2. The Principles of Humanity and Military Necessity

The core of the ICRC's argument that the contemporary law of armed conflict imposes restraints as envisaged in Section IX of the ICRC Guidance rests on the principles of military necessity and humanity. According to the ICRC Guidance,Footnote ¹⁰

The Commentary to Section IX of the ICRC Guidance (‘Commentary’) subsequently recounts the meanings of military necessity and humanity that are well known from certain national manuals. Accordingly, military necessity, on the one hand, permits

Humanity, on the other hand, forbids ‘the infliction of suffering, injury or destruction not actually necessary for accomplishment of legitimate military purposes’.Footnote ¹² According to the Commentary, humanity complements military necessity and is implicit in it.

The Commentary continues:Footnote ¹³

In the following paragraphs, the Commentary insists that what is being suggested is not an inflexible standard, but one that can only be applied contextually, taking due account of the circumstances in which the use of lethal force is being contemplated:Footnote ¹⁴

It is in this latter context that reference is made to the 2006 judgment of the Israeli High Court of Justice in Public Committee Against Torture.Footnote ¹⁵ In particular, the Commentary considers that the following passage of the judgment supports its position:Footnote ¹⁶

The Commentary subsequently illustrates how the suggested restraints would play out in a number of scenarios, including the situation in which a military commander of an organised armed group visits relatives in government-controlled territory.

The foregoing reasoning then leads the ICRC to draw the following conclusion:Footnote ¹⁷

Let us then turn to a scrutiny of the aforementioned line of argument that considers military necessity and humanity as providing a basis for Section IX. A first observation concerns the starting point of the reasoning – namely that the law of armed conflict in general, and the notions of humanity and military necessity in particular – provide for restraints that are not expressly stipulated. Before examining the precise way in which this argument is constructed, the fundamental point here is whether one approaches the law of armed conflict on the conduct of hostilities in its entirety as one that provides restraints on what parties to an armed conflict may do, but leaves everything that is not expressly regulated to the discretion of those parties; or whether the law of armed conflict starts from the opposite assumption that parties are prohibited from doing anything that is not expressly permitted under the legal principles and rules that derive from a positive source of international law. Surely, there are valid arguments on either side of that debate – a debate that is an inherent structural feature of international legal argument and not limited to the law of armed conflict.Footnote ¹⁸

It is submitted, however, that the grammar of the law of armed conflict relating to the conduct of hostilities is more in line with the first approach. Couched as they are in terms of prohibitions, the overwhelming majority of the rules and principles in the area of conduct of hostilities suggest that actions that are not prohibited are permissible.Footnote ¹⁹ Surely, the opening question of who and what is targetable does not follow that logic, since everything and everyone not expressly allowed to be targeted is protected from direct attack. However, the law reverses that logic in answering the subsequent question as to how such military objectives can be engaged. The law allows them to be engaged by all methods and means of warfare except those outlawed by the principles and rules of the law of armed conflict, such as those of a nature to cause superfluous injury and unnecessary suffering, those that are indiscriminate or those that are intended or may be expected to cause widespread, long-term and severe damage to the natural environment. This is one – although not the only – important structural difference from international human rights law, which by and large follows the logic of states being prohibited from restricting human rights unless permitted to do so. To approach the law on the conduct of hostilities from the opposite permissive starting point – that parties to an armed conflict are allowed to use those methods and means which are not expressly prohibited – is more in tune with the nature of the law of armed conflict as a law that governs a state of exception rather than normality. Hence, there are good reasons for maintaining that, in the area of the law governing the conduct of hostilities, any restriction on what parties to an armed conflict may do when using force against military objectives in their quest to overcome the adversary must derive from an express restriction stipulated in a rule or principle of positive international law.

