Airstrikes, Iraq, and the Islamic State: An Emerging Role for Self-Defense Under International Law

C. Elizabeth Bundy, Associate Editor, Michigan Journal of International Law

Exercising a claim of collective self-defense as enshrined in Article 51 of the U.N. Charter, the United States is currently assisting Iraq in addressing armed attacks carried out by the Islamic State. As historically construed under the Charter, Article 51 represents an exception to Article 2(4)’s prohibition on the threat or use of force against any state and therefore clearly endorses the right of self-defense against sovereign nations. Two issues at stake in the current conflict present a challenge to the conventional understanding of this framework: U.S. operations are directed at a non-state actor, and the threats posed by that actor are not restricted to Iraqi territory but extend to Syria. Although the United States has long claimed that it is justified in encroaching on the territory of a state that is unwilling or unable to exercise a threat emanating from within,[i] the variance of international opinion as to this question suggests that a norm governing the right to self-defense against non-state actors has not yet crystalized.[ii] The question remains as to whether a norm justifying U.S. incursion may be in the process of developing, but greater specificity of that norm is needed for a stronger consensus to emerge. On the one hand, the Security Council Resolutions 1368 and 1373, adopted in the wake of the 9/11 attacks, may be read as upholding the right of self-defense against non-state actors.[iii] However, the legal reservations recently expressed by Australia, France, the United Kingdom, and the Netherlands in response to U.S. airstrikes inside Syria[iv] seem to suggest that a consensus justifying the exercise of collective self-defense absent additional consideration of its consequences has not yet emerged. In exploring the history of this emerging norm, perhaps the most authoritative acknowledgement of the right to self-defense against non-state actors is that of the Security Council in the aftermath of the 9/11 attacks. Resolution 1368 affirms the United States’ right to self-defense under Article 51 of the U.N. Charter;[v] the fact that Al-Qaeda was the non-governmental entity that had initiated the armed attack supports the inference that self-defense may be linked to non-state actors. The invocation of the Security Council’s binding Chapter VII authority in reaffirming this right in Resolution 1373[vi] after the identity of the attackers had been confirmed further upholds this inference, even in the absence of an affirmative recognition as against non-state actors generally. NATO’s Statement by the North Atlantic Council regarding the September 11th attacks similarly provides a useful point of inquiry as to states’ responses to attacks by non-state actors. The Statement recognizes that, notwithstanding the very different circumstances under which “the commitment to collective self-defense embodied in the Washington Treaty was first entered into,” the right to self-defense “remains no less valid and no less essential today, in a world subject to . . . international terrorism.[vii]” Unlike the Security Council Resolutions, the Statement expressly acknowledges the changing nature of threats to international security and reflects the need to reevaluate the right of self-defense in light of these changes.[viii] The NATO country members’ stance thus seems to be in alignment with the dynamic approach, advocated by many, that “self-defense is not a static concept but rather one that must be reasonable and appropriate to the threats and circumstances of the day.[ix]” A third instance of recognition of the right to self-defense against non-state actors may be observed in the international community’s response to Israel’s 2006 offensive into Lebanon to address attacks carried out by Hezbollah. The statements of various countries’ delegates to the Security Council reaffirmed Israel’s right to self-defense even as they condemned the exercise of that right as going beyond proportionate measures.[x] It is notable that some delegates spoke to Lebanon’s obligation to “ restore its sovereignty . . . and to exercise the sole rights to the use of force on [its] territory” in addressing the threat to Israel emanating from Lebanese territory.[xi] Their statements, combined with the general recognition of Israel’s right to self-defense, indicate evidence of an emerging norm permitting self-defense against non-state actors, potentially where a state is “unwilling or unable” to address the threat itself. Notwithstanding these developments, there is still need to clarify this right with sufficient specificity such that clear guidelines are available to govern nations invoking the right to self-defense. Given the International Court of Justice’s reluctance to affirm this right in two separate opinions, a perceived reluctance among U.S. allies to accept such a norm is understandable in the context of the current conflict in Syria. One of the concerns underlying the ICJ opinions seems to pertain to the broad delegation of authority to those exercising the right to self-defense that might result were the Court to recognize a right to respond to perceived acts of aggression by non-state actors.[xii] As evinced in the Court’s advisory opinion on the legal consequences of the Israel-constructed wall in Palestinian territory, a related issue might concern the implications such authority would hold for the sovereignty of the states or territories from which threats are said to emanate.[xiii]  The court circumvents these concerns in the Wall opinion by pointing to Israel’s failure to impute the attacks against it to a sovereign state,[xiv] and again in the DRC opinion by finding that the initial armed attacks committed against Uganda by irregular forces could not be attributed to the Democratic Republic of the Congo.[xv] That a failure to impute armed attacks to the sovereign state from which they originated in both cases resulted in illegitimate exercises of self-defense thus supports a conclusion that international law does not yet recognize the ability to exercise this right against non-state actors. However, the Court’s avoidance of this issue in both instances may lead to the troubling conclusion that, where attacks by non-state actors cannot be attributed to the host state, the victim state simply lacks an inherent right of self-defense against armed attacks. The Wall and DRC opinions would seem to support this conclusion even where the host state is manifestly unable to address the threats emanating from its territory. Such a formulation results in a vacuum of accountability for armed attacks by cells operating within no-man’s-land pockets of a foreign state. Where the host state is unwilling or unable to address the situation, such an approach leaves the victim state with no viable options or remedies to address armed attacks. In response to this outcome, Judge Simma’s concurrence to the DRC opinion highlights the need for a more dynamic approach to the right of self-defense.[xvi] After pointing to the implications of Security Council Resolutions 1368 and 1373[xvii] and identifying the arbitrariness that would result from barring recognition of armed attacks solely on the basis of their non-attribution to a sovereign state,[xviii] Simma outlines the requirements of a recognized right against non-state actors so as to align with the traditional considerations—scale of initial attack, necessity, and proportionality—governing self-defense under Article 51 of the U.N. Charter.[xix] The United States has advocated a substantially similar approach to the issue. In highlighting Syria’s unwillingness or inability to address the threat posed by the Islamic State from within its territory, the United States specifies that it has accordingly “initiated necessary and proportionate military actions in Syria in order to eliminate the ongoing ISIL threat to Iraq.[xx]” Secretary General Ban Ki-moon’s statement of awareness that the air strikes “were not carried out at the direct request of the Syrian Government,” but that “the strikes took place in areas no longer under effective control of that Government”[xxi] indicates an acknowledgment of U.S. action in light of a state’s inability to address threats emanating from within. However, the extent to which this statement reflects a developing norm in favor of the U.S. position will depend upon other nations’ reactions to the current conflict in Syria and the clarity it might afford for future claims against non-state actors. In concluding, the need for a clearer standard of self-defense as a permissible response to armed attacks by non-state actors is illustrated by U.S. allies’ unwillingness to conduct airstrikes in Syria.[xxii] Their reluctance is understandable, particularly given the lack of direction provided by the ICJ on two separate occasions. However, even in the absence of a clearly defined rule, prior country statements and Security Council Resolutions should be sufficient to overcome this significant barrier to the development of a key area of international law. If the view is taken that “the credibility of the law depends ultimately upon its ability to address effectively the realities of contemporary threats,” as posited by many parties to the debate on self-defense,[xxiii] the realities of threats posed by non-state actors should be addressed.

