilians engaged in hostilities but to discern their intention from the available evidence, on a case-by-case basis. This seems indeed to be consonant with the above-quoted US Navy Manual, which enjoins combatants in the field to judge each action on its own merits, and consider all the available information at the time before reacting. Clearly, wars can only be waged and responses calibrated based on visible and discernable action, not on the unknown (and possibly unknowable) intention of an assailant. Bearing in mind that where reactive force is used, it must be proportionate and militarily necessary, one could argue that where a civilian’s clear (on its face) intention is not the gaining of a military advantage or the infliction of harm on the enemy, he is probably not directly participating in hostilities.
3.2.2. Which types of activities do not constitute direct participation?

While, as noted above, making an essential contribution to the war effort could involve a civilian in direct participation, a non-essential contribution to the general war efforts (e.g., by supplying foodstuffs to combatants) is not tantamount to active participation in hostilities.[54] Thus, working in a munitions factory, supplying food to combatants, transport of food or humanitarian supplies, etc. are not considered to constitute direct participation. According to A.P.V. Rogers:
‘Taking a direct part in hostilities must be more narrowly construed than making a contribution to the war effort and it would not include taking part in arms production or military engineering works of military transport.’[55]
Combatants clearly rely on the munitions made in the factories where civilians work and are equally dependent on the food they are supplied with. But in this case, the causality is too remote, and there is also no objective intention on the part of these civilians to participate. The civilian does not intend to harm the enemy by his actions or to gain any military advantage.
Notwithstanding the importance of certain key scientists to a military effort, most civilian scientists working for the military could not be considered as directly participating in hostilities where they are merely participating in the war effort. However, where by their work civilians put their own lives in danger, they cannot claim the protection against attack. As Kalshoven points out: ‘civilians cannot enjoy protection from attack when they enter military objectives (e.g., by working in a military base or in a munitions factory) or accompanying military units. This protection is diminished even when civilians merely live near ? or pass by ? a military objective, by dint of the very tangible danger of a legitimate collateral damage in case of attack.’[56]
3.2.3  Grey areas

There are numerous grey areas as concerns the question of civilian participation in hostilities and this working paper can only point out a few.
Among those activities giving rise to particular concern include intelligence gathering, rescue operations and the defensive use of force.
Regarding intelligence gathering, Dinstein distinguishes between a person who gathers military intelligence in enemy-controlled territory and a civilian who retrieves intelligence date from satellites or listening posts, working in terminals located in his home country.[57] The former, in his view, would be a direct participant, while the latter would not. Yet, what is really the essential difference between them? These days, vital intelligence, including target identification, may be gathered by drones remotely controlled by civilians located thousands of miles away. Such a person may not be ‘directly’ participating in as much as he may not actually be engaged in carrying out a direct attack, but the information he gathers makes that attack possible, and without it, it would not be possible to attack that target. There is a clear link and causality can be shown. He is as much of a direct participant?and his contribution to the war effort is just as vital?as the person who drives the truck that delivers ammunition in a war zone. As warfare becomes increasingly technologically sophisticated, it seems almost quaint to adjudge the question of one’s direct participation in it based on one’s proximity to a possibly non-existent physical battlefield.
As the waging of war comes to increasingly rely on civilians (and actually, in many cases, simply could not be conducted without the civilian contribution), the distinction between supporting the war effort and making an essential contribution to the war effort is becoming increasingly strained. One determinant could be: does the civilian make such an essential contribution to the war effort that without him or her, the attack could not be carried out? A danger with such an approach is that it might implicate in direct participation the civilians employed by the armed forces who themselves may not realise that they are directly participating?at least in particular attacks. This is why the mental element ? the objective intention to participate ? is so important to establish.
As regards rescue operations, the US Air Force Commander’s Handbook states that
‘rescue of military airmen downed on land is a combatant activity that is not protected under international law. Civilians engaged in the rescue and return of enemy aircrew members are therefore subject to attack. This would include, for example, members of a civilian air auxiliary, such as the U.S. Civil Air Patrol, who engage in military search and rescue activity in wartime.’[58]
However, the Handbook notes that the care of the wounded on land and the rescue of persons downed at sea or shipwrecked are protected activities under international law.
It should be pointed out, however ? and particularly so given the increased resort to civilians to do formerly military work ? that in reality, civilian crews are used to rescue military personnel downed on land; indeed, Iraq provides more than one example of this. Legally, these civilian subcontractors are unlawfully directly participating in hostilities?and particularly so if they have to conduct the rescue operation under fire?yet, the safety of army personnel (and the accomplishment of the mission) may depend on such direct participation. Clearly, the putting of civilian subcontractors in harm’s way for the sake of force protection without clarifying their legal status and the extent to which they can use force for the rescue and protection of their military comrades is unacceptable.
