CNN reported on Aug. 1 that Retired Admiral William McRaven, the former Navy SEAL who led the Bin Laden raid, weighed in on President Donald Trump’s claim that he called off a strike at the last minute in response to the Iranian shootdown of an unmanned U.S. drone when he learned of the likely number of casualties. The New York Times editorial board reported in late June that Mr. Trump had concluded that the possible deaths of 150 Iranians “would not have been proportionate to the Iranian downing of a robotic spy plane.” Admiral McRaven indicated that it was hard to believe the President only learned of the casualty count just prior to the strike commencing, since “the casualty count is almost always part of the military’s briefing when it comes to a strike on a target.” Further, “this idea that it was only through the President’s restraint that we got as far as we did, I think the bigger question is: Why did we get that far?” However, Admiral McRaven is reported to have been ultimately happy with the President’s decision not to carry out the strikes, and he agreed it would not have been a proportionate response. As Newsweek indicated, Admiral McRaven “explained that the response to an incident like a drone shoot down should be a proportional strike, one that does not risk uncontrolled escalation.”
These comments over a month after the incident are of interest for a number of reasons. First, they highlight the now common practice by retired senior military officers to publicly critique the President’s national security processes and decisions. While Admiral McRaven expressed approval of this decision, the weight of this commentary has been far less favorable. This implicates the interface between the political and national security communities, highlighting the degree to which a rift has grown between a number of highly respected senior retired United States general/flag officers and their President regarding the use of military forces. For example, Retired General Stanley McChrystal is previously reported to have stated he believed President Trump was dishonest and immoral. This rift is obviously based on mistrust of the probity of the President’s statements. For those in the military community, both serving and retired, for whom honesty and honor are sacrosanct principles, these comments about the Commander in Chief are undoubtedly sobering.
Second, the statements by Admiral McRaven also shows the degree to which his views and that of the President are ultimately aligned (assuming the President’s rationale not to strike rested solely on a concern with proportionality). Their common ground centers on the issue of the proportionality of a defensive response to the use of force by an opposing State and the references to casualties in that analysis. This is noteworthy because there remains considerable disagreement amongst international lawyers regarding whether casualties, including civilian casualties, must be considered when assessing the proportionality of a State’s recourse to force in response to an armed attack (the jus ad bellum). Given the continuing tensions in the Gulf and the high stakes involved, the lack of consensus amongst international lawyers deserves closer analysis.
There are two legal schools of thought on this issue. One concentrates on blunting the military capability of the attacking State. Mike Schmitt has argued in a recent Just Security piece regarding this incident that
“a [jus ad bellum] proportionality analysis would focus on the scale and scope of the forceful response that would be required to deprive Iranian forces of the ability to launch the pending attacks and/or convince Iranian authorities to refrain from conducting them…. However, in making such an assessment, it is essential to understand that the issue would not be the possible casualties that might result, but rather the effect of the strikes upon continued Iranian attacks.”
Assessing civilian casualties would be a matter for international humanitarian law (IHL), not a component of the initial jus ad bellum analysis, which is a separate inquiry. Others support this approach, as is reflected in past commentary by Laurie Blank reported in the Washington Post that “[i]mportantly, this [jus ad bellum] rule of proportionality does not address civilian casualties. That is the task of the law of war principle of proportionality.”
The alternate method of assessing the legality of State action in self-defense considers not only the force used in the attack and the response, but also the damage and casualties that can result. This view has perhaps been most broadly stated by Judith Gardam in her 2004 book, Necessity, Proportionality and the Use of Force by States (p. 168), where she indicates the requirements of self-defense proportionality regulate the means and methods of warfare and targets, and must consider “the anticipated overall scale of civilian casualties, the level of destruction of enemy forces, and finally damage to territory, the infrastructure of the target State and the environment generally.” These competing views point to a fundamental divide within the international legal community regarding the role of proportionality when assessing a State action in self-defense.
Which viewpoint is right? Do the Iranian lives not count (literally) as a State makes decisions that can lead to broader conflict? Is the consideration of civilian casualties truly best left to IHL, the law governing the conduct of hostilities (jus in bello), alone and not considered under self-defense law? What effect does the law governing the State recourse to war have on the actual conduct of hostilities? As it turns out the issue of whether casualties, and in particular civilian casualties, have to be considered as part of a recourse to the use of force by States raises a number of questions about how the jus ad bellum and the jus in bello interact with one another. It also highlights that a traditional theoretical approach, which suggests these bodies of law operate separately from one another, does not reflect the reality of the practice of international law. Therefore, it will be helpful to look at the content of the self-defense “proportionality” rule and then address how the two bodies of law interact.