For this reason, it appears doubtful that the reference in the Martens Clause to the principles of humanity and dictates of public conscience can function as an independent basis for the restraints asserted in Section IX. The normative content and legal force of the Martens Clause have sparked debate, a detailed discussion of which is beyond the purview of this article.Footnote ²⁰ However, an expansive interpretation to the effect that the Martens Clause reference to principles of humanity and dictates of public conscience provides restraints on the action of parties to an armed conflict, even though a given course of conduct is not explicitly prohibited by a rule of positive international law, is neither borne out by state practice that could establish an agreement between states on such an interpretation,Footnote ²¹ nor can one deduce such an understanding from the case law of international courts and tribunals.Footnote ²² It is therefore submitted that as long as, and to the extent that, the principles of humanity and dictates of public conscience mentioned in the Martens Clause have not found their expression in a treaty provision, a rule of customary international law, or other source of positive international law, they do not provide a basis for the restraints contemplated in Section IX. Principles of humanity and dictates of public conscience may be driving forces for the development of the law, but they do not constitute the law.

Proceeding from the same premise that any restraint on the use of force in situations of armed conflict must derive from a positive rule of international law, the next question that arises is whether, and to what extent, humanity and military necessity possess that pedigree. In all fairness to the ICRC Guidance it is not suggested in the Commentary that humanity and military necessity operate as such positive rules of international law. Rather, in the ICRC's view, they ‘constitute guiding principles for the interpretation of the rights and duties of belligerents’.Footnote ²³ However, before we turn to a critique of this latter argument, it is crucial to understand the status, or lack thereof, of the two notions of humanity and military necessity as positive rules of international law. It is widely recognised that the two underlying considerations lack that quality. They do not constitute legal principles or rules. Rather, the law of armed conflict as a whole rests on the balance that states at a given point in time have struck between the two considerations.Footnote ²⁴ Each and every legal rule and principle of the law of armed conflict therefore manifests and incorporates that balance. The two notions are ‘within the law’,Footnote ²⁵ and they are so wholly and solely.

The foregoing should not be misunderstood to mean that the law does not contain openings for consideration of military necessity in manifold ways. The common clauses such as ‘unless circumstances do not permit’Footnote ²⁶ and exceptions to certain prohibitions on account of ‘military necessity’Footnote ²⁷ are examples. However, military necessity and humanity do not operate as independent legal norms in and of themselves. In other words, if the law is silent on a given issue, neither humanity nor military necessity can directly, and on its own force alone, provide an answer to the underlying question. If the law is permitting a given action, such as the use of force against a combatant or a fighter, considerations of humanity do not provide for further legal restraints on the use of that force, nor does the restrictive dimension of military necessity.Footnote ²⁸ As a corollary, and at least equally importantly, the permissive dimension of military necessity does not allow for more than that which the positive rules of the law of armed conflict permit. If, for instance, the use of a given weapon is prohibited, such as poison, military necessity does not function as an independent legal standard on the basis of which that prohibition can be modified or overridden. To make the case for a different understanding of how considerations of humanity and military necessity operate in the realm of the law of armed conflict would have serious consequences. It would not only allow superimposing humanitarian requirements where the positive legal rules and principles of the law of armed conflict are permissive. Rather, it would also lead to a reintroduction of military necessity that allows for military actions that are otherwise prohibited. In the final analysis, to view the two fundamental principles of humanity and military necessity as not being fully incorporated into the law of armed conflict may hence lead to a reintroduction of concepts that strongly resemble the doctrine of Kriegsraison.Footnote ²⁹

It is with the preceding considerations in mind that we can now turn to the assertion in the ICRC Guidance that Section IX finds its legal basis in the rights and duties of belligerents as stipulated in the law of armed conflict if and when such rights and duties are interpreted in light of the ‘guiding principles’ of military necessity and humanity. The suggestion in the Guidance is that military necessity and humanity informs the interpretation of rules of the law of armed conflict in such a way that restraints are being imposed that the original rule does not stipulate. The silence on the amount of force that is permissible in engaging a civilian that has lost his or her protection from direct attack on account of directly participating in hostilities is being filled by reference to military necessity and humanity. In fact, the substance of the rule on loss of protection is changed from ‘civilians who take a direct part in hostilities lose their protection from direct attack for such time’ to ‘civilians who take a direct part in hostilities lose their protection from direct attack for such time, provided that such a direct attack is militarily necessary’. It may be readily apparent from the preceding analysis that such an outcome is in substance no different from elevating the two notions of humanity and military necessity to independent normative standards that possess legal force in and of themselves, rather than being fully accommodated within the positive provisions of the law of armed conflict.

