NATO, the UN and the Use of Force: Legal Aspects

NATO, the UN and the Use of Force: Legal Aspects

1 The Threat or Use of Force in International Law

Contemporary international law establishes beyond any doubt that serious violations of human rights are matters of international concern. Impressive networks of rules and institutions, both at the universal and regional levels, have come into being as a result of this international concern. In the event of human rights violations which reach the magnitude of the Kosovo crisis, these developments in international law allow states, acting individually, collectively or through international organizations, to make use of a broad range of peaceful responses. According to the dominant doctrine in the law of state responsibility (developed by the United Nations International Law Commission), the obligation on states to respect and protect the basic rights of all human persons is the concern of all states, that is, they are owed erga omnes . Consequently, in the event of material breaches of such obligations, every other state may lawfully consider itself legally "injured" and is thus entitled to resort to countermeasures (formerly referred to as reprisals) against the perpetrator. Under international law in force since 1945, confirmed in the General Assembly's Declaration on "Friendly Relations" of 1970, ¹ countermeasures must not involve the threat or use of armed force. In the case of Kosovo, pacific countermeasures were employed, for instance, by the European Union last year, with the suspension of landing rights of Yugoslav airlines within the EU. Leaving aside the question of whether this particular measure proved to be effective, it is somewhat surprising that a major Member State of the EU, at least initially, did not regard itself in a position legally to have recourse to this peaceful means of coercing the FRY to respect the human rights of the Kosovar Albanians. Yet it expressed no such doubts about the legality of its participation in the NATO threat of armed force which developed just a few weeks later.

The world community, for its part, acting through the United Nations Security Council, resorted to a mandatory arms embargo vis-à-vis the FRY, including Kosovo. ² We do not have the necessary information at hand to be able to give a sound assessment of the impact and effectiveness of these non-military measures.

In the face of genocide, the right of states, or collectivities of states, to counter breaches of human rights most likely becomes an obligation. 3 In Kosovo, however, what the international community is facing are massive violations of human rights and rights of ethnic minorities, but not acts of genocide in the sense of the 1948 Convention. ⁴

Turning to the issue of enforcement of respect for human rights by military means, the fundamental rule from which any inquiry must proceed is Article 2(4) of the UN Charter, according to which

[a]ll Members [of the UN] shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.

It is clear, on the basis of both a teleological and historical interpretation of Article 2(4), that the prohibition enacted therein was, and is, intended to be of a comprehensive nature. Thus, contrary to certain views expressed during the Cold War years, the phrase "... or in any other manner inconsistent ..." is not designed to allow room for any exceptions from the ban, but rather to make the prohibition watertight. In contemporary international law, as codified in the 1969 Vienna Convention on the Law of Treaties (Articles 53 and 64), the prohibition enunciated in Article 2(4) of the Charter is part of jus cogens , i.e., it is accepted and recognized by the international community of states as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same peremptory character. Hence, universal jus cogens , like the prohibition embodied in Article 2(4), cannot be contracted out of at the regional level. Further, the Charter prohibition of the threat or use of armed force is binding on states both individually and as members of international organizations, such as NATO, as well as on those organizations themselves.

Moreover, it is important to draw attention to Article 52 of the just-mentioned Vienna Convention, according to which "[a] treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations', paramount among these principles being Article 2(4).

The law of the UN Charter provides two exceptions from the prohibition expressed in Article 2(4) (the mechanism of the so-called "enemy-state-clauses" (Articles 53 and 107) should be left aside as it is now unanimously considered obsolete). The first exception, embodied in Article 51 of the Charter, is available to states which find themselves to be victims of aggression:

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

As the Charter reference to collective self-defence, Article 51 constitutes the legal foundation of the Washington Treaty by which NATO was established. ⁵ Article 5 of the NATO Treaty bases itself expressly on Charter Article 51.

According to the UN Charter, then, individual or collective self-defence through the use of armed force is only permissible in the case of an "armed attack". Like Article 2(4), Article 51 has become the subject of certain gross (mis-)interpretations, most of them put forward during the Cold War when the Security Council regularly found itself in a state of paralysis. Against such attempts to turn a clearly defined exception to the comprehensive Charter ban on the threat or use of force into a convenient basis for all sorts of military activities, it should be emphasized once again that Article 51 unequivocally limits whatever farther-reaching right of self-defence might have existed in pre-Charter customary international law to the case of an "armed attack". In particular, any offensive self-help by threats or use of armed force without a basis in Chapter VII has been outlawed by the jus cogens of the Charter.

With regard to the second exception to the Charter ban on armed force, Chapter VII constitutes the very heart of the global system of collective security. According to its provisions, the Security Council, after having determined that a threat to the peace, breach of the peace, or act of aggression has occurred, may, if necessary, take military enforcement action involving the armed forces of the Member States. In actual UN practice, it is now common for such enforcement action to be carried out on the basis of a mandate to, or more frequently an authorization of, states which are willing to participate, either individually or in ad hoc coalitions or acting through regional or other international organizations, among them prominently NATO. While the implementation of Chapter VII through a "franchising system" of this kind creates numerous problems of its own, it is universally accepted that a Security Council authorization granted under Chapter VII establishes a sufficient basis for the legality of the use of armed force employed in conformity with the respective Council Resolution(s). Conversely, any threat or use of force that is neither justified as self-defence against an armed attack nor authorized by the Security Council must be regarded as a violation of the UN Charter.