Another related gray area ? in fact more than in law ? concerns the defensive use of force. While international humanitarian law permits some civilians to carry arms, and in exceptional circumstances to use arms during situations of armed conflicts, the situation regarding military subcontractors is oblique. They are allowed to carry arms and use force in personal self-defence, and it is clear that the latter should be interpreted narrowly. Use of force in defense of combatants (i.e., force protection) arguably constitute direct participation. According to the US Army Field Manual, contractor employees
‘cannot take an active part in hostilities but retain the inherent right to self-defense. Because of their civilian background, they may posses neither the training nor experience to actively participate in force protection measures, and the rules governing warfare preclude them from doing so except in self-defense’.[59]
Schmitt has argued ? correctly, it is submitted ? that  ‘[g]ray areas should be interpreted liberally, i.e., in favour of finding direct participation’,[60] given that an underlying purpose of the law is to enable distinction to be made between combatants and civilians.
3.2.4  The temporal element

Article 51(3) of Additional Protocol I indicates that the protection lost by civilians when they take a direct part in hostilities is temporary, although the phraseology is somewhat circular and does not really help to elucidate just how long that period is. It provides, as mentioned earlier, that civilians lose their protected status ‘for such time as they take a direct part in hostilities’, while not enlightening on what is encompassed by taking ‘a direct part in hostilities’. The Commentaries to the First and Second Additional Protocols suggest that direct participation by civilians in hostilities should be interpreted narrowly.[61] Many scholars consider it to have a temporal limitation which ends once the unlawful attack has been carried out and the assailant has returned home. It is widely considered that during the period of either preparing for and executing the attack and returning home ? and only during this period ? the civilian may be lawfully attacked using military force. According to Kalshoven:
‘Although certainly lacking on this point, military logic suggests that the period indicated by these words encompasses both the time during which the civilian is obviously approaching the chosen target with a view to carrying out his hostile act (although one should be aware here of the rule on cases of doubt in Article 50(1)) and the time he needs to withdraw from the scene after the act.’[62]
The Commentary on Additional Protocol II notes, in relation to the temporal aspect, that the civilian who is directly participating in hostilities may be attacked ‘for as long as his participation last. Thereafter, as he no presents any danger for the adversary, he may not be attacked.’[63]
The assumption here?as explicitly made in the Commentary?is that once the attack has been carried out and the assailant has returned home, he no longer poses a military threat which must be neutralized using military force. Given the principle that the least force necessary to achieve one’s military or law enforcement objectives ought to be employed, a person who has already carried out an attack and who longer poses a military threat (at that moment), should be neutralized using the least force possible. That means that an individual who has earlier posed a military threat by virtue of his or her direct participation should be arrested rather than attacked using military force, where this is possible. In contrast, a combatant is at all times considered to be a legitimate military objective, even while off duty or asleep in bed.
The above reasoning, while sound in principle, does not necessarily square with the nature of modern conflict.  Indeed, this temporal limitation vis-à-vis civilian who take a direct part in hostilities seems increasingly artificial and impractical, and could even at times be at odds with what might be presumed to be the underlying military and law enforcement goals of reducing the security threat presented by unlawful civilian participation in hostilities and upholding the principles of distinction and protection.
The difficulty lies not so much with the civilians who carry out once off attacks on military objectives but with civilians, including terrorists operating in situations of armed conflict, who are committed to ongoing attacks against military or civilian targets. It is difficult to argue that such a person no longer poses a military threat just because he has walked through his front door after an attack, where his intention to directly participate in future attacks has been stated or can be inferred from all the surrounding circumstances (again, the objective intention). A sleeping committed terrorist or rebel who is committed to armed struggle against an opponent poses just as potentially lethal a military threat as the sleeping combatant. The Israeli government has argued, at times not without some justification, that the principle of distinction might be better observed by a targeted military attack on a sleeping terrorist than by attacking him while he is walking home through a busy street in the middle of the day. While this should not be interpreted as an endorsement of the Israeli policy of targeted assassination[64] ? and it is recognised that in reality drawing a line between legitimate attacks on unlawful combatants and unlawful assassinations may be very difficult ? it does seem that the generally accepted view of the temporal limitation at least deserves re-examination. A strict adherence to the temporal limitation (with the participation ending once the civilian returns home) may not always be the most efficacious, or the one best designed to maximize respect for the principles of distinction and protection of truly innocent civilians. All circumstances should be looked at, including the ability of the respondent to employ other means to neutralize the threat, its control over the territory where the civilian assailant is to be found, necessity (in the context of self-defense) and the proportionality of the military response. It may not, for example, be possible to arrest a terrorist or an unlawful combatant in cases where the state that is attacked does not control the territory where the civilian is operating.
The generally accepted temporal limitation also requires states to react quickly, which could lead to unfortunate results. It may not be possible to gather the intelligence necessary to identify the assailant in time to attack him while he is still on the job or returning home from it. A targeted attack after the fact based on firm intelligence could lessen the possibility of mistaken identity.