What is more, there is no apparent reason why the argument advanced by the ICRC Guidance should be limited to the use of force against civilians who are directly participating in hostilities. The purported restraints flowing from the principle of military necessity would be equally applicable to other persons who constitute legitimate targets – namely, combatants and fighters in non-international armed conflicts. If one were to take the reasoning of the Guidance underlying Section IX to its logical conclusion, it would mean, for instance, that combatants who sleep in their barracks or retreat may not be targeted with lethal force if there are less harmful means available. However, these are classic examples of instances in which states have considered the use of lethal force to be lawful.Footnote ³⁰ As long as the use of such force is compliant with the restraints that emanate from the law governing the conduct of hostilities (including proportionality, precautions, denial of quarter, and weapons restrictions), parties to an armed conflict are entitled to put enemy combatants hors de combat, be it through capturing, injuring or indeed killing them. To posit otherwise would require a radical shift in the practice of states and their legal conviction that the use of lethal force against persons who do not enjoy protection from direct attack is always lawful in situations of armed conflict, within the above-mentioned legal parameters of proportionality, precautions, denial of quarter, and weapons restrictions.

At least equally important is that nothing in the reasoning underlying Section IX suggests that such an interpretive function of the notion of military necessity should be limited to the restrictive dimension of military necessity. The question therefore arises as to what would stand in the way of interpreting an absolute prohibition in the law of armed conflict into one that can be modified by considerations of military necessity. It could then be argued, for instance, that the prohibition to use cultural objects in support of the military effort that is contained in the two 1977 Additional Protocols to the Geneva ConventionsFootnote ³¹ is a rule that prohibits such use only to the extent that it is not militarily necessary. Indeed, to accept such an interpretation would instil credence in the infamous statement of an ICTY Trial Chamber in the Blaškić case that ‘[t]argeting civilians or civilian property is an offence when not justified by military necessity’,Footnote ³² which was rightly reversed on appeal.Footnote ³³ In other words, one fails to see what prevents the reasoning of the ICRC to be used so that the permissive dimension of military necessity – the idea that the notion allows force and that such force is necessary to win the war – leads to an interpretation of a rule of the law of armed conflict in a way so as to allow more than that which is permitted under the original rule. It is readily apparent that such a result would not only undermine the humanitarian cause that the ICRC is pursuing in positing restraints on the use of force such as those envisaged in Section IX of its Guidance. It would, in the ultimate equation, open up the possibility that the law of armed conflict retrogresses towards something reminiscent of the doctrine of Kriegsraison with all its devastating effects.

In sum, much militates against construing the restraints contemplated in Section IX of the ICRC Guidance on the basis of the principles of humanity and military necessity.

3. The Prohibition of Employing Methods and Means of a Nature to Cause Superfluous Injury and Unnecessary Suffering

The second potential basis for Section IX of the ICRC Guidance is the prohibition of employing methods and means of a nature to cause superfluous injury and unnecessary suffering. Without doubt, that prohibition is a genuine legal principle of the law of armed conflict, firmly rooted in conventional and customary law.Footnote ³⁴ The ICRC's Guidance does not develop the principle as a possible basis for Section IX. Instead, it merely restates that the prohibition of employing methods and means of a nature to cause superfluous injury and unnecessary suffering is one of the limitations that the law imposes, in addition to which the restraints contemplated in Section IX operate. However, the prohibition was discussed on a number of occasions in the expert processFootnote ³⁵ and has also resurfaced in subsequent debatesFootnote ³⁶ about Section IX.

The construction of the prohibition as a basis for Section IX is largely inspired by the writings of Jean Pictet, who in the 1970s and 1980s asserted on a number of occasions: ‘If we can put a soldier out of action by capturing him, we should not wound him; if we can obtain the same result by wounding him, we must not kill him. If there are two means to achieve the same military advantage, we must choose the one which causes the lesser evil’.Footnote ³⁷

In support of the prohibition of employing methods and means of a nature to cause superfluous injury and unnecessary suffering as a basis for Section IX, reference is also at times made to the statement of the International Court of Justice (ICJ) in its Advisory Opinion on Nuclear Weapons.Footnote ³⁸ According to the Court, the prohibition does not only constitute an intransgressible principle of international customary law and a cardinal principle of the law of armed conflict, but it outlaws the infliction of ‘harm greater than that unavoidable to achieve legitimate military objectives’.Footnote ³⁹

