Shelly Aviv Yeini [*]
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In earlier times, before the start of battle, soldiers with swords in hand quietly waited for the order to attack. Regardless of whether they won or lost, opposing generals knew with certainty that fatalities and injuries would occur on both sides. With the development of technologically sophisticated and efficient defense systems, present-day armed attacks by less technologically advanced aggressors may result in no fatalities at all, but still trigger a defensive counterattack that results in a high number of casualties.
After the latest escalation of violence between Israel and Hamas in May 2021, it became very much clear that the parties to the conflict were not each other’s equals, most notably so due to Israel’s technologically sophisticated military capabilities. Such extreme asymmetry had much to do with Iron Dome, Israel’s efficient defense system.
Asymmetrical warfare is described as “a situation where an adversary can take advantage of its strengths or an opponent’s weaknesses.” An actor employs asymmetrical warfare to maintain its advantage in order to pursue its goals: “In the realm of military affairs and national security, asymmetry is acting, organizing, and thinking differently than opponents in order to maximize one’s own advantages, exploit an opponent’s weaknesses, attain the initiative, or gain greater freedom of action.”
Asymmetry increasingly characterizes modern warfare because of increasingly common armed conflicts between adversaries with vastly different military capabilities. The term “asymmetrical warfare” has been used “primarily in relation to the growing technological gap in conventional military capabilities between Western countries . . . and non-Western countries.” Indeed, while asymmetry can take different forms, its most notable dimension in modern conflict is technological asymmetry, “which occurs when one side of a conflict possesses superior weapon systems and other military equipment.”
Modern international law differentiates jus ad bellum from jus in bello. Jus ad bellum prohibits the use of force, with the exceptions of the right to self-defense and use of force under the auspices of the United Nations Security Council (“SC”). Jus in bello aims to balance the necessities of armed conflict with maintaining humanity by “setting clear limits on the conduct of military operations.” While asymmetry in technological advancements had arguably influenced jus in bello positively, as modern weapons are more precise and thus reduce collateral damage, such assessment becomes more complex with regard to jus ad bellum. For example, scholars point out that technological advancements in aircraft, including unmanned aerial vehicles, have made it easier for strong states in an asymmetrical conflict to attack with reduced danger of casualties.
Indeed, advanced air defense systems (“AADS”), which have a high success rate in intercepting rockets and missiles, have vastly increased the prevalence of asymmetrical warfare. The use of AADS has the potential to further increase the asymmetry of modern conflicts because the state that deploys it, even if it is heavily bombed, may protect its civilians from harm at an unprecedented rate.
The 2014 Gaza War saw the introduction of Israel’s AADS—Iron Dome. Despite adversaries launching approximately 4,000 missiles at the Israeli home front, the use of Iron Dome resulted in only six civilian casualties on the Israeli side, in stark contrast to the 2,251 Palestinians casualties resulting from Israeli attacks, of whom approximately 1,462 were civilians. While Iron Dome, a defensive system, did not inflict the Palestinian casualties itself, its success in defending Israel from missile and rockets attacks exacerbated the casualty asymmetry. The success of Iron Dome’s defensive capabilities thus served as the basis for many of the criticisms regarding Israel’s lack of jus ad bellum proportionality.
This Article examines whether the casualty asymmetry resulting from Israel’s use of Iron Dome is relevant to conceptions of proportionality under jus ad bellum theory. Such an examination is critical because a flawed analysis of proportionality may be both detrimental to the accused nation and easier for that nation to contradict. For example, if claims of disproportionality are based on a flawed understanding of the term, Israel may respond to the misuse of the term rather than honestly examine whether it has complied with the proportionality requirements of international law. Therefore, misuse of the term proportionality may hinder effective examination of compliance with international law’s proportionality requirements.
It should be noted that different classifications of the armed conflict might lead to different conclusions regarding the existence of Israel’s right to self-defense. For example, Dugard claimed that Israel’s actions during the 2014 Gaza War should “not be seen as an act of self-defense by a state subjected to acts of aggression by a foreign state or nonstate actor. Instead, it should be seen as the action of an occupying power aimed at maintaining its occupation.” Since this article discusses the effect of Iron Dome on the assessment of proportionality within the self-defense framework, such arguments, important as they are, will not be discussed here. The analysis focuses on sources accepting that Israel has a right of self-defense but criticizing it for lack of proportionality while acting in self-defense.
[*] Post-Doctoral Fellow, Hauser Global Fellows Program at NYU School of Law; Post-Doctoral Fellow, Minerva Center for the Rule of Law Under Extreme Conditions; Faculty of Law and Department of Geography and Environmental Studies, University of Haifa. I thank Eliav Lieblich for his valuable comments.
 Some scholars have long described the Israeli-Palestinian power balance as asymmetric due to differences in technological capabilities. See, e.g., Robert D. Sloane, Puzzles of Proportion and the Reasonable Military Commander: Reflections on the Law, Ethics, and Geopolitics of Proportionality, 6 Harv. Nat’l Sec. J. 299, 332 (2015). However, as this Article will demonstrate, Israel’s new defense mechanism has aggravated such asymmetry.
