Introduction
In 2015, a targeted attack by a British drone killed two Britons and one Belgian in Syria. The British government believed that one of these individuals was conspiring to conduct terrorist violence within the United Kingdom. Footnote 1 The government’s “precision air strike” precipitated significant consideration as to its legality, including a UK parliamentary report in April 2016 labelling the strike a “targeted killing.” Footnote 2 “Targeted killing” is the term used to describe “the intentional, premeditated and deliberate use of lethal force, by States or their agents acting under colour of law, or by an organized armed group in armed conflict, against a specific individual who is not in the physical custody of the perpetrator.” Footnote 3 The United Kingdom is not the only state to confront legal issues arising out of targeted killing as a tool of counter-terrorism. Footnote 4 Famously, the United States’ large-scale drone aircraft campaign, first leveraged against Al-Qaeda and now against other threats, has precipitated considerable controversy, written construals of the applicable legal standards authored by the Obama administration, Footnote 5 and a massive law review literature evaluating US conduct. Footnote 6
In Israel, the state’s policy of targeted killing resulted in an important decision from that country’s high court, to date the most detailed judicial consideration of the question. Footnote 7 In comparison, within Canada, there has been no sustained public discussion of the lawfulness of targeted killing, let alone the targeted killing of a Canadian national. Footnote 8 The British experience suggests, however, that Canada may confront acute dilemmas in the near future. Canadians have participated in foreign civil conflicts before — including, most famously, in the Spanish Civil War. But, for the first time, a significant number of Canadians are travelling abroad to participate in foreign insurgencies and terrorist groups — including Daesh, Al-Qaeda, and Al-Shabaab — that actively encourage terrorist attacks on Canadians and Canada. Footnote 9 Canada is, in fact, involved in an armed conflict with one of these entities — Daesh — in Iraq and Syria. And, so, for the first time since the introduction of the Canadian Charter of Rights and Freedoms (Charter), the Canadian government may ask its soldiers to target and kill fellow Canadians abroad or to assist allies in doing so. Footnote 10
The increase in Canadian foreign fighting with terrorist groups and Canada’s participation in the anti-Daesh military campaign thus raises a host of novel legal issues, including the question of targeted killing that was confronted by the United Kingdom in 2015. We take the view that these legal questions are no longer purely academic and are best discussed publicly in advance rather than resolved retroactively to accommodate operational events. Moreover, the (limited) legal analysis on the topic of targeted killing released to date by other states is typically a blend of domestic and international legal concepts, Footnote 11 sometimes hybridized in a manner that creates a sense of false certainty and masks the choices made in areas where there is legal doubt. Not least, in describing their legal position after the 2015 strikes, British government officials articulated views that were internally inconsistent. Key among them were positions on, among other things, the relative scope of international humanitarian and international human rights law. Footnote 12
For all of these reasons, it would be both undesirable and imprudent for Canada to rely simply on the legal reasoning of other states in devising its own legal position on this contentious issue. This article analyzes, therefore, the legal implications surrounding the targeted killing by the Canadian government of Canadian citizens abroad. To reach this objective, it wrestles with issues of international and Canadian public law whose precise parameters are contested, and yet the construal of which may affect the fate of both those targeted and those doing the targeting. We do not believe that all of these legal issues can presently be resolved definitively. Legal advice on the relevant international law would necessarily be provisional and would, in practice, amount to a policy choice. Since the domestic legal ramifications of targeted killing would be coloured by this uncertain international law, domestic legal opinions would also be far from definitive. The purpose of this article, therefore, is not to opine definitively on the legality of a Canadian targeted killing or to consider its wisdom from a policy perspective. Instead, its intent is to suggest, and, indeed, to map, how a Canadian policy of targeted killing would oblige Canada to make conscious policy choices on several weighty matters of international law. These international law issues would, in turn, directly affect the legality of government conduct under Canadian public law.
We divide the article into five sections. In the first section, we define the factual parameters giving rise to new legal dilemmas. Footnote 13 Specifically, we explore the phenomena of “foreign fighting,” counter-terrorism, and the circumstances of the armed conflict with Daesh as well as other instances of foreign terrorist fighting. In the second section, we examine the Canadian public law rules that apply when the Canadian Armed Forces (CAF) deploy in armed conflicts overseas. The third section examines international law governing military force, scrutinized from the perspective of the use of force (jus ad bellum) and the law of armed conflict (jus in bello). In the fourth section, we focus on an alternative body of international law: that governing peacetime uses of lethal force. Finally, in the fifth section, we weave together these areas of law into a single set of legal questions that would necessarily have to be addressed prior to the targeted killing of a Canadian.
Foreign Fighting, Counter-Terrorism, and the Daesh Armed Conflict
This article focuses on the most complex form of targeted killing: a targeted killing by Canada of a Canadian national abroad, either directly or in cooperation with allied forces. By necessity, therefore, our focus is on a sub-category of “foreign fighters.” Foreign fighting is a persistent international phenomenon that defies easy classification. A “foreign fighter” is “an intermediate actor category lost between local rebels, on the one hand, and international terrorists, on the other.” Footnote 14 For the purposes of this article, we follow Thomas Hegghammer in describing a foreign fighter as one who “(1) has joined, and operates within the confines of, an insurgency, (2) lacks citizenship of the conflict state or kinship links to its warring factions, (3) lacks affiliation to an official military organization, and (4) is unpaid.” Footnote 15
foreign fighting and international law
Despite its prevalence, foreign fighting is a colloquial, rather than a legal, concept. Certainly, in Resolution 2178 (2014), the UN Security Council (UNSC) responded to the rise of Daesh in Iraq and Syria by requiring states to restrict, among other things, travel by individuals who aim to become “foreign terrorist fighters.” Footnote 16 Subsequently, in Resolution 2249 (2015), the UNSC (obliquely) suggested that states might use force against Daesh in Iraq and Syria, without clearly authorizing such use. Footnote 17 However, there is no separate set of legal rules applicable to “foreign fighters” that places them on a distinct legal footing from conventional armed forces or unconventional militia, guerrilla, or rebel-type insurgent forces.