Undoubtedly, the subject is complex, politically incendiary and fraught with difficulties which cannot be fully explored here. But if the purpose of identifying the temporal duration of loss of immunity is the minimization or neutralization of the military threat posed by an individual civilian while he is directly participating in hostilities (by allowing him to be attacked during these ‘windows of opportunity’), then what seems important in fact are the (ongoing) objective intentions and military capabilities of the civilian, rather than the fact of particular incidents of unlawful participation. Arguably, an individual civilian whose commitment to the unlawful use of armed force is demonstrable and ongoing should be targetable until such time as he or she has clearly renounced such a commitment, and is no longer considered to pose a military threat. The burden of proof could be put on the individual civilian with respect to whom the objective intention to participate has been demonstrated to show that he renounced that intention and is longer committed to direct participation in attacks. This approach is also supported by Schmitt, who writes: ‘Once an individual has opted into the hostilities, he or she remains a valid military objective until unambiguously opting out. This may occur through extended non-participation or an affirmative act of withdrawal.’[65]
On the other hand, where there is no objective evidence that a civilian has directly participated in hostilities or intends to participate in future attacks, the burden of proving that such an individual can be attacked should lie with the power wishing to do so. In any event, before any policy of reaction to unlawful civilian participation is implemented, all the possible implications of removing or altering the temporal limitation would need to be explored, to ensure that this would not be a case of the medicine being worse than the disease.
3.2.5  In order to directly participate in hostilities, must there be a nexus with the armed conflict?

In order to participate directly in hostilities, there should be some link between the individual civilian participant and the armed conflict, i.e., the act should not be undertaken for purely private reasons. During a situation of armed conflict, a man who shoots his neighbour because of an argument about money is committing a criminal act, but as the killing is unrelated to the conflict he could not be said to be directly participating in hostilities or, beyond that, committing a war crime.
This conclusion seems to be confirmed?if only by deduction?by the recent jurisprudence of the ICTY and ICTR. In the Tadić case, an ICTY Trial Chamber stated that: ‘For a crime to fall within the jurisdiction of the International Tribunal, a sufficient nexus must be established between the alleged offence and the armed conflict which gives rise to the applicability of international humanitarian law.’[66] The Chamber elaborated on the necessary link:
‘It would be sufficient to prove that the crime was committed in the course of or as part of the hostilities in, or occupation of, an area controlled by one of the parties. It is not, however, necessary to show that armed conflict was occurring at the exact time and place of the proscribed acts alleged to have occurred, as the Appeals Chamber has indicated, nor is it necessary that the crime alleged takes place during combat, that it be part of a policy or of a practice officially endorsed or tolerated by one of the parties to the conflict, or that the act be in furtherance of a policy associated with the conduct of war or in the actual interest of a party to the conflict; the obligations of individuals under international humanitarian law are independent and apply without prejudice to any questions of the responsibility of States under international law. The only question, to be determined in the circumstances of each individual case, is whether the offences were closely related to the armed conflict as a whole.’[67]
In Aleksovski, the Trial Chamber found that: ‘Not all unlawful acts occurring during an armed conflict are subject to international humanitarian law. Only those acts sufficiently connected with the waging of hostilities are subject to the application of this law. ? It is necessary to conclude that the act, which could well be committed in the absence of a conflict, was perpetrated against the victim(s) concerned because of the conflict at issue.’[68] In the Musema case, the ICTR was even more explicit on the need for a nexus between the accused’s acts and the hostilities, for the purposes of finding a civilian criminally responsible for a war crime: ‘?offences must be closely related to the hostilities or committed in conjunction with the armed conflict to constitute serious violations of Common Article 3 and Additional Protocol II. In other words, there must be a nexus between the offences and the armed conflict.’[69] In Rutaganda, the ICTR Trial Chamber followed Musema.[70] ‘[T]he evidence adduced in support of the charges against the accused must satisfy the Chamber that such a nexus exists. Thus, the burden rests on the Prosecutor to prove beyond a reasonable doubt that, on the basis of the facts, such a nexus exists between the crime committed and the armed conflict.’[71]
Obviously, being criminal courts, the ad hoc International Criminal Tribunals have addressed the question of the relationship between an individual civilian and the armed conflict for the purposes of determining criminal liability of a civilian, and there has been no substantive discussion of the question of direct participation in abstracto. It is not altogether clear whether the same requirements apply merely for the purposes of determining whether a civilian has unlawfully participated in hostilities, short of criminal liability, although it is not unreasonable to surmise that a similar conclusion would be reached in determining whether certain acts constitute direct participation (short of criminal behaviour).
3.2.6  In order to directly participate, does the civilian have to be a member of or have a link with a party to the conflict?

The question has arisen whether, in addition to the nexus requirement to the conflict, there is a further requirement that the civilian is a member of a party to the conflict or has some other type of link with a party to the conflict. This issue has also received considerable attention in Tribunal case law, although again for the purposes of finding criminal liability. A review of the relevant jurisprudence leads to the conclusion that it is not necessary for there to be a link between the acts committed and a party to the conflict, at least for the purposes of finding criminal liability for acts committed.
Until the recent decision of the Appeals Chamber in Akayesu?which appeared to settle the matter?there was some divergence in the jurisprudence of ICTY and ICTR Trial Chambers on this question.