If one examines the precise contours of the prohibition of employing methods and means of a nature to cause superfluous injury and unnecessary suffering,Footnote ⁴⁰ a conceivable argument for its providing the basis for Section IX would seem to be the following. The prohibition has been extended from covering weapons to apply also in the realm of methods of warfare in Article 35(2) of AP I, subsequent treaties and customary international law. ‘Methods’ are generally understood to mean the way in which weapons are used, such as tactics, strategies etc. Tactics and strategies which employ avoidable force against legitimate targets would violate the prohibition.Footnote ⁴¹

Such an argument would seem to be compatible with the ordinary meaning of the terms ‘methods of a nature to cause superfluous injury and unnecessary suffering’ if interpreted in good faith in their context and in the light of the object and purpose of the prohibition.Footnote ⁴² In fact, an interpretation along the lines suggested would instil meaning into a prohibition that is otherwise shrouded in mystery as far as ‘methods’ are concerned.Footnote ⁴³ However, one needs to acknowledge at the same time that there is no evidence that states share such an interpretation. There is no practice in the application of the prohibition of methods of warfare of a nature to cause superfluous injury and unnecessary suffering which establishes the agreementFootnote ⁴⁴ that it amounts to a ‘least harmful means’ requirement as contemplated in Section IX of the ICRC Guidance. Even the lone domestic judgment that suggests a restraint on the use of lethal force that closely resembles Section IX of the ICRC Guidance – the judgment of the Israeli High Court of Justice in Public Committee Against Torture Footnote ⁴⁵ – does not support such a construction of the prohibition. The Israeli High Court of Justice reached its conclusion on the basis of the principle of proportionality under domestic law and human rights law, rather than the prohibition of methods of warfare of a nature to cause superfluous injury and unnecessary suffering, or, for that matter, the law of armed conflict more generally. Indeed, the ICRC Study does not clarify the meaning of what constitute ‘methods of a nature to cause superfluous injury and unnecessary suffering’ and nothing in the collected material suggests that such an interpretation is accepted by states.Footnote ⁴⁶ Admittedly, there is nothing to prevent states from adopting such an interpretation in the future, but currently they do not interpret the prohibition of methods of warfare of a nature to cause superfluous injury and unnecessary suffering in a way so as to provide a legal basis for Section IX.

4. Human Rights Law

Let us then turn to the question of whether, and to what extent, human rights law could provide a legal basis for the restraints on the use of force contemplated in Section IX of the ICRC Guidance. To answer that question, one first has to consider the applicability of human rights law in times of armed conflict. Secondly, the relationship between human rights law and the law of armed conflict needs to be addressed.

As to the first question, human rights law applies, as a rule, in the territory of a state that is subject to the conventional or customary human rights norm in question, also in times of armed conflict. However, the existence of an armed conflict may bring with it certain exceptions to the general rule that a state is so bound. This may notably be the case, for instance, where a part of that state's territory is under the control of another state in the course of belligerent occupation, or under the control of an organised armed group in the course of a non-international armed conflict. In such a case of a lack of territorial control exercised by the state, the latter's human rights obligations may be temporarily inoperative.Footnote ⁴⁷

Under certain circumstances, human rights law also applies extraterritorially. This is specifically the case if and when the action of the state concerned is such that it renders the individual concerned, in the words of the International Covenant on Civil and Political Rights, ‘subject to its jurisdiction’.Footnote ⁴⁸ While a detailed analysis of the findings by human rights bodies on, and the academic debate about, the extra-territorial applicability of human rights would go beyond the purview of this article, considerable agreement exists that human rights law does apply in territory other than the state's own if and when it exercises effective control over territory or persons.Footnote ⁴⁹ Situations of belligerent occupation and extraterritorial detention are fairly widely, albeit not unanimously,Footnote ⁵⁰ accepted scenarios where the level of control reaches the required threshold of control,Footnote ⁵¹ whereas air operations are contested.Footnote ⁵²

States remain bound by human rights law also in times of armed conflict in the aforementioned cases, except to the extent that they may have properly exercised their right to take measures to derogate from certain human rights in times of public emergency which threatens the life of the nation.Footnote ⁵³ As a result, human rights law and the law of armed conflict may apply simultaneously during a situation of armed conflict.