Jus ad Bellum Proportionality
So, what is assessed under jus ad bellum proportionality? The analysis is complicated by their common roots in Just War theory with both bodies of law relying on the principles of “necessity” and “proportionality,” although interpreted differently for each body of law. Notwithstanding the narrower approach that concentrates on weighing the counterforce applied in response to an armed attack, there are strong arguments supporting a wider assessment of jus ad bellum proportionality extending to the consideration of damage and casualties. The “roots” of this broader assessment can be found in the iconic 1837 Caroline Case with Daniel Webster’s reference “local authorities of Canada” having to establish they “did nothing unreasonable or excessive” in seizing and destroying a rebel ship, the Caroline, located in American waters.
A more contemporary reference to excessiveness is found in the 2005 Chatham House, Principles of International Law on the Use of Force by States in Self-defence, where Rule 5 states: “The force used, taken as a whole, must not be excessive in relation to the need to avert or bring the attack to an end,” but also that “[t]he physical and economic consequences of the force used must not be excessive in relation to the harm expected from the attack.” Yoram Dinstein states in his latest edition of War, Aggression and Self-defence that assessing self-defense proportionality in situations other than a “war” between States (i.e. in a more limited “on-the-spot reaction” or what he terms a “defensive armed reprisal”) involves a comparison by means of “a rough calculation of the acts of force and counter-force used, as well as the casualties and damage sustained.” (p. 282) Notably, no indication is made as to whether those casualties are limited to military personnel.
Another source of support for the position that casualties are part of the proportionality assessment in assessing the lawfulness of a State’s defensive response can be found in the 1996 International Court of Justice (ICJ) Nuclear Weapons Case, where it was ruled “a use of force that is proportionate under the law of self-defense, must, in order to be lawful, also meet the requirements of the law applicable in armed conflict which comprise in particular the principles and rules of humanitarian law.” (para. 42). The nature of nuclear weapons inevitably raises the issue of their potentially indiscriminate effect on civilians. According to the ICJ’s ruling, a determination that a use of such weapons is “illegal” due to the excessive incidental loss of civilian life, injury to civilians, or damage to civilian objects (Article 51(5)(b) of Additional Protocol I) would certainly be relevant to whether the State self-defense response itself was excessive. Importantly, even if their use was not viewed as being excessive under IHL it might still be considered so under the jus ad bellum. This is because the role of the jus ad bellum is different. Those restrictions are very much a product of the 20th Century inter-war effort to limit the recourse to war, which was at its heart “anti-war.” Certainly, IHL, such as the then relatively recent 1907 Hague Regulations, had done little to limit the ravages of World War I.
As the 17.7 million combatant and 39 million civilian deaths during World War II again established, States are capable of incredible violence. It may be that the past two decades of concentrating on drone strikes against non-State actors under an ongoing, if frequently controversial, self-defense envelope has resulted in an over emphasis being placed on the protections provided for civilians by humanitarian law to the exclusion of other important legal considerations. Perhaps one of the outcomes of States now focusing more on near peer, and peer to peer inter-State conflict, alongside ongoing conflicts against non-state actors, will be a deeper consideration by international lawyers of the broader role and principles of the jus ad bellum.
The Interaction Between Jus ad Bellum and Jus in Bello Proportionality
The interaction between proportionality, as assessed under IHL, and the test for State self-defense analyzed under the jus ad bellum can occur in a number of ways. Certainly, the consideration of “casualties,” and in particular civilian casualties, has arisen a posteriori. That is almost inevitable since for observers outside the military planning process it provides the most concrete evidence of the results of a decision to act. Jus ad bellum proportionality may also be assessed during the planning stages of a State response and throughout its execution. A State decision to contemplate the use force must come first, and in making and executing such a decision an interaction with IHL is inevitable.
As explained in the ICJ Oil Platforms Case, a strike by the United States against Iranian assets on April 14, 1988, which included attacks on oil platforms and the destruction of two Iranian frigates, occurred four days after an American warship struck a mine. During U.S. operational planning leading up to that strike, the targeting process would have identified military objectives, considered the military advantage to be gained from an attack and assessed the potential for collateral civilian casualties and damage. At the same time, the jus ad bellum proportionality assessment could and should have looked at those potential civilian casualties and damage as well as the impact on Iranian military personnel and materiel before striking. Although civilian casualties may be justified when weighed against the military advantage to be gained from attacking a military objective, they may not be necessarily in the context of limiting the recourse to war. This could lead to the consideration of other possible available targets that obtain the required effect without the same level of accompanying casualties or damage. The process can become interactive with the jus ad bellum proportionality consideration encompassing a broader range of factors that includes assessing the outcome of the IHL-based targeting process. It is noteworthy that in notifying the Security Council of its actions under Article 51 of the United Nations Charter the United States government stated: “All feasible measures have been taken to minimize the risk of civilian damage or casualties” (Oil Platforms Case, para. 67). Compliance with IHL obligations regarding potential civilian casualties was incorporated into self-defense reporting obligations.