In the Kunarac case, the ICTY Trial Chamber touched briefly on the question of the need for a link between an accused’s acts and a party to the conflict. Setting out the list of requirements identified in Čelebići,[72] it stated: ‘It would appear to the Trial Chamber that common Article 3 may also require some relationship to exist between a perpetrator and a party to the conflict.’[73] However, a determination on this question was not necessary in this case, as all of the accused fought on behalf of parties to the conflict.
In the decision of the Trial Chamber in Akayesu, the ICTR iterated that both the Tokyo trials and other post-World War II trials ‘unequivocally support the imposition of individual criminal liability for war crimes on civilians where they have a link or connection with a Party to the conflict’.[74] As to what type and degree of connection or link is required, the Chamber stated that:
‘For Akayesu [technically, a civilian] to be held criminally responsible under Article 4 of the Statute, it is incumbent on the Prosecutor to prove beyond a reasonable doubt that Akayesu acted for either the Government or the RPF in the execution of their respective conflict objectives. ? This implies that Akayesu would incur individual criminal responsibility for his acts if it were proven that by virtue of his authority, he is either responsible for the outbreak of, or is otherwise directly engaged in the conduct of hostilities. Hence, the Prosecutor will have to demonstrate to the Chamber and prove that Akayesu was either a member of the armed forces under the military command of either   of the belligerent parties, or that he was legitimately mandated and expected, as a public official or agent or person otherwise holding public authority or de facto representing the Government, to fulfil or support the war efforts.’[75]
In Kayishema and Ruzindana, the Chamber also required a link between the accused and the armed forces. It stated: ‘If individuals do not belong to the armed forces, they could bear the criminal responsibility only when there is a link between them and the armed forces.’[76]
This requirement of a link between the accused’s acts and the armed forces was reversed in the decision of the Appeals Chamber decision in Akayesu, where the Chamber found that ‘there is no explicit provision in the [ICTR] Statute that individual criminal responsibility is restricted to a particular class of people’.[77] ‘? it does not follow that the perpetrators of a violation of Article 3 must of necessity have a specific link with one of the above-mentioned Parties.’[78] It found that the decision of the ICTY in Kunarac had no support in either statute or case law. On the other hand, the Appeals Chamber upheld the need for a link between the violations and an armed conflict.[79]
It is submitted that this reasoning is equally valid for a finding of direct participation short of the commission of any additional criminal act, that is, a link to a party to the conflict or membership of an armed group is not a necessary element of direct participation, once a link to an armed conflict is proven.

The most serious consequence of taking a direct part in hostilities has already been alluded to: the civilian loses his or her protected status and may be attacked, for the duration of his or her participation, however long that is determined to be.
Anyone who takes part in hostilities, be they a combatant or a civilian, if captured, may be detained until the end of hostilities. Only the applicable legal regime will differ, with combatants POW status under the Third Geneva Convention of 1949 and Additional Protocol I, and civilians falling under the Fourth Convention.
Since for combatants, participation in hostilities is not per se illegal, while they may be detained upon capture they should not be punished merely for the fact of their (lawful) participation. Conversely, civilians, not being permitted to directly participate in combat, may be tried and punished for the fact of their unlawful participation alone, as such activity constitutes a war crime under the national law of most states.[80] Of course, they may also be tried and published for any additional war crimes they may have committed during the time of their unlawful participation.
Anyone who has participated in hostilities enjoys the benefit of the doubt as regards their status. Article 45(1) of Additional Protocol I provides:
‘1. A person who takes part in hostilities and falls into the power of an adverse Party shall be presumed to be a prisoner of war, and therefore shall be protected by the Third Convention, if he claims the status of prisoner of war, or if he appears to be entitled to such status, or if the Party on which he depends claims such status on his behalf by notification to the detaining Power or to the Protecting Power. Should any doubt arise as to whether any such person is entitled to the status of prisoner of war, he shall continue to have such status and, therefore, to be protected by the Third Convention and this Protocol until such time as his status has been determined by a competent tribunal.’
Once his status has actually been determined by a competent tribunal, pursuant to Article 5 of the Third Convention, and he has been found not to be a POW, he can be held as a regular detainee and, importantly, is not devoid of rights. Nor does he cease to be a protected person under Article 4 of the Fourth Convention. Still, parties have a certain discretion regarding the treatment of detained civilians who have unlawfully participated in hostilities. According to Article 5 of the Fourth Convention:
‘Where, in the territory of a Party to the conflict, the latter is satisfied that an individual protected person is definitely suspected of or engaged in activities hostile to the security of the State, such individual person shall not be entitled to claim such rights and privileges under the present Convention as would, if exercised in the favour of such individual person, be prejudicial to the security of such State. . . . In each case, such persons shall nevertheless be treated with humanity, and in case of trial, shall not be deprived of the rights of fair and regular trial prescribed by the present Convention. They shall also be granted the full rights and privileges of a protected person under the present Convention at the earliest date consistent with the security of the State or Occupying Power, as the case may be.’
