Blurring the lines between international and non-international armed conflicts - the evolution of customary international law applicable in internal armed conflicts.

• Author: Crawford, Emily

Abstract

This article looks at the emergence and evolution of the customary international humanitarian law applicable in situations of non-international armed conflict. In the years since the adoption of the Geneva Conventions and the Additional Protocols, a large number of rules relating to conduct in armed conflict have crystallised as customary international law, applicable in all instances of armed conflict. The significance of such development is that there are far fewer treaty rules regulating conduct in non-international armed conflict than in international armed conflict. Customary international humanitarian law has 'stepped in' to fill in many of the lacunae in the current treaty law of non-international armed conflict. It is now possible to speak of a comprehensive body of rules that are applicable in all instances of armed conflict. 21st century armed conflict continues to evolve and defy traditional definitions of armed conflict as mainly the preserve of sovereign States. Any harmonisation of the law relating to armed conflict can only be beneficial in ensuring that more of these non-traditional armed conflicts fall within the regulatory scope of the law of war.

Introduction

When the 1974-1977 Diplomatic Conferences negotiated the draft of what would become Protocol II Additional to the Geneva Conventions of 1949, (1) the question arose as to where one of the enduring principles of the treaty law of International Humanitarian Law ('IHL'), the Martens Clause, (2) would go. (3) The Clause had been included in the body of Protocol I Additional to the Geneva Conventions, (4) as well as the four Geneva Conventions of 1949. (5) When debate turned to the place of the Martens Clause in Protocol II, the Diplomatic Conferences inserted the Clause in the Preamble only and not in the main body of the Protocol. More significantly, however, the traditional formulation of the Martens Clause was amended. The Martens Clause, as included in Protocol II, states that '... in cases not covered by the law in force, the human person remains under the protection of the principles of humanity and the dictates of public conscience.' (6) Though the reformulation broadened the scope of the Martens Clause from the categories of 'civilians' and 'belligerents/combatants' to simply 'the human person', it was at the same time significantly limited by dropping the reference to 'the law of nations/international law' and 'established custom.' The Commentary to the Additional Protocols explains that the deliberate omission of any reference to 'established custom' is:

... justified by the fact that the attempt to establish rules for a non-international armed conflict only goes back to 1949 and that the application of common Art 3 in the practice of States has not developed in such a way that one could speak of 'established custom' regarding non-international armed conflicts. (7) However, less than thirty years later, the United Nations ('UN') Commission of Enquiry on Darfur noted:

... that a body of customary rules regulating internal armed conflicts has thus evolved in the international community... some States in their military manuals for their armed forces clearly have stated that the bulk of international humanitarian law also applied to internal conflicts. Other States have taken a similar attitude with regard to many rules of international humanitarian law. (8) In this respect, the Commission was referring to the military manuals of Germany and Britain, (9) and to a number of comments made by the United States over the previous decades, regarding what it considers to be the general principles governing conduct in internal armed conflicts. (10) The Commission on Darfur also noted that the inclusion of internal violations of IHL in the International Criminal Court ('ICC') Statute 'proves that the general legal view evolved in the overwhelming majority of the international community ... to the effect that (i) internal armed conflicts are governed by an extensive set of general rules of international humanitarian law; and (ii) serious violations of those rules may involve individual criminal liability.' (11)

The statements of the Darfur Commission present a significant reversal from the position in 1977 that there was no discernable customary international law regarding non-international armed conflicts. Over the past thirty years, there has been a general extension of rules of the law of international armed conflict to situations of non-international armed conflict. This is in addition to Common Article 3 and certain provisions of Additional Protocol II achieving customary status.

This article examines the development of customary international rules applicable in internal armed conflicts. In doing so, this article will demonstrate how customary international law has evolved to fill in most of the lacunae in the law regulating non-international armed conflicts, particularly those areas relating to the permissible means and methods of combat. It will be concluded that the law relating to non-international armed conflicts has evolved to the stage that there is considerable parity with the laws regulating international armed conflicts. The importance of this convergence will be examined in the final part of this article, where it will be concluded that this convergence in the law lays the groundwork for greater, if not universal, application of the laws applicable in international armed conflict to all armed conflicts.

1. Preliminary Comments on Customary International Law

Before turning to the identification of the relevant customary rules, it is useful to briefly discuss the rules for the formation of customary international law, and some of the debate regarding the development of customary international law rules. (12)

1. State Practice

   In ascertaining whether a certain rule can be considered customary, two elements must exist--State practice and opinio juris. The Statute of the International Court of Justice ('ICJ') (13) defines custom as 'evidence of a general practice accepted as law.' (14) State practice is the 'actual' or 'physical' acts of States in their relations with other States. (15) With regards to the practical elements that comprise State practice, these can include international agreements, the decisions of national and international courts and tribunals, the national law of States, and, to a lesser extent, the practice of international organisations, the declarations and resolutions of the UN General Assembly and Security Council, and the opinions and writings of publicists. (16)

   In order for practice to be considered constitutive of custom, the ICJ determined in the North Sea Continental Shelf Cases that 'State practice, including that of States whose interests are specially affected, should ... [be] both extensive and virtually uniform.' (17) 'Virtually uniform' does not mean absolutely uniform. So long as the State practice is sufficiently similar, then too much importance should not be attached 'to a few uncertainties or contradictions, real or apparent.' (18) Indeed, instances of non-compliance with a rule do not necessarily mean that the rule does not exist or that its customary status has been undermined. So long as the contrary practice is condemned as a breach of international law or denied by the State itself, the rule in question is confirmed. As noted by the ICJ in the Nicaragua case:

   In order to deduce the existence of customary rules, the Court deems it sufficient that the conduct of States should, in general, be consistent with such rules, and that instances of State conduct inconsistent with a given rule should generally have been treated as breaches of that rule, not as indications of the recognition of a new rule. If a State acts in a way prima facie incompatible with a recognised rule, but defends its conduct by appealing to exceptions or justifications contained within the rule itself, then whether or not the State's conduct is in fact justifiable on that basis, the significance of that attitude is to confirm rather than weaken the rule. (19) Practice need not encompass all States, but should include the practice of States who are specially affected by the rule in question. (20) It is possible for there to be 'regional' custom, where the rules are applicable only in a certain geographic region, or between a certain group of States regardless of geography. (21)

   The practice in question must not encounter strong or consistent opposition from other States. If the practice is actively accepted, a customary rule may be considered to have crystallised. If States tacitly assent, through failure to object to the practice, acquiescence in the rule may be found to exist. The ICJ defined acquiescence as 'equivalent to tacit recognition manifested by unilateral conduct which the other part may interpret as consent.' (22) However, something more than just the appearance of 'acceptance' or 'acquiescence' must be demonstrated. (23) It must be shown that a State has 'clearly and consistently evinced acceptance' of the rule that an opposing State claims as fact. Failure to protest against a State's actions may not, in itself, be enough to amount to acquiescence. The Permanent Court of International Justice clarified this position, stating that the failure of a State to protest may only be considered as acquiescence 'only if such abstention were based on their being conscious of having a duty to abstain would it be possible to speak of an international custom.' (24)

   In addition, such acceptance must have itself affected the opposing State. That is to say, the opposing State must demonstrate its reliance on the presumed acquiescence, so that, if the State seeking to deny the existence of a rule were to in fact deny the rule, the opposing State 'in reliance of such conduct' would be forced 'detrimentally to change position or suffer some prejudice.' (25)

   At this point, note should be made of the...