International human rights law and international humanitarian law are traditionally two distinct branches of law, one dealing with the protection of persons from abusive power, the other with the conduct of parties to an armed conflict. Yet, developments in international and national jurisprudence and practice have led to the recognition that these two bodies of law not only share a common humanist ideal of dignity and integrity but overlap substantially in practice. The most frequent examples are situations of occupation or non-international armed conflicts where human rights law complements the protection provided by humanitarian law.

This article provides an overview of the historical developments that led to the increasing overlap between human rights law and humanitarian law. It then seeks to analyse the ways in which the interplay between human rights law and humanitarian law can work in practice. It argues that two main concepts inform their interaction: The first is complementarity between their norms in the sense that in most cases, especially for the protection of persons in the power of a party to the conflict, they mutually reinforce each other. The second is the principle of lex specialis in the cases of conflict between the norms.

From the adoption of the United Nations' Charter, the interplay between international human rights law and international humanitarian law has been subject to many questions to which scholars, judges and institutions still struggle to provide a clear answer. At present, there are a number of divergent stances on the parallel application of the disciplines, but they are generally elusive as to their exact methodology and supporting legal basis. This article argues that a well-coordinated application of international humanitarian law and international human rights law is vital to ensuring adequate protection during armed conflict and the effective implementation of the legal frameworks. It examines the articulation of the relationship between international humanitarian law and international human rights law through the lex specialis model. Considering the theory of lex specialis, this article questions the widely accepted view that this theoretical model, based on the specificity and generality of the law, can clarify the interplay and facilitate the co-application of international human rights law and international humanitarian law. In light of this, it is argued that a new means is needed to clarify the interplay between the disciplines. This article advocates the substitution of the lex specialis principle and development of a more specific methodology to resolve issues linked with the concurrent jurisdiction of the disciplines. It suggests that the theory of lex specialis yields to a different theoretical model based on multiple pre-determined criteria that balance the reality of conflict with the respect of humanity and protection of individuals.

The events of recent years have prompted a closer examination of the legal complexities arising from transnational armed conflicts pitting a state against a non-state organized armed group based outside the state's territory. For much of the Twentieth Century it remained unclear whether human rights law apply to a state's conduct during armed conflict or occupation. Despite continuing objections on the part of a handful of states, a consensus is evolving in favor of the view that human rights law applies in full alongside humanitarian law.

Once it is settled that human rights law does not cease to apply by reason of the inception of a state of armed conflict, it is easy to see how this body of law would apply alongside humanitarian law in an internal armed conflict. The situation becomes more complex, however, when a state is engaged in a non-international armed conflict taking place outside of that state's territory.

Unlike human rights law, the law of armed conflict was designed to apply primarily in an inter-state context. Thus, the vast majority of its provisions clearly apply to a state's extraterritorial conduct, specifically in the territory of the opposing state. But what of that branch of humanitarian law that developed to regulate non-international (i.e., non-inter-state) armed conflict? Recently, controversy arose as to whether Common Article 3 applies only to internal conflicts. The question of the extraterritorial application of Common Article 3 must be examined in light of the more general evolution in humanitarian law in favor of recognizing rights of individuals as such.

There has been a substantial degree of convergence between the law of international armed conflict and the law of non-international armed conflict. A result of this convergence has been that individuals involved in a non-international armed conflict can now benefit from many of the protections once available only in the context of inter-state conflicts.

At the same time, some have relied on this convergence to extend to non-international armed conflicts not only the prohibitions of the law of international armed conflict, but also, controversially, authorizations. In any event, notwithstanding continuing controversy over its content, there seems to be a general consensus supporting the proposition that the law of non-international armed conflict applies extraterritorially. As noted above, demonstrating the applicability of humanitarian law outside of a state's territory is facilitated by the fact that the bulk of the law of armed conflict was designed to apply in an interstate context, presupposing that states would be acting on each other's territory. That some of these rules are now deemed to apply even in an internal setting does not lessen the presumption that they will still apply extraterritorially, at least insofar as they consist of prohibitions and do not purport to impose obligations on third states.

The situation is more complex under human rights law, which was not primarily designed to apply extraterritorially. In order to ascertain whether human rights law is applicable in the context of transnational conflicts with non-state groups, it is essential to consider the extent to which human rights law is applicable in relation to individuals outside the state's territory.

Most of the jurisprudence of human rights bodies, which have greatly elaborated on the content of states' obligations under the various human rights treaties, has been developed in the context of alleged violations committed on the territory of the respective state party. Can these same standards be transposed onto the state's conduct abroad?