Where civilians who have directly participated in hostilities are not considered to pose a security risk, the states could grant them all the rights and privileges of protected persons who are detained. These rights and protected are set out in detail in Section IV ? Regulations for the treatment of internees ? of the Fourth Convention.
Article 45(3) of the Third Convention provides: ‘Any person who has taken part in hostilities, who is not entitled to prisoner-of-war status and who does not benefit from more favourable treatment in accordance with the Fourth Convention shall have the right at all times to the protection of Article 75 of this Protocol.’[81] In occupied territory, any such person, unless he is held as a spy, shall also be entitled, notwithstanding Article 5 of the Fourth Convention, to his rights of communication under that Convention.
As the law applicable during non-international armed conflicts does not recognize the concept of combatancy, it does not explicitly recognize any minimum standards of treatment for detainees who have directed participated in hostilities.
The minimum standards recognized in common Article 3 of the Fourth Geneva Convention apply specifically to ‘[p]ersons taking no active part in the hostilities’. Similarly, the minimum standards of protection recognized for civilians in Additional Protocol II (in Articles 4 and 13) are specifically applicable only to persons ‘who do not take a direct part or who have ceased to take part in hostilities’ (Article 4). Under the law of most states, unlawful combatants will be treated as common criminals, or worse, as treasonous ? a capital offense in some countries.
This does not mean, of course, that these persons benefit from no minimum standards of treatment in detention. Like any detainees, they would benefit from the non-derogable universal and regional human rights norms that continue to exist even during armed conflicts.

The foregoing discussion has sought to identify some of the legal issues arising from the troubling increase in civilian participation in hostilities. The most obvious first conclusion is that more research into this fairly opaque area of the law is urgently needed. Such efforts are now being undertaken by various bodies and individuals, but more is surely needed. Clearly, the investigation and the discussions cannot be purely academic, given that the phenomenon of unlawful civilian participation in hostilities has serious operational consequences. The close involvement of the military in these efforts is to be welcomed and further encouraged.
From the cursory examination conducted here, it seems that amongst the most crucial questions to resolve are the mental element (what is required?), the temporal aspect, the burden of proof, and the military and law enforcement purposes sought to be achieved or advanced through clarification of the notion of direct participation.
Regarding the nexus to an armed group, the ICTY and ICTR have indicated that membership of an armed group is not necessary in order to find a civilian criminally liable for a war crime but even if a link to a party is not an absolute requirement for a finding of direct participation in hostilities, it could be one element indicating the objective intention to participate unlawfully.
While efforts must be made to pinpoint the modalities of civilian participation in hostilities, so that the law can keep pace with the realities on the ground, the ultimate aim must surely be not to produce an exhaustive list of the varying modes of civilian participation in hostilities (an impossible and futile exercise) but to try and identify criteria or common elements of participation which can be applied across the board, and in both international and non-international armed conflicts. These elements will have both physical (actus reus) and mental (mens rea) aspects. Whatever result is ultimately achieved, be it an elements-based or a definitional approach?must be able to take account not only of those forms of civilian participation currently manifest but those which are likely to present themselves in the future, including in the types of conflicts that are not yet recognized by international humanitarian law but which may eventually come to fall under its umbrella.
Underpinning and propelling forward all these efforts must be a concern with supporting and strengthening the fundamental goals of international humanitarian law, in particular, its core customary principles of distinction and protection. While it is undoubtedly true that unlawful civilian participation in hostilities weakens the principles of distinction and protection?and often deliberately so?the response of states to these challenges must not be to weaken these bulwarks against anarchy further still. If states do not show leadership in taking the legal and moral high ground in approaching the challenge of unlawful civilian participation in hostilities, the law will be rendered an empty shell, and increased suffering of innocents will be the inevitable result.

[1] This is a background working paper for a presentation by the author in April 2004 at the University of Teheran at a Round Table co-hosted by the University of Teheran and the Harvard University’s Humanitarian Law Research Initiative on the Interplay Between International Humanitarian Law and International Human Rights Law. The author thanks the organizers of the event, in particular, Professors Nasrin Mousaffa and Djamchid Momtaz of the University of Teheran and Mr Claude Bauderlaine and Ms Margaret Kowalsky of Harvard University.
[2] Article 48 of Additional Protocol I (Basic Rule) provides: ‘In order to ensure respect for and protection of the civilian population and civilian objects, the Parties to the conflict shall at all times distinguish between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objectives.’
[3] It was considered that to recognize combatant status for rebels would be to grant them legitimacy, a bridge too far for most states represented at the Diplomatic Conference.