In such a situation of simultaneous application, the question arises as to the relationship between human rights law and the law of armed conflict. This is especially pertinent where the two regimes differ, as is the case in relation to the use of lethal force, with which we are concerned in the present context. Here, human rights law is stricter than the law of armed conflict.

In order for a deprivation of life not be arbitrary and hence a violation of human rights, the use of lethal force must not only have a legal basis, but the amount of force used may not exceed that which is necessary to achieve a legitimate purpose – such as self-defence or the defence of others against an imminent threat of death or serious injury, or to prevent the perpetration of a particularly serious crime involving grave threat to life, to arrest a person presenting such a danger and resisting arrest, or to prevent his or her escape. Furthermore, the force must be proportionate to the actual danger that is being countered. Last but not least, reasonable measures need to be taken so as to minimise the amount of force used, such as a warning or giving the opportunity to surrender. Reasonable non-violent means need to be exhausted before resorting to the use of potentially lethal force.Footnote ⁵⁴ It follows from these requirements that human rights law clearly establishes a least harmful means requirement that bears considerable resemblance to that suggested in Section IX of the ICRC Guidance.

According to the law of armed conflict, on the other hand, our previous analysis suggests that no such requirement exists. Lethal force may be used against members of the armed forces of a party to an armed conflict and civilians who directly participate in hostilities, regardless of whether they could be captured or arrested.

In such a situation of conflict between a norm of human rights law on the one hand, and a norm of the law of armed conflict on the other, the question arises as to which norm prevails. According to the ICJ, the maxim lex specialis derogat legi generali resolves such an instance of a normative conflict with the more specific rule prevailing over the more general rule.Footnote ⁵⁵ In the words of the ICJ:Footnote ⁵⁶

This statement of the ICJ suggests a lex specialis between the regulation of the right to life according to the law of armed conflict in the area of the conduct of hostilities and the regulation of the right to life according to human rights law. In subsequent findings, however, the ICJ appears to have extended the lex specialis/lex generalis relation beyond the specific area of the conduct of hostilities in as much as it has asserted that, in situations of simultaneous application of human rights law and the law of armed conflict, ‘the Court will have to take into consideration both these branches of international law, namely human rights law and, as lex specialis, international humanitarian law’.Footnote ⁵⁷ The latter statement could be understood to mean that, in times of armed conflict, the rules of the law of armed conflict will at all times prevail over incompatible norms of human rights law. Such an understanding would be based on the general premise that the law of armed conflict is specifically devised to regulate situations of armed conflict.

However, it may very well be argued that the rule that the law of armed conflict functions in the aforementioned way as lex specialis to human rights law in times of armed conflict is not absolute. In certain areas, human rights law may supply the more specific standards even in such times. This is notably the case in situations that, while occurring during an armed conflict, closely resemble those for which human rights standards have been developed with a higher degree of specificity. Operations during an armed conflict that for all sense and purposes are law enforcement operations provide a pertinent example. Accordingly, it has been argued that the use of force in relatively calm situations of occupation for the purpose of maintaining public order and safety,Footnote ⁵⁸ or in areas under the firm control of state authorities in times of non-international armed conflict,Footnote ⁵⁹ should be governed by the legal parameters that human rights law (as the lex specialis) provides for the use of force. Indeed, between the clear outer extremes of situations that can be contemplated – between operations that constitute law enforcement operations that occur during situations of armed conflict on the one hand, and fully fledged, large-scale combat operations, on the other – some have suggested that the interplay between the law of armed conflict and human rights law leads to a gradation of the amount of force that can lawfully be used.Footnote ⁶⁰

Such a graded approach appears to find some support in the judgment of the Israeli High Court of Justice in Public Committee Against Torture,Footnote ⁶¹ in which the Court stated:Footnote ⁶²

It then contextualised that requirement in the following way:Footnote ⁶³

To construe the restraints on the use of force contemplated in Section IX of the ICRC Guidance on the basis of human rights law nevertheless raises a number of concerns.