Thus, it would seem that there may be an identifiable trend toward recognizing varying levels of obligation. In particular, it may be that negative obligations apply whenever a state acts extraterritorially (at least with respect to intentional human rights violations, as opposed to indirect consequences), but that the degree of positive obligations will be dependent upon the type and degree of control (or power or authority) exercised by the state. Such obligations are limited by a scope of reasonableness even when applied to a state's conduct within its territory; there is no reason why application to a state's extraterritorial conduct would not similarly be bounded by a scope of reasonableness, such that the adoption of affirmative measures is only required when and to the extent that the relevant party de jure or de facto enjoys a position of control that would make the adoption of such measures reasonable. This approach would preserve the integrity of the respective treaties and would vindicate the universal nature of human rights, which is proclaimed in the preambles of all of the human rights treaties considered in this analysis. At the same time, it would not place unreasonable burdens on states parties. From its inception, the international law of armed conflict followed the projection of power. The jus in bello would apply to armed conflicts irrespective of physical location, so long as opposability as between the warring parties was satisfied. The same could be said of the law of state responsibility for injury to aliens. While the application of both bodies of law clearly extended beyond the state's jurisdictional reach, neither could penetrate into the sphere of the state's domestic jurisdiction in the narrowest sense. Human Rights law was developed to fill that gap.

But just as humanitarian law ultimately began to press inward against that external membrane of a state's domestic jurisdiction, human rights law has now begun to exert outward pressure against the inner wall of the state's jurisdiction. Indeed, these two processes—of inward penetration and outward projection—can be seen along a single continuum with a common seam. That seam is manifested in the structural evolution of the international legal system that was consolidated in the years immediately following World War II. The principal structural development of that period was the emergence of the individual human being as a subject of international law, capable of bearing international rights and duties.

This structural development corresponded to a coalescence of values around a principle conceived as transcendental and universal—human dignity. Recognition by the newly reconceived international community that the dignity of the individual human being was something entitled to legal protection led to the transformation of this principle into positive law. It is this conception of human rights as both transcendental and universal that pushes against the concept of jurisdiction—pushing simultaneously into the domestic sphere and out of it—and underscores both its artificiality and diminished existence. It is this conception, far more than the force of legal reasoning from positive law that has enabled both human rights law and humanitarian law to grasp the outer and inner reaches of the power of the state.

To the extent these rules are designed to protect individuals from abuses of state power, realization of that design entails application coextensive with the projection of that power. While the exact contours of their application may not be settled, the traditional principles of good faith and reasonableness in the circumstances provide ample guidance for shaping those contours.

Do the protections provided by the core international human rights treaties apply extraterritorially, outside the government-governed relationship, during periods of armed conflict and military occupation? The traditional view has been that human rights are essentially applicable in peacetime while humanitarian law (i.e. the law of war) governs situations of armed conflict and military occupation. More recently, a conflicting school of thought, reflected in decisions of the ICJ and the UN treaty bodies, has concluded that the law of war no longer automatically excludes the law of peace. But, while these views are entitled to respect, the international human rights instruments (unlike the regional human rights instruments) do not grant the treaty bodies or any other entity the authority to issue legally binding views on the nature of state obligations under the treaties. Applying the standard rules for treaty interpretation leads to the conclusion that the international human rights treaties apply in the context of armed conflict only with respect to acts of a state's armed forces executed within its own territory.

The spatial test for triggering the extraterritorial application of the main treaties on civil and political rights law has been the subject of significant judicial comment in recent years. This piece offers a critical evaluation of an important common theme in these judicial determinations: the suggestion that the spatial test is to be understood in a manner that covers a sub-set of extraterritorial activity involving territorial control occurring as a matter of fact. It provides a sustained explanation and critical evaluation of four different ways such a suggestion can be identified in some of the key judicial determinations on the issue of the extraterritorial application of treaties on civil and political rights generally. Since one of the other main areas of law potentially relevant to extraterritorial activity—the law of occupation—also uses a test of territorial control as a trigger for application, the interplay between the approaches taken in each area of law on the question of what type of control is required mediates the extent to which the fields of activity covered by the two areas of law overlap. Understanding the merit of the determinations concerning human rights law discussed in this piece is significant, then, not only on its own terms, but also because of its significance to the broader question of the overlap between human rights law and the law of occupation.

This article considers how arguments relating to the principle of joint applicability of international human rights law (IHR) and international humanitarian law (IHL) are playing out in the United Kingdom's courts. The core of the article is a case study of the decisions of the Divisional Court, the Court of Appeal and the House of Lords in Al-Skeini v. Secretary of State for Defence. The central issues of the case concerned the application of the UK's European Convention on Human Rights (ECHR) obligations in the context of its activities in Iraq, and the extraterritorial application of the Human Rights Act, 1998. This case study of the domestic application of the principle is particularly useful for considering (i) its practical implications on the specific facts of particular cases; (ii) the argumentation used by the UK government and judges; (iii) the difficulties of national courts in analyzing the IHR and IHL rights jurisprudence; and (iv) the significant differences between IHR and IHL in terms of positive obligations and domestic remedies.