[4] These are terms of art rather than terms with a precise and conventionally defined legal meaning. See R.R. Baxter, ‘So-called ‘Unprivileged Belligerency’: Spies, Guerrilla, and Saboteurs’, 28 BYIL (1951) pp. 323 at 328 where he states that ‘unprivileged belligerents’ are: ‘A category of persons who are not entitled to treatment either as peaceful civilians or as prisoners of war by reason of the fact that they have engaged in hostile conduct without meeting the qualifications established by Article 4 of the Geneva Prisoners of War Convention of 1949 . . .’ According to Watkins: ‘An unprivileged belligerent is a civilian (ie. A person not having combatant status) who takes part in hostilities thereby committing a belligerent act and having neither the protection from attack associated with civilian status nor qualifying for the privilege of being a prisoner of war.’ Colonel K.W. Watkin, ‘ Combatants, Unprivileged Belligerents and Conflicts in the 21st Century’, Background Paper prepared for the Informal High-Level Expert Meeting on the Reaffirmation and Development of International Humanitarian Law, Cambridge, June 27-29, 2002, pp. 4-5.
[5] Although Article 6(5) of Protocol II urges states at the end of the non-international armed conflict to grant the broadest possible amnesty to persons who have merely participated in the armed conflict (that is, excluding those who have committed crimes related to the conflict, namely, war crimes).
[6] The International Committee of the Red Cross and the TMC Asser Institute for International Law are co-organising a series of high-level expert meetings in The Hague, in an effort to shed more light on the subject of direct participation in hostilities. The first Joint Expert Meeting took place in June 2003; the second meeting on 25 and 26 October 2004; and a third meeting is planned for 2005.
[7] W. Fenrick, ‘The Law Applicable to Targeting and Proportionality after Operation Allied Force: A View from the Outside’, 3 Yearbook of International Humanitarian Law (2003) pp. 53 at 66.
[8] Declaration Renouncing the Use, in Time of War, of Explosive Projectiles Under 400 Grammes Weight, Reprinted in A. Roberts and R. Guelff, Documents on the Laws of War, 2nd edn. (Oxford, Clarendon Press 1989) pp. 30-31.
[9] See Watkin, loc. cit.  n. 4, p. 3.
[10] Regulations Respecting the Laws and Customs of War on Land, Annex to the 1907 Hague Convention IV Respecting the Laws and Customs of War on Land, Reprinted in Roberts and Guelff, op. cit. n. 8, pp. 48 at 53.
[11] Article 19 of the Fourth Convention provides: ‘The protection to which civilian hospitals are entitled shall not cease unless they are used to commit, outside their humanitarian duties, acts harmful to the enemy. Protection may, however, cease only after due warning has been given, naming, in all appropriate cases, a reasonable time limit, and after such warning has remained unheeded.’
[12] Article 33 of the Fourth Convention provides: ‘No protected person may be punished for an offence he or she has not personally committed. Collective penalties and likewise all measures of intimidation or of terrorism are prohibited.
Pillage is prohibited.
Reprisals against protected persons and their property are prohibited.’
[13] Article 49(4) of Additional Protocol I provides: ‘The provisions of this Section [i.e., Section I, General Protection against the Effects of Hostilities, of Part IV of the Additional Protocol] are additional to the rules concerning humanitarian protection contained in the Fourth Convention, particularly in Part II thereof, and in other international agreements binding upon the High Contracting Parties, as well as to other rules of international law relating to the protection of civilians and civilian objects on land, at sea or in the air against the effects of hostilities.’
[14] Supra n. 2.
[15] Article 51 provides: ‘1. The civilian population and individual civilians shall enjoy general protection against dangers arising from military operations. To give effect to this protection, the following rules, which are additional to other applicable rules of international law, shall be observed in all circumstances.
2. The civilian population as such, as well as individual civilians, shall not be the object of attack. Acts or threats of violence the primary purpose of which is to spread terror among the civilian population are prohibited.
3. Civilians shall enjoy the protection afforded by this Section, unless and for such time as they take a direct part in hostilities.
4. Indiscriminate attacks are prohibited. Indiscriminate attacks are:
(a)  Those which are not directed at a specific military objective;
(b)  Those which employ a method or means of combat which cannot be directed at a specific military objective; or
(c)  Those which employ a method or means of combat the effects of which cannot be limited as required by this Protocol; and consequently, in each such case, are of a nature to strike military objectives and civilians or civilian objects without distinction.
5. Among others, the following types of attacks are to be considered as indiscriminate:
(a)  An attack by bombardment by any methods or means which treats as a single military objective a number of clearly separated and distinct military objectives located in a city, town, village or other area containing a similar concentration of civilians or civilian objects; and
(b)  An attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated.
6. Attacks against the civilian population or civilians by way of reprisals are prohibited.
7. The presence or movements of the civilian population or individual civilians shall not be used to render certain points or areas immune from military operations, in particular in attempts to shield military objectives from attacks or to shield, favour or impede military operations. The Parties to the conflict shall not direct the movement of the civilian population or individual civilians in order to attempt to shield military objectives from attacks or to shield military operations.
8. Any violation of these prohibitions shall not release the Parties to the conflict from their legal obligations with respect to the civilian population and civilians, including the obligation to take the precautionary measures provided for in Article 57.’
[16] Article 52 provides: ‘1. Civilian objects shall not be the object of attack or of reprisals. Civilian objects are all objects which are not military objectives as defined in paragraph 2.