First, on a conceptual level, to rely on human rights law would result in the creation of disparate regimes for the use of lethal force if and when non-state actors (organised armed groups) are parties to an armed conflict, which in turn would undermine one of the fundamental precepts of the law of armed conflict – namely the legal equality of belligerent partiesFootnote ⁶⁴ – as the applicability of human rights law to organised armed groups is at least debatable. While some evidence suggests that organised armed groups are gradually brought into the reach of international human rights law by virtue of a process of international customary law formation,Footnote ⁶⁵ the better view seems to remain that such evidence is insufficient for the time being to conclude that such a customary process has already reached the point of crystallising into a firm rule.Footnote ⁶⁶ If one accepts the latter view, the restraints in Section IX would be binding only upon states, but not on organised armed groups. Such inequality before the law may ultimately impact negatively on a party acting in conformity with its international legal obligations, as the reciprocal expectation of compliance by parties to an armed conflict remains one of the central motivating factors for compliance.

At the same time, it needs to be acknowledged that there may be more to the notion of equality of belligerent parties before the law than meets the eye. Any recognition that human rights law remains applicable in times of armed conflict and may supply the normative standard with which states must comply already creates a certain inequality in the legal obligations of states vis-à-vis organised armed groups. Indeed, the fundamental conceptual notion that parties to an armed conflict are equal before the law is genuine only to the law of armed conflict, not to other areas of law. The notion is certainly absent from domestic law, whereby members of non-state armed forces remain subject to criminal sanctions for the mere fact of having participated in hostilities, whereas state armed forces have a legal privilege under domestic law to do so. But the notion is equally not a feature of human rights law, which binds states but not individuals. Nevertheless, one needs to acknowledge that a construction of Section IX on the basis of human rights law would mean that only states are bound by the restraints that it purports exist, whereas non-state organised armed groups would be allowed to use force under the law of armed conflict without being subject to the same restraints.

Secondly, the construction of Section IX on the basis of human rights law encounters considerable difficulties in situations where force is used extraterritorially. The jurisprudence of the ICJ and of several human rights bodies – most notably the Human Rights Committee and the European Court of Human Rights – with the arguable exception of the Inter-American Commission on Human Rights,Footnote ⁶⁷ would mean that the extraterritorial applicability of human rights law would be excluded as a matter of principle, except in cases where the control of a state over foreign territory is effective enough to trigger the obligations of that state under the respective human rights treaty.Footnote ⁶⁸ Where that required level of control is not attained, there would therefore be no room for restraint on the use of force as contemplated in Section IX.

Thirdly, human rights are generally held to be indivisible and interdependent so that they apply either in their totality or not at all. A manifestation of such a holistic understanding of the applicability of human rights law is the European Court of Human Rights determination in the case of Banković that the obligation of a state to secure to everyone within its jurisdiction the rights and freedoms defined in Section I of the European Convention cannot be divided and tailored in accordance with the particular circumstances of the act in question.Footnote ⁶⁹ What the European Court thereby appeared to suggest is that if one right (in casu the right to life) is applicable, all the other rights enshrined in the European Convention equally apply, except in cases where a state has properly exercised its right to take measures to derogate from certain human rights in a time of public emergency which threatens the life of the nation. In contrast, the graded approach would call for more differentiation, in which the control exercised by a state may very well be sufficient to secure the right to life by effectuating an arrest instead of using lethal force, but insufficient to secure certain other rights, such as the right to marry and to found a family. Cases such as Banković and the human rights discourse in inter-governmental organisations that subscribes to the indivisibility and interdependence of human rights would therefore, proverbially speaking, throw out the baby with the bath water.

Ultimately, the holistic understanding of the applicability of human rights law militates against that body of law providing the legal basis for a graded approach along the lines suggested in Section IX of the ICRC Guidance. Whether human rights law moves away from such a holistic understanding remains to be seen. At least the more recent case law of the European Court of Human Rights seems to suggest that it might. In particular, in Al Skeini, the Court in an apparent diversion from its earlier findings in Banković, held thatFootnote ⁷⁰

However, at the present time, it seems premature to conclude from that case alone that human rights law has undergone a transformation that would allow for a graded approach to the use of lethal force along the lines suggested in Section IX of the ICRC Guidance.