This article asserts that a challenge exists in deflecting the prevailing view that a general gap of legal applicability exists in respect of legal regulation of the war on terror. This “gap” is articulated by a focus on a new phenomena—namely the emergence of Al Qaeda as a non-nationally motivated, transnational terrorist organization whose actions and actors do not “fit” existing legal norms and sanctions. In addressing that challenge, this article will rebut the argument that suggests a legal lacuna exists, and that no appropriate legal tools are available to states and international organizations as they confront the post September 11th context. In particular, the argument asserts that existing legal norms provide sufficient coverage to respond to the conflicts experienced in the contemporary moment, as well as to the state and non-state entities participating in them. The article suggests that clarity about the boundaries between the legal regime of international human rights law and international humanitarian law would assist closing off perceived regulatory gaps. It contends that the usual rationale given in favor of parallel application, namely higher protection for the victims of conflict, substantially underestimates its other valuable policy and instrumental benefits. Specifically, the traditionally vaunted victim centered rationale does not sufficiently weigh the value of affirming consistent rule of law coverage to situations of conflict. The article asserts that while further regulatory measures may be possible and even desirable to confront the contemporary challenges of conflict forms (including terrorism), a combined or dynamic approach to the law of war and international human rights law provides sufficient traction and norm content to address and be relevant to present needs.

Two different theories attempt to reconcile problems of application of international human rights law in time of armed conflict, to the extent that there is a potential conflict with norms set out in international humanitarian law. One, posited by the International Court of Justice, presents international humanitarian law as the lex specialis, a kind of prism through which the concept of “arbitrary deprivation of life” (Article 6(1) International Covenant on Civil and Political Rights) is to be understood in time of armed conflict. In effect, international humanitarian law supplants international human rights law during armed conflict. The other theory, advanced by the Human Rights Committee, views the two bodies of law as additive in effect. Both regimes apply, and the individual benefits from the more favorable one (“belt and suspenders” approach). Both theories profess the fundamental compatibility of the two different legal systems, yet they are predicated upon a method for resolving conflicts between them. Both theories encounter serious problems in their application. The author submits that the difficulty with these attempts to reconcile human rights law and humanitarian law lies with the failure to grasp an underlying distinction: international humanitarian law is built upon neutrality or indifference as to the legality of the war itself. Human rights law, on the other hand, law views war itself as a violation. There is a human right to peace. Because of this fundamental incompatibility of perspective with regard to jus ad bellum, human rights law and international humanitarian law can only be reconciled, as both the International Court of Justice and the Human Rights Committee desire, if human rights law abandons the right to peace and develops an indifference to the jus ad bellum. It too must accept the idea of the acceptability of “collateral” killing of civilians in war, even if the war itself is illegal. The author argues that it is preferable not to attempt to find a neat and seamless relationship between international humanitarian law and international human rights law, in the interests of preserving the pacifist strain within international human rights law.

This article asserts there has been a lack of attention to the impact of cultural diversity within the field of international humanitarian law. Discussions surrounding culture in international humanitarian law have nearly always avoided the central issue of cultural particularism. This has been so in relation to the debate surrounding the emblem, in general surveys of humanitarian law, and in discussions of the laws of war in distinct legal and cultural traditions. The emblems debate, in particular, signals the elusiveness of rigid universality within international humanitarian law. Five elements are suggested to explain the resistance of humanitarian law to contagion by the cultural relativism debate in human rights: the nature of human rights, the distinct normative frameworks of human rights and humanitarian law, the unified conventional basis of humanitarian law, the very broad participation in the humanitarian regime, and the unique role of the International Committee of the Red Cross. While these reasons might explain the fact that the relativism debate in human rights did not readily transfer to humanitarian law, they offer no substantive basis for immunity for humanitarian law to the challenges posed by cultural diversity. Ultimately, the article proposes a legal pluralist approach that recognizes the role of actors in the cultural process of norm-creation. Given the continued violation of the laws of war, the author suggests a need to open the door to cultural diversity in order to generate greater compliance. Without cultural legitimacy, there is a danger that humanitarian law aspires to self-defeating universalism.

This article provides a critical examination of the debate over the relationship between international humanitarian law and international human rights law. On the question surrounding the very fact of co-application, it appears that the dominant view supports the co-applicability of the two legal regimes. Opinion is however far from settled on the scope of application of international human rights law, especially insofar as it relates to the issue of extra-territorial applicability. The approach taken in the event of co-applying the two frameworks to specific circumstances, and whether and how one is to use the doctrine of lex specialis, reveals further questions in need of coherent answers. Finally, there remain particular areas in which the co-application faces challenges that must be surmounted, if it is to prove a useful approach. These include the issues of the so-called “war on terror,” the distinction between the jus ad bellum and the jus in bello, non-international armed conflicts, and more. Whilst the co-application of the two regimes is now almost undisputed, it appears therefore that obstacles remain that must be dealt with in order for the relationship of the regimes to be of a fully harmonious nature.