La prueba pericial

The previous discussion raises the issue of attribution of an armed attack, in particular the question of whether the jus ad bellum recognises a right of self-defence against non-state actors, such as terrorist organisations. It is not yet a settled point as to whether a victim state must be able to attribute that attack to a state actor in order to lawfully resort to force in self-defence, or whether a state may respond to an armed attack perpetrated by a non-state actor. Under what circumstances can the actions of a non-state actor be attributable to a host state for the purposes of Article 51 of the UN Charter? How close must the connection be between the non-state actor and the host state for the host state to be fixed with legal responsibility for the actions of the non- state actor? Article 8 of the International Law Commission’s articles on state responsibility offers some helpful initial guidance, providing that the conduct of a:

person or group of persons shall be considered an act of a state under international law if the person or group of persons is in fact acting on the instructions of, or under the direction or control of, that state in carrying out the conduct.53

O’Connell submits that, on the basis of the ICJ’s decisions in Nicaragua, Oil

Platforms and The Wall, attribution of an armed attack to a state actor is an absolute requirement for self-defence, and that without it a victim state must use law

enforcement methods within the human rights framework.54

A reading of the jurisprudence suggests that the threshold for attribution to the host state is rather high. The ICJ in Nicaragua, in setting down a test of ‘effective control’, concluded that US participation in the financing, organisation, training, supplying and equipping of the Contras, and in the selection of targets, did not suffice for the

purpose of attributing to the US the acts perpetrated by the Contras. The ICJ noted that for, “this conduct to give rise to legal responsibility of the United States, it would in principle have to be proved that [the United States had] effective control of military and paramilitary operations in the course of which the alleged violations were

committed.”55 Whilst in Tadic,56 the Appeals Chamber of the International Criminal

53

See G.A. Res. 56/83 (12/12/01). 54

See O’Connell, supra n.42, at 590-591. 55

Tribunal for the Former Yugoslavia57 questioned the rationale behind this high threshold, opting instead for a less onerous test of “overall control”,58 the ICJ nevertheless reaffirmed the higher threshold in both the Armed Activities59 and the Genocide60 cases. In the latter case, the ICJ was clearly explicit in stating that “effective control” is required in respect of, “each operation in which the alleged violations occurred, not generally in respect of the overall actions taken by the person or group of persons having committed the violations”.61 The Court therefore utterly rejected the notion that the test for attribution was a variable one that was dependant on the nature of the act perpetrated in the absence of a clear lex specialis.62 Regardless of the test applied, the attribution requirement predicates a lawful use of force in self- defence upon the occurrence of an armed attack attributable to a state actor. Violent acts perpetrated unilaterally by a non-state actor would not be sufficient to trigger the right of self-defence.

As it stands, therefore, a host state is responsible for the actions of a non-state actor only if it exercises effective control over the non-state actor in the course of their operations. However, other scholars such as Dinstein maintain that attribution is not required and that a state possesses a right to use force in self-defence against a non- state actor, even when the actions of the non-state actor cannot be attributed to a host state.63 In other words, there is a free-standing right of self-defence against a non-state actor. A non-state actor can perpetrate an “armed attack” for the purposes of

triggering a state’s right to resort to force in self-defence under Article 51 of the UN Charter. This issue came to the fore following the 9/11 attacks, with the US arguing that the attacks triggered its right to use force against the Al-Qaeda terrorist network based in Afghanistan. The notion of a right to self-defence against non-state actors has been controversial. In The Wall, Judge Kooijmans noted, in his Separate Opinion in the ICJ’s Advisory Opinion, “for more than 50 years…it has been the generally

56

Prosecutor -v- Dusko Tadic (Judgment), ICTY-94-1 (15/07/99). Hereinafter referred to as Tadic. 57

Hereinafter referred to as the ICTY. 58

See Tadic, supra n.56, at paras.117 and 137. 59

See Armed Activities, supra n.33, at para.160. 60

See Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina -v- Serbia and Montenegro), [2007] ICJ Rep. 43.

61

Ibid, at para.400. 62

Ibid, at para. 401. 63

accepted interpretation”, that an armed attack must come from another state.64 Judge Kooijmans’ dictum is certainly reflective of the pre-9/11 prevailing interpretation of Article 51 that the armed attack must be perpetrated by the territorial state itself before it could be the legitimate target of force in self-defence directed at the perpetrators of the attack. However, as with the ‘accumulation of events’ doctrine discussed above, the 9/11 attacks seem to have heralded a shift in legal opinion on this issue. The response of the UN Security Council to the 9/11 attacks, which recognised the right of the United States to act in self-defence, did not itself set down state attribution as a condition precedent.65 Despite a few persistent objectors, notably Professor

O’Connell, who staunchly advocates the traditional view,66 for most scholars, the response of the international community in the aftermath of the 9/11 attacks indicates that, subject to certain conditions, there does exist, in the words of Gray, a, “right to self-defence against non-state actors for terrorist attacks.”67 Therefore, as Lubell rightly submits, there is plentiful evidence, reflected in state practice since 9/11 in relation to the interpretation of Article 51 of the UN Charter, to support the view that a non-state actor can be responsible for an armed attack that engages a victim state’s right to self-defence.68 It is of note that the report of Christof Heyns reflects this position, although Heyns points to an emerging view amongst commentators that the threshold of violence necessary to justify the use of force in self-defence ought to be set higher where the initial armed attack is perpetrated by a non-state actor. 69

Certainly, there is nothing in the wording of Article 51 referring to the nature of the party responsible for the armed attack, only the nature of the party entitled to resort to force in self-defence – there is no mention or qualification as to the nature of the perpetrator of the armed attack. However, although the weight of scholarly opinion may have shifted in favour of recognising the emergence of a right of self-defence against a non-state actor, to date this has yet to be reflected in the jurisprudence of the ICJ, with the Court thus far sceptical of the existence of such a right. In both The Wall and Armed Activities, the majority of the Court maintained the traditional

64

See Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory (Advisory Opinion), [2004] ICJ Rep. 136, Separate Opinion of Judge Kooijmans, at para.35. Hereinafter referred to as The Wall.

65

UNSC Res. 1368 (12/09/01) and UNSC 1373 (28/09/01). 66

See O’Connell, supra n.11. 67

See Gray, supra n.39, at 199. 68

See Lubell, supra n.39, at 31. 69

interpretation of Article 51 that excluded a right of self-defence against non-state actors.70 In both cases, the reasoning of the majority met with strong dissenting opinions.71 Judge Higgins opined that there was nothing in the wording of Article 51 to prohibit the use of force in self-defence where the armed attack was perpetrated by a non-state actor – the wording does not limit armed attacks to those attributable to an attacking state (such an apparent limitation being understood in light of the Nicaragua decision, with which the learned Judge expresses her own reservations).72 Similarly, Judges Kooijmans and Buergenthal, in The Wall, expressed deep dissatisfaction at the apparent reluctance of the ICJ to depart from Nicaragua and accept that armed attacks by non-state actors could engage the victim state’s right to resort to force in self- defence.73 It seems, therefore, that the jurisprudence of the ICJ and academic

scholarship on the issue are out of step with one another. Whilst there is an absence of judicial affirmation of such a right of self-defence against non-state actors, the weight of scholarship seems to have determined that such a right does exist, turning its focus to how such a right can be exercised lawfully. When, therefore, does the jus ad bellum permit a victim state to defend itself against terrorism?