A Right of Anticipatory Self-Defence?

As stated, a victim state’s right to use force in self-defence under Article 51 of the UN Charter is triggered when an armed attack “occurs”. Notwithstanding this express and clear wording of Article 51, it is submitted that there are limited circumstances when a state may resort to force in anticipatory self-defence against an expected, imminent, armed attack.74 This view was expressed by the UN Secretary-General’s High-Level Panel on Threats, Challenges and Change, in 2004:

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See remarks of the Court in The Wall, supra n.64, at para.139: “Article 51 thus recognises the existence of an inherent right of self-defence in the case of armed attack by one state against another state”. See also Armed Activities, supra n.33, at para.146ff, where the Court had to rule on the legality of Ugandan use of force in the DRC. In rejecting the compatibility of that use of force with the right to self-defence, the Court listed a number of reasons, inter alia, that the relevant acts, which according to Uganda triggered its right to self-defence, could not be directly attributed to DRC.

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See The Wall, supra n.64, Separate Opinion of Judge Kooijmans, at para.35, and Separate Opinion of Judge Higgins, at para.32. See also Declaration of Judge Buergenthal, at para.6. See also Armed Activities, supra n.33, Separate Opinion of Judge Kooijmans, at para.29, and Separate Opinion of Judge Simma, at para.8.

72

See Higgins, Ibid. 73

See Kooijmans and Buergenthal, supra n.71. 74

…a threatened state, according to long established international law, can take military action as long as the threatened attack is imminent, no other means would deflect it and the action is proportionate.75

David Bethlehem offers some helpful guidance on the assessment of whether an armed attack is to be regarded as ‘imminent’, opining that same is to be assessed by reference to all relevant circumstances, including: (a) the nature and immediacy of the threat; (b) the possibility of an attack; (c) whether the anticipated attack is part of a continuous and concentrated armed activity; (d) the probable scale of the attack and the injury, harm, loss or damage likely to result therefrom in the absence of action taken to mitigate the effects of same; and (e) the likelihood that there will be other opportunities to undertake effective action in self-defence that may reasonably be expected to cause less serious collateral damage to civilians and civilian objects. So long as there is a reasonable and objective basis for concluding that an armed attack is imminent, a lack of specific evidence or knowledge of when and where an attack will take place, or the precise nature of that attack, will not be fatal to a conclusion that the armed attack is imminent and thus will not preclude a legitimate claim of self-

defence.76

While the original formulation of the right to self-defence in Caroline clearly

envisaged the possibility that a state may be required to use force in anticipation of an armed attack, it is submitted that the Caroline formula does not recognise the wider notion of pre-emptive, self-defence against future attacks that are neither specific nor imminent. However, Article 51 of the UN Charter is not a carbon copy of the original Caroline formula. Indeed, by seeming to permit force in self-defence only when an armed attack occurs, Article 51 seems to be more restrictive than the original formulation, by, prima facie, excluding the possibility of self-defence against future attacks, irrespective of their degree of imminence. This apparent exclusion of the possibility of legitimate anticipatory self-defence certainly finds a basis in the travaux préparatoires of the UN Charter, which indicates that the drafters did not wish the

75

Report of the Secretary-General’s High-Level Panel on Threats, Challenges and Change, ‘A More Secure World: Our Shared Responsibility’, A/59/565 (02/12/04), at 188.

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See Bethlehem, ‘Principles of International Law on the Use of Force by States in Self-Defence’, The Royal Institute of International Affairs, Chatham House, London, October 2005, at 21.

right of self-defence to be engaged before the occurrence of an armed attack.77 Furthermore, Brownlie submits that, “it can only be concluded that the view that Article 51 does not permit anticipatory action is correct, and that arguments to the contrary are either unconvincing or based on inconclusive pieces of evidence.”78 However, support for such a view is not absolute, with Bowett submitting that such a restriction is, “both unnecessary and inconsistent with Article 2(4), which forbids not only force but the threat of force, and, furthermore, it is a restriction which bears no relation to the realities of a situation which may arise before an actual attack and call for self-defence immediately if it is to be of any avail at all.”79

Is it therefore possible to reconcile a notion of anticipatory self-defence with Article 51 of the Charter? One possibility lies in the wording of Article 51 itself, which speaks of the “inherent” right of a state to resort to force in self-defence. The wording itself does not preclude a pre-existing anticipatory component of this inherent right. This possibility finds favour with Higgins, who states that it, “is also contended that the continued validity of this pre-Charter law on anticipatory self-defence is

consistent with the reference in Article 51 to the right of self-defence being “inherent”.”80 A further possibility is that, while the use of force in self-defence against an attack that has not yet occurred may be proscribed by law, it may be tolerated by the international community in certain, limited circumstances. Gray submits that there is state practice in support of a general acceptance, or at least a quiet tolerance, of the use of force in anticipatory self-defence, provided that the strict necessity and immediacy requirements of the Caroline formula are not deviated from.81

Jennings and Watts state:

The better view is probably that while anticipatory action in self-defence is normally unlawful, it is not necessarily unlawful in all circumstances, the matter depending on

77

See Governor Stassen (US team), Minutes of the 48th meeting of the US delegation, San Francisco 20th May 1945, 1 Foreign Relations of the United States of America (1945) 813, at 818.

78

See I. Brownlie, International Law and the Use of Force by States, (OUP, 1963), at 278. 79

See D. Bowett, Self-Defence in International Law, (Manchester University Press, 1958), at 191-192. 80

See Higgins, ‘The Attitude of Western States Towards Legal Aspects of the Use of Force’, in A. Cassesse (ed), The Current Legal Regulation of the Use of Force (Martinus Nijhoff: Dordreht, 1986), at 442.

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the facts of the situation, including, in particular, the seriousness of the threat and the degree to which pre-emptive action is really necessary and is the only way of avoiding that serious threat. The requirements of necessity and proportionality are probably even more pressing in relation to anticipatory self-defence than they are in most other circumstances.82

It is not impossible to arrive at an altogether similar conclusion when considering the issue of anticipatory self-defence against a non-state actor, such as a terrorist group. The Caroline case itself dealt with the issue of self-defence against a non-state actor, and the formula set out therein is still regarded as legitimising a limited notion of anticipatory self-defence. It is, therefore, arguable that there exists in international law a limited right of anticipatory self-defence against a non-state actor.

Therefore, if one accepts that, in certain limited circumstances, a state may be left with little option but to resort to force in anticipatory self-defence against another state, the same must be true when there is a necessity to use force in the face of a direct and imminent attack from a non-state actor, particularly if that attack may be on a large scale. The reality of the threat posed by non-state actors such as Al-Qaeda, Boko Haram, Al-Shabaab, et al, certainly lends itself favourably to recognising the existence of such a right. That being said, this reality should not translate into

recognition of a broader right of pre-emptive self-defence, which would permit a state to resort to force on a pre-emptive basis, with no requirement of prior knowledge of a specific imminent attack.