To What Extent Is Protocol I Customary International Law?

• Author: Fausto Pocar
• Pages: 337

T o what extent does Protocol I1 reflect customary international law, such that it may be regarded as binding on non-party States? The question has been discussed since the early days following the entry into force of Protocol I, when the number of ratifying States was still rather thin.2 Indeed the frequent involvement of non-ratifying States in international armed conflicts made an answer to that question urgent, in order to establish the scope of application of the principles that the Protocol enshrines in a given situation. Notwithstanding the increase in the number of States parties,3 the problem continues to be topical, in particular because the countries that have not yet ratified the instrument, including some major actors in international relations, maintain serious reservations as to the binding force of one or more principles expressed and regulated therein.4 In this context, it has to be pointed out that attention has mainly focused on Part III (Articles 35 to 47) of Protocol I, dealing with methods and means of warfare and with the status of combatants and prisoners of war, as well as on Part IV (Articles 48 to 79), concerned with the 1. Protocol Additional (I) to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Conflicts, June 8, 1977, 1125 U.N.T.S. 3, DOCUMENTS ON THE LAWS OF WAR422 (A. Roberts &R. Guelff eds., 3d ed. 2000) [hereinafter Protocol I].

2. Protocol I entered into force on December 7, 1978. By 1980 only 16 States had become parties to Protocol I; they were Bahamas, Bangladesh, Botswana, Cyprus, Ecuador, El Salvador,

   Finland, Gabon, Ghana, Jordan, Laos, Libya, Niger, Sweden, Tunisia and Yugoslavia.

3. 59 States were parties to Protocol I as of August 21, 2001.

4. India, Indonesia, Iran, Iraq, Israel, Japan, Pakistan, Turkey and the United States are some of the States which have not ratified Protocol I so far.

   protection to be afforded to civilian populations; these two parts of the Protocol being in many respects linked to each other.

   It is undisputed that Protocol I is aimed both at codifying existing international law relating to the protection of victims of international armed conflicts and at developing such law in order to increase their protection. As the Preamble clearly states, the instrument is based on the necessity 'to reaffirm and develop the provisions protecting the victims of armed conflicts.'5 Thus, Protocol I itself explains that not all of its provisions simply codify existing law, though it declares at the same time that a number of them do so.

   One is therefore confronted with a problem common to the interpretation of all so-called codification conventions, i.e., the problem of identifying the treaty provisions that reflect customary international law, as opposed to those that make innovations or contain additional elements, thus developing the law's scope and content.6 The former will have general value in that they reproduce customary rules, while the binding force of the latter will be limited to the States having ratified pr acceded to the convention. This is in accordance with the general rule that treaties do not create either obligations or rights for a third State without its consent and that their effects are limited to State parties (pacta tertiis nec nocent nec prosunt).7

   In making this assertion, however, some points must be borne in mind.

   First, the abovementioned status of a treaty provision as reproducing or developing customary international law may change according to the time at which its status is assessed. A provision that did not reflect customary law when it was drafted may subsequently become a customary rule through its general application by States. Similarly, although less frequently, a provision which codified principles forming part of customary law when it was drafted may not reflect them at a later stage due to changes in general State practice. In dealing with this issue, reference should therefore be made to the point in time at which the question of the binding force of a specific treaty provision for non-contracting States arises.

5. Emphasis added.

6. See Richard Baxter, Treaties and Custom, 129 RECUEIL DES COURS 36 ff. (1970); Karl Zemanek, Die Bedeutung der Kodifizierung des Vilkerrechts fir seine Anwendung, in FESTSCHRIFT VERDROSS 565 (1971); Roberto Ago, Nouvelles riflexions sur la codification du droit international, 92 REVUE GENERALE DE DROIT INTERNATIONAL PUBLIC 539 (1988).

7. According to Article 34 of the Vienna Convention on the Law of Treaties (May 23, 1969, 1155 U.N.T.S. 331), 'A treaty does not create either obligations or rights for a third State without its consent.' Secondly, even when a treaty provision can be considered as codifying a norm of customary law, it is the latter that finds application as regards non-party States and not the treaty provision as such. As the International Court of Justice clarified in the Nicaragua case,8 the two norms derive from distinct sources of law and each continues to belong to a separate body of rules. Indeed, the Court stated:

   Even if the customary norm and the treaty norm were to have exactly the same content, this would not be a reason for the Court to hold that the incorporation of the customary norm into treaty-law must deprive the customary norm of its applicability as distinct from that of the treaty norm.... [T] here are no grounds for holding that when customary international law is comprised of rules identical to those of treaty law, the latter 'supervenes' the former, so that the customary international law has no further existence of its own.9

   Thus, their interpretation and application may be subject to different principles, although the treaty provision will have an impact in this context in that it constitutes an assessment of the relevant rule or principle made by the States which have entered into the treaty.

   Thirdly, as the codification process necessarily requires an assessment of the customary rule or principle concerned as well as a written definition thereof, the resulting written text may be regarded as affecting its scope and content. Consequently, any precision or new element that may have been added-as is normally the case-by the treaty provision to the principle of customary law which it codifies must be checked carefully in order to establish whether it has come to be accepted as generally applicable. However, the addition of new elements by a treaty provision to a customary principle should be distinguished from specifications deriving by necessary implication from the accepted general customary principle. As it has been pointed out,10 such specifications could not be regarded as requiring acceptance of the treaty in order to become applicable to a State. A different conclusion would result in allowing a limitation of the already accepted general principle that derives from 8. Military and Paramilitary Activities (Nicar. v. U.S.), 1986 I.C.J. 14, 94-5 (une 27) [hereinafter Nicaragua case].

9. Id. at 95.

10. See Georges Abi-Saab, The 1977 Additional Protocols and General International Law: Some Preliminary Reflections, in HUMANITARIAN LAW OF ARMED CONFLICTS: CHALLENGES AHEAD,

    ESSAYS IN HONOUR OF FRITS KALSHOVEN 120 (Astrid J.M. Delissen & Gerard J. Tanja eds., 1991), who mentions in this regard the rules concerning the protection of civilians against aerial bombardments in Protocol I.

    customary law. The inclusion of such necessary implications in a treaty provision cannot reduce in any way for non-party States the obligations they would have under the general principles from which those implications derive.

    The elements and factors to be taken into consideration in assessing State practice for the purposes of establishing the existence of customary rules and principles have been widely discussed in international legal doctrine and case law. This paper does not aim at revisiting all the features and implicati6ns of the problems arising in this area, including the issue of defining State practice.

    The main principles governing the matter have been already laid down by the International Court of Justice in the North Sea Continental Shelf case1 and in the Nicaragua case,12 whereby the Court has stressed the respective role of the practice of States and opinio juris as factors for identifying a customary rule of international law, as well as the place of treaty provisions codifying customary law in this regard. Following these judgments, there is no doubt that for a rule to exist as a norm of customary international law both its recognition as a legal obligation by States and the latter's conduct which is consistent with the rule are required.13

    Some issues deserve special consideration as far as the relationship between codified and customary rules is concerned. In this context, it has been discussed whether the practice of all States, including those which are parties to the treaty (in our case Protocol I), should be taken into account for the purposes of establishing the existence of a customary norm. A negative answer would diminish the number of States whose practice is...