 Roger W. Barnett, Asymmetrical Warfare: Today’s Challenge to U.S. Military Power 15 (2003).
 Steven Metz & Douglas V. Johnson II, Asymmetry and U.S. Military Strategy: Definition, Background, and Strategic Concepts 5 (2001).
 See Laurie R. Blank, The Application of IHL in the Goldstone Report: A Critical Commentary, in 12 Y.B. Int’l Humanitarian L. 347, 355 (2009).
 Wyn Q. Bowen, The Dimensions of Asymmetric Warfare, in The Changing Face of Military Power 15, 15 (Andrew Dorman ed., 2002).
 See Metz & Johnson II, supra note 3, at 5–6 (“[Asymmetrical warfare] can be political-strategic, military-strategic, operational, or a combination of these. It can entail different methods, technologies, values, organizations, time perspectives, or some combination of these.”).
 Michael N. Schmitt, Asymmetrical Warfare and International Humanitarian Law, 62 A.F. L. Rev. 1, 5 (2008).
 U.N. Charter art. 2, ¶ 4.
 Id. at art. 51.
 Jasmine Moussa, Can Jus ad Bellum Override Jus in Bello? Reaffirming the Separation of the Two Bodies of Law, 90 Int’l Rev. Red Cross 963, 965 (2008).
 See Martin L. Cook & Mark Conversino, Asymmetric Air War: Ethical Implications, in The Moral Dimension Of Asymmetrical Warfare 47, 50 (Th. A. van Baarda & D.E.M. Verweij eds., 2009) (“This great success on the jus in bello side of things produced an unanticipated effect on the jus ad bellum side of the equation.”). Not all commentators agree that asymmetrical warfare has positive effects in jus in bello. See, e.g., Suzy Killmister, Remote Weaponry: The Ethical Implications, 25 J. Applied Phil. 121, 122 (2008) (asserting that asymmetrical warfare pushes weak parties to violate their in bello obligations in order to have a standing chance in the armed conflict).
 See Cook & Conversino, supra note 12, at 50 (“Political leaders who, prior to development of these technologies, would have thought long and hard about going to the military instrument of national power . . . now were tempted to reach for it more quickly and with less weighty deliberation.”); Bradley J. Strawser, Moral Predators: The Duty to Employ Uninhabited Aerial Vehicles, 9 J. Mil. Ethics 342, 358 (2010) (“The worry here is that the asymmetry in combat abilities created by the advanced technology of UAVs . . . makes it too easy for the nation employing UAVs to go to war. That is, the asymmetry created by UAVs lowers the jus ad bellum threshold such that more unjust wars might be conducted because the risks of war to a nation-state could become so minimal.”); id. at 359 (“The scope of this issue . . . strikes at any asymmetry in military technological development whatsoever.”).
 Iron Dome is part of Israel’s multi-tiered missile defense system, which also includes Arrow 2, Arrow 3, Iron Beam, Barak 8, and David’s Sling. However, Iron Dome is the most dominant AADS due its interception success rate. See Daphné Richemond-Barak & Ayal Feinberg, The Irony of the Iron Dome: Intelligent Defense Systems, Law, and Security, 7 Harv. Nat’l Sec. J. 469, 495 (2016).
 Rep. of the Detailed Findings of the Indep. Comm’n of Inquiry Established Pursuant to Human Rights Council Resolution S-21/1, ¶ 574, U.N. Doc. A/HRC/29/CRP.4 (June 24, 2015) [hereinafter Indep. Comm’n of Inquiry]. Israel has asserted that 761 of the casualties were civilians rather than 1,462. State of Israel, The 2014 Gaza Conflict: Factual and Legal Aspects 2 (2015).
 This article operates under the assumption that Israel had a right of self-defense in the 2014 and 2021 conflicts and examines the disagreement over whether it exercised proportionality in exercising that right. Some scholars have concluded that Israel did not have a right to self-defense in 2014 or in other conflicts. See, e.g., John Dugard, Debunking Israel’s Self-defense Argument, Aljazeera America (July 31, 2014), http://america.aljazeera.com/opinions/2014/7/gaza-israel-internationalpoliticsunicc.html [https://perma.cc/M7N5-R8N9] (stating that Israel’s actions during the 2014 Gaza War should “not be seen as an act of self-defense by a state subjected to acts of aggression by a foreign state or nonstate actor. Instead, [they] should be seen as the action of an occupying power aimed at maintaining its occupation”); see also Sharon Weill & Valentina Azarova, The 2014 Gaza War: Reflections on Jus ad Bellum, Jus in Bello, and Accountability, in The War Report: Armed Conflict in 2014 360, 367–68 (Annyssa Bellal ed., 2015). Such arguments, as important as they are, are outside of the scope of this analysis.
 Dugard, supra note 16; see also Weill & Azarova, supra note 16, at 367–68.
 Judith Gardam, Necessity, Proportionality and the Use of Force by States 33 (2004) (“The concept of proportionality was an integral component of just war theory. […] Once that judgment was made, the conduct of war was of secondary concern.”).