2. Attacks shall be limited strictly to military objectives. In so far as objects are concerned, military objectives are limited to 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.
3. 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.’
[17] Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion of 8 July 1996, para. 79.
[18] However, in the Čelebići case, a Trial Chamber of the International Criminal Tribunal for the Former Yugoslavia (ICTY) found that civilians can be considered as protected persons under Article 4 despite having the same nationality as the power in whose hand they find themselves. Applying the Nottebohm test, as applied by the International Court of Justice in the case of Liechtenstein v. Guatemala, ICJ Reps. (1955) pp. 4 at 23, the ICTY stated that ‘the International Tribunal may choose to refuse to recognize (or give effect to) a State’s grant of its nationality to individuals for the purposes of applying international law’. The Chamber emphasised ‘the necessity of considering the requirements of article 4 of the Fourth Geneva Convention in a more flexible manner. The provisions of domestic legislation of citizenship in a situation of violent State succession cannot be determinative of the protected status of persons caught up in conflicts which ensue from such events.’ Prosecutor v. Zejnil Delalić, Zdravko Mucić also known as “Pavo”, Hazim Delić, and Esad Land?o also known as “Zenga”, Case No. IT-96-21-T, Judgement, 16 November 1998, para. 263.
[19] Set out in Article 1 of the Hague Regulations: ‘1. To be commanded by a person responsible for his subordinates; 2. To have a fixed distinctive emblem recognizable at a distance; 3. To carry arms openly; and 4. To conduct their operations in accordance with the laws and customs of war.’ Regulations Respecting the Laws and Customs of Land, Annex to 1907 Hague Convention IV Respecting the Laws and Customs of War on Land, Reprinted in Roberts and Guelff, op. cit. n. 8, pp. 44 at 48.
[20] A.R. Thomas and J.C. Duncan, eds., Annotated Supplement to The Commander’s Handbook on the Law of Naval Operations, 73 International Law Studies (1999) pp. 296-297.
[21] Watkin, loc. cit. p. 4.
[22] Article 2 of the 1907 Hague Regulations Respecting the Law and Customs of War on Land provides that: ‘The inhabitants of a territory which has not been occupied, who, on the approach of the enemy, spontaneously take up arms to resist the invading troops without having had time to organize themselves in accordance with Article 1 [the qualification of belligerents], shall be regarded as belligerents if they carry arms openly and if they respect the laws and customs of war.’
[23] The views of the Prussian military strategist, Karl von Clausewitz, are set out in his classical work, On Warfare (London, Penguin Classics 1982).  He is most famous for his view that war is the continuation of politics by other means.
[24] For a discussion of some of the new manifestations of conflict see H. Münkler, ‘The Wars of the 21st Century’, 85 International Review of the Red Cross (2003) p. 7.
[25] For a cogent analysis of the changing nature of war away Clausewitz’s Trinitarian model, see M. Van Creveld, The Transformation of War (New York, The Free Press 1991).
[26] For a good general overview see M.E. Guillory, ‘Civilianizing the Force: Is the United States Crossing the Rubicon?’ 51 Air Force Law Review (2001) p. 11.
[27] US Department of the Army Pamphlet 690-47, Civilian Personnel, DA Civilian Employee Deployment Guide, Headquarters of the Army, 1 November 1995.
[28] Rand Research Brief 7520 (1998): Can Civilianization Save on Costs?’
[29] S.M. Gates and A.A. Robbert, Comparing the Costs of DoD Military and Civil Service Personnel, RAND National Defense Research Institute, MR-980-OSD, 1998.
[30] See on this point M.N. Schmitt, ‘Direct Participation in Hostilities and 21st Century Armed Conflict’, Festscrift for Dieter Fleck (forthcoming 2004), pp. 501 at 509. (Thanks to the author for providing an advance copy.)
[31] See Department of the Army, Pamphlet 690-47, DA Civilian Employee Deployment Guide (1 November 1995); Department of the Air Force, Instruction 36-801, Personnel, Uniforms for Civilian Employees (29 April 1994).
[32] Supra n. 27.
[33] T.E. Ricks, ‘The widening gap between the military and society’, The Atlantic Monthly, July 1997.
[34] A. Markusen, ‘The Case Against Privatizing National Security’, Paper dated 24 September 1999 prepared for discussion at the Study Group on the Arms Trade and the Transnationalization of the Defense Industry, Council on Foreign Relations, New York, 1 October 1999.
[35] Article 51(2) Additional Protocol I provides: ‘? Acts or threats of violence the primary purpose of which is to spread terror among the civilian population are prohibited.’ Article 4(2)(d) of Additional Protocol II prohibits ‘[a]cts of terrorism’.
[36] See S.M. Hersh, ‘Manhunt: The Bush administration’s new strategy in the war against terrorism’, The New Yorker, 23 and 30 December 2002.
[37] P. Verri, Dictionary of the International Law of Armed Conflict (Geneva, ICRC 1992) p. 57.