Chapter VIII of the Charter (Regional arrangements) completes the legal regime thus devised. Hence, according to Article 53 para. 1,

[t]he Security Council shall, where appropriate, utilize such regional arrangements or agencies for enforcement action under its authority.

The UN Secretary-General's 1992 "Agenda for Peace" emphasized the desirability, indeed necessity, of this mechanism of support. ⁶ The provision then continues:

But no enforcement action shall be taken under regional arrangements or by regional agencies without the authorization of the Security Council [with the now obsolete exception of the employment of the "enemy-state-clauses"].

This provision, too, has been subjected to considerable strains, particularly during the Cold War. One especially dubious example is the view that the failure of the Council to disapprove regional military action amounts to (tacit) authorization. In view of the veto power of the permanent Council members, this is a specious argument. On the other hand, an interpretation of Article 53 para. 1 does in good faith leave room for the possibility of implicit as well as ex-post-facto authorization.

Before concluding this brief tour d'horizon of the relevant international law in force, reference must also be made to Article 103 of the Charter, according to which

[i]n the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreement, their obligations under the present Charter shall prevail.

Prominent among the Charter obligations thus enjoying priority is, of course, the prohibition on the threat or use of force embodied in Article 2(4), in the context of the other provisions of the Charter to which reference is made above (Articles 51 and 53, Chapter VII). Since Article 2(4) reflects a norm of jus cogens , any agreements, decisions and obligations conflicting with it are invalid. Hence, Article 103 renders the UN Charter itself, as well as the obligations arising under it from, for instance, binding Security Council decisions, a "higher law" vis-à-vis all other treaty commitments of the UN Member States, among them those stemming from NATO membership. ⁷

The question of the legality versus the illegality of so-called "humanitarian intervention" must be answered in light of the foregoing. Thus, if the Security Council determines that massive violations of human rights occurring within a country constitute a threat to the peace, and then calls for or authorizes an enforcement action to put an end to these violations, a "humanitarian intervention" by military means is permissible. In the absence of such authorization, military coercion employed to have the target state return to a respect for human rights constitutes a breach of Article 2(4) of the Charter. Further, as long as humanitarian crises do not transcend borders, as it were, and lead to armed attacks against other states, recourse to Article 51 is not available. For instance, a mass exodus of refugees does not qualify as an armed attack. In the absence of any justification unequivocally provided by the Charter "the use of force could not be the appropriate method to monitor or ensure ... respect [for human rights]", to use the words of the International Court of Justice in its 1986 Nicaragua judgment. ⁸ In the same year, the United Kingdom Foreign Office summed up the problems of unilateral, that is, unauthorized, humanitarian intervention as follows:

the overwhelming majority of contemporary legal opinion comes down against the existence of a right of humanitarian intervention, for three main reasons: first, the UN Charter and the corpus of modern international law do not seem to specifically incorporate such a right; secondly, State practice in the past two centuries, and especially since 1945, at best provides only a handful of genuine cases of humanitarian intervention, and, on most assessments, none at all; and finally, on prudential grounds, that the scope for abusing such a right argues strongly against its creation ... In essence, therefore, the case against making humanitarian intervention an exception to the principle of non-intervention is that its doubtful benefits would be heavily outweighed by its costs in terms of respect for international law. ⁹

The question which arises at this point is, of course, whether the state of the law thus described could have changed in recent years, possibly after the demise of the East-West conflict or under the shock of the genocide and crimes against humanity occurring in the former Yugoslavia. Could it not be that recent "humanitarian interventions", undertaken in the spirit of ensuring that Srebrenica does not happen again, as it were, deserve a friendlier reaction also on the part of international lawyers? Do recent instances of "military humanitarianism" show themselves to be uninfected by the less laudable motives that characterized such actions in the past? To what extent will collective decision-making, or the involvement of NATO or the OSCE as such, guarantee that such improper motives are restrained or even eliminated? And, most importantly, how could even the purest humanitarian motives behind military intervention overcome the formidable international legal obstacles just described? These obstacles could only be removed by changing the law of the UN Charter. There is no prospect of such a change, however. Thus, "humanitarian interventions" involving the threat or use of armed force and undertaken without the mandate or the authorization of the Security Council will, as a matter of principle, remain in breach of international law. But such a general statement cannot be the last word. Rather, in any instance of humanitarian intervention a careful assessment will have to be made of how heavily such illegality weighs against all the circumstances of a particular concrete case, and of the efforts, if any, undertaken by the parties involved to get "as close to the law" as possible. Such analyses will influence not only the moral but also the legal judgment in such cases.

1 GA Res. 2625 (XXV) (1970).

2 Operative para. 8 of SC Res. 1160 (1998).

3 Cf. the judgment of the International Court of Justice in the Genocide (Bosnia-Herzegovina v. Yugoslavia ) case (1996).

4 Convention on the Prevention and Punishment of the Crime of Genocide, 1948.

5 North Atlantic Treaty (1949), 34 UNTS 243.

6 Boutros Boutros-Ghali, An Agenda for Peace (1992) SC Doc. S/24111, 17 June 1992.

7Cf. in this regard Art. 7 of the NATO Treaty.

8 ICJ Reports (1986), at para. 268.

9 UK Foreign Office Policy Document No. 148, reprinted in 57 BYbIL (1986) 614.

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