[i] See Jeff A. Bovarnick et. al., Law of War Deskbook 35 (Brian J. Bill ed., 2010)  
[ii] See id.; see also Ryan Goodman, Australia, France, Netherlands Express Legal Reservations About Airstrikes in Syria, Just Security, Sept. 25, 2014,  
[iii] See Daniel Bethlehem, Self-Defense Against an Imminent or Actual Armed Attack by Nonstate Actors, 770 Am. J. Int’l L. 774 (2012).
  [iv] See Goodman, supra note ii.
  [v] S.C. Res. 1368, U.N. Doc. S/RES/1368 (Sept. 12, 2001).
  [vi] S.C. Res. 1373, U.N. Doc. S/RES/1373 (Sept. 28, 2001).
  [vii] Press Release, NATO, Statement by the North Atlantic Council (Sept. 12, 2001), available at
  [viii] See id.
  [ix] Bethlehem, supra note iii, at 772.
  [x] See Press Release, Security Council, Security Council Debates Escalating Crisis Between Israel, Lebanon; UN Officials Urge Restraint, Diplomacy, Protection of Civilians, U.N. Press Release SC/8776 (July 14, 2006).
  [xi] See Id.
  [xii] See Armed Activities on the Territory of the Congo (Dem. Rep. Congo v. Uganda), 2005 I.C.J. 168, ¶ 15 (Dec. 19) [hereinafter DRC Opinion] (separate opinion of Judge Simma).
  [xiii] See Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, 2004 I.C.J. 136, ¶ 115 (July 9) [hereinafter Wall Opinion].
  [xiv] See Wall Opinion, supra note xiii, at ¶ 139.
  [xv] See DRC Opinion, supra note xii, at  ¶ 146.
  [xvi] See DRC Opinion, supra note xii, at ¶¶ 8-11 (separate opinion of Judge Simma).
  [xvii] Id. at ¶ 11.
  [xviii] Id. at ¶ 12.
  [xix] Id. at ¶ 13.
  [xx] Representative of the U.S. to the United Nations, Letter dated Sept. 23, 2014 from Representative of the U.S. to the United Nations to the U.N. Secretary-General (Sept. 23, 2014), available at
  [xxi] U.N. Secretary-General Ban Ki-moon, Statement on U.S. Airstrikes in Syria (Sept. 23, 2014), available at
  [xxii] See Goodman, supra note ii.
  [xxiii] Bethlehem, supra note iii, at 773.