[38] Commentary on the Additional Protocols of 8 June 1977 to the Geneva Conventions of 12 August 1949, Y. Sandoz, C. Swinarki and B. Zimmerman, eds. (Geneva, ICRC/Martinus Nijhoff 1987) (Geneva, ICRC 1987) para. 1943, pp. 618-619.
[39] Ibid., para. 1942, p. 618.
[40] Prosecutor v. Milorad Krnojelac, Case No. IT-97-25, 15 March 2002, para. 54.
[41] Y. Dinstein, The Conduct of Hostilities Under the Law of International Armed Conflict (Cambridge, Cambridge University Press 2004) p. 152.
[42] Ibid., p . 152.
[43] Prosecutor v. Jean-Paul Akayesu, Case No. ICTR-96-4-T, 2 September 1998, para. 629.
[44] Commentary, op. cit. n. 40, op. cit., para. 1679.
[45] Ibid., para. 4787.
[46] See F. Kalshoven and L. Zegveld, Constraints on the Waging of War (Geneva, ICRC March 2001) p. 99.
[47] U.S. Navy/Marine Corps/Coast Guard, The Commander’s Handbook on the Law of Naval Operations (NWP 1-14M, MCWP  P5800.7, para. 11.3 (1995).
[48] A.P.V. Roger, Law on the Battlefield (Manchester, Manchester University Press 1996) p. 8.
[49] US Executive Order 12333 and Assassination, Memorandum prepared by the Chief of the International Law Branch, Office of the Judge Advocate General, Department of the Army, 2 November 1989.
[50] See Schmitt, loc. cit. n. 30, pp. 501 at 505.
[51] Ibid., at p. 525.
[52] Commentary, op. cit. n. 38, para. 1942.
[53] It should be noted that the fact of a civilian being armed in a zone of hostilities should not of itself be sufficient to transform a peaceful civilian into a direct participant in hostilities. The weapon could be carried for various legitimate reasons, including personal self-defense. It would at least be necessary for the weapon to be used, with hostile intent, against an enemy combatant or military objective in order for the civilian to be considered as a direct participant.
[54] Dinstein, op. cit. n. 41, pp. 27-28.
[55] Roger, op. cit. n. 48, p. 7.
[56] Kalshoven and Zegveld, op. cit. n. 46, p. 129.
[57] Dinstein, op. cit. n. 41, pp. 27-28.
[58] U.S. Air Force Commander’s Handbook (1980) paras. 2-8.
[59] F.M3-100.21, 3 January 2003.
[60] Schmitt, loc. cit., n. 30, p. 505.
[61] ‘During the course of the discussions on Additional Protocol I, several delegations indicated that the expression “hostilities” used in this article included preparations for combat and the return from combat. Similar problems arose in Article 44 (Combatants and prisoners of war) with regard to the expression “military deployment preceding the launching of an attack.’ Commentary, op. cit. n. 38.
[62] See Kalshoven and Zegveld, op. cit. n. 46, p. 99.
[63] Commentary, op. cit. n. 38, para. 4789.
[64] The Israeli Defence Forces, relying on a self-defense argument, would argue that they are acting as a matter of necessity, given that there is, in their view, no other?or more effective?way to neutralize the terrorist threat.
[65] Schmitt, loc. cit. n. 30, p. 506.
[66] Prosecutor v. Dusko Tadic a/k/a “Dule”, Case No. IT-94-1-T, Opinion and Judgment, 7 May 1997, para. 207.
[67] Ibid., para. 573.
[68] The Prosecutor v. Zlatko Aleksovski, Case No. IT-95-14/1-T, Judgement, 25 June 1999, para. 45.
[69] The Prosecutor v. Alfred Musema, Case No. ICTR-96-13-T, Judgement and Sentence, 27 January 2000, para. 973. See also paras. 259-262.
[70] The Prosecutor v. Georges Anderson Nderubumwe Rutaganda, Case No. ICTR-96-3-T, Judgement and Sentence, 6 December 1999, para. 104.
[71] Ibid., para. 105.
[72] Supra n. 18.
[73] Prosecutor v. Dragoljub Kunarac, Radomir Kovač and Zoran Vuković, Case No. IT-96-23-T&IT-96-23/1-T, Judgement, 22 February 2001, para. 407.
[74] Akayesu Trial Judgement, supra n. 43, para. 633. Emphasis added.
[75] Ibid., para. 640.
[76] The Prosecutor v. Clement Kayishema and Obed Ruzindana, Case No. ICTR-95-1-T, Judgement, 21 May 1999, para. 175.
[77] The Prosecutor v. Jean-Paul Akayesu, Case No. ICTR-96-4-A, Judgement, 1 June 2001, para. 436.
[78] Ibid., para. 437.
[79] Ibid., para. 444.
[80] See Kalshoven and Zegveld, op. cit. n. 46, p. 99.
[81] Article 75 of Additional Protocol I sets out a series of fundamental guarantees or minimum standards that must be observed in relation to all persons who have fallen into the hands of the enemy and who do not benefit from more favourable treatment, including protection against violations to their physical integrity and minimum standards of due process in case of trial.