Another area of controversy in the legal community has been the degree to which the law governing self-defense remains relevant once a decision to act is made. Again, it should come as no surprise there are two general approaches. The first is an “overarching” application of that law such that State defensive action is constrained by the principles of necessity and proportionality throughout the existence of a conflict. The second is a more “limited” theory where a distinction is made between traditional warfare between States, and isolated defensive exchanges and border skirmishes. It exempts significant armed conflict between States from the continued influence of the jus ad bellum after the conflict commences.
However, the divide between these two interpretations of international law is not as significant as might initially be believed. The “overarching” theory accepts that as a conflict expands in scope and intensity the law governing self-defense has a lessening influence (e.g. during total war, geographic restrictions on where hostilities occur would not be controlled by a proportionality assessment). And under the “limited” approach, minor exchanges not rising to the level of “war,” such as the recent one arising from the Iranian shoot down of an unarmed drone, fall well within the type of situation where the self-defense principle of proportionality would continue to govern State action.
Distinct from the debate among the “limited” and “overarching” theories of the jus ad bellum’s continued application during armed conflict, the interaction between these two bodies of law was the subject of vigorous debate in the development of the 1995 San Remo Manual on International Law Applicable to Armed Conflicts at Sea. Disagreement “centered on whether the principles of necessity and proportionality are applicable in a strategic sense only, or also on a tactical level [Rule 4, p. 77].” Application of the jus ad bellum at the tactical level could directly restrict the choice of targets and the methods and means of warfare, a clear IHL role. However, the ICRC Customary International Humanitarian Law study notes many States take the view in respect of targeting that “they will consider the military advantage to be anticipated from an attack as a whole and not from parts thereof” (Vol. I, Rule 8, p. 31), and the 1998 Rome Statute refers to the “overall military advantage anticipated” (Article 8(2)(b)(iv)). This suggests a strategic level assessment under IHL, which provides the space for an interaction between the two bodies of law at that level rather than the jus ad bellum having a direct tactical impact. It is at the strategic level that the law governing the State self-defesce response, and IHL, is best assessed.
Under the “strategic” approach described above, self-defense proportionality does not usurp the role of the law governing targeting, but it could still influence the boundaries of State action when acting in self-defense. The initial identification of lawful military objectives, the weapons used, and the assessment of expected civilian casualties and damage remain IHL issues. However, at the strategic level, the self-defense proportionality test may restrict which valid military objectives are struck, and the number of attacks. What remains under debate is whether the scale of anticipated civilian casualties affects whether those attacks take place at all, although clearly it is my view that it does. Added to this is the consideration of opposing military casualties. The self-defense test is different than, but not divorced from the IHL analysis.
Assessing Civilian Casualties in Jus ad Bellum Proportionality is the Right Approach
One point is both clear and notable: all voices on this issue strongly agree that excessive civilian risk resulting from an action in self defense necessitates the state forego or modify an attack, even if they might not agree on the phase at which that consideration produces that effect. However, given that the right to life is a deeply held principle in both war and peace; and the United Nations (UN) Charter, which articulates the State right to self-defense, was intended “to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind,” it is difficult to see how civilian casualties would not be relevant to the question of whether a State use of force is “proportional.”
The United States unquestionably carries a proverbial big stick. Admiral McRaven, who knows better than most the benefits and costs of wielding that stick, offers an important reminder on why it is often more prudent to follow President Roosevelt’s advice to speak “softly.” Indeed, the past two decades have clearly established, once the “dogs of war” are unleashed they are difficult to bring back to heel. A broad legal interpretation that accepts potential casualties have to be considered in determining the proportionality of a response to an armed attack ultimately seems more in tune with UN Charter history, its principles, and its goals. I believe the result is that by considering the potential for 150 Iranian casualties when determining the appropriateness of the response to the shootdown of the unmanned drone, the approach apparently taken by the United States President, those who advised him, and Retired Admiral McRaven is firmly grounded in law.