In fact, foreign fighters, including Canadians, participate in either formal armed conflicts — a critical concept defined later in this article — or acts of terrorism that fall short of armed conflicts. Examples of the latter, “peacetime” foreign fighters are the two Canadian men who died in a 2013 Al-Qaeda-linked terrorist attack that killed as many as sixty individuals at an Algerian gas plant. Footnote 18 Canadian foreign fighters also participate in more clearly defined intra-state armed conflicts. For instance, in 2013, a Canadian fighting with an armed insurgency (and terrorist group) Al-Shabaab reportedly participated in a deadly attack in Mogadishu. Footnote 19 Intelligence estimates from several years ago suggest as many as twenty Canadians have joined the terrorist group in Somalia. Most notoriously, in 2009, six young Somali Canadians left Toronto to fight in the organization. At least four of them were killed. Two others reportedly became disillusioned and left the terrorist group but remained in Somalia. Footnote 20
Other Canadians have joined Daesh in Syria and Iraq (and possibly in other places such as Bangladesh), and it is the siren call of this group that is the most alarming development. It is difficult to know how many Canadians have already joined Daesh and other terrorist groups — there has been no public accounting by the Canadian government. To be sure, Canadians make up a small percentage of this global foreign terrorist fighter phenomenon. However, on a per capita basis, more Canadians than Americans have travelled abroad to join Daesh. Footnote 21 In February 2016, the government was aware of more than 180 individuals with Canadian connections who were abroad and suspected of engaging in terrorism-related activities, more than half of whom were believed to be in Iraq, Syria, or Turkey. Another sixty had returned home. Footnote 22 Earlier, in October 2014, the Royal Canadian Mounted Police (RCMP) was reportedly tracking ninety individuals who intended to travel, or had returned from overseas, although it is not clear how many of these were affiliated with Daesh. Footnote 23
Canadian foreign fighters come from across the country. A recent study conducted by Lorne Dawson, Amaranath Amarasingnam, and Alexandra Bain interviewed forty foreign fighters involved in the conflict in Syria and Iraq. In the course of this research, it became “evident that Canadian foreign fighters have been leaving in fairly distinct clusters, reflecting a pattern of mutual or collective radicalization amongst small groups of largely young men. Such clusters have been traced in Calgary, Edmonton, Ottawa, Toronto, and Montreal.” Footnote 24 As this article is written, some reports suggest that the flow of foreign fighters into Iraq and Syria has waned. Footnote 25 On the other hand, terrorist attacks outside of Syria and Iraq directed or inspired by Daesh are increasing. As discussed next, this is a development consistent with the traditional security fears sparked by foreign fighting.
the threat posed by foreign fighters
Foreign fighting has become an urgent matter for many governments that are far from the areas in which these groups typically operate because of the (often presumed) association between foreign fighting and international terrorism. Specifically, many of the current concerns about foreign fighters reflect preoccupations with the return of fighters to their countries of nationality. This “return” preoccupation can be summarized by the following statement: even though some of the foreign fighters “may not return as terrorists to their respective countries ... all of them will have been exposed to an environment of sustained radicalization and violence with unknowable, but worrying, consequences.” Footnote 26 Put another way, fears “center around the threat of a ‘bleed out’ as jihadi veterans, equipped with new knowledge of fighting, training, recruitment, media and technical skills in building bombs, take their skills elsewhere — potentially facilitating the initiation or escalation of terrorism in their home country or in other arenas, and enhancing the power of insurgencies and terrorist groups.” Footnote 27
Canadian government officials quite rightly regard many of the groups with whom Canadian foreign fighters have associated as security risks. In 2002, an Al-Qaeda recording singled out Canada — along with France, Italy, Germany, and Australia — for allying itself “with America to attack us in Afghanistan.” The speaker — likely Osama bin Laden — asserted “as you kill you will be killed and as you bomb you will be bombed.” Footnote 28 Canadian officials have since pointed often to this statement — and a follow-up issued in 2005 — when describing the terrorist threat to Canada. Footnote 29 For its part, the Somali terrorist group Al-Shabaab has attacked people in Uganda for watching football games and targeted courthouses and other venues in Somalia. Most famously, it killed sixty-three innocent shoppers in the Westgate Mall in Nairobi, Kenya, and 147 innocent students at Kenya’s Garissa University. It also called for terrorist attacks in Canada in February 2015. The video called “upon our Muslim brothers, particularly those in the West, to answer the call of Allah and target disbelievers wherever they are … what if such an attack was to occur in the Mall of America in Minnesota? Or the West Edmonton Mall in Canada? Or in London’s Oxford Street?” Footnote 30
Daesh’s terrorist ambitions in regions far outside of Iraq and Syria are now clear. Moreover, of all of these groups, Daesh is the only one with whom Canada is plainly involved in an armed conflict. In late October 2014, Canada joined the American-led coalition against Daesh in Iraq. The government reported to the UNSC that Canada was invoking individual and collective self-defence under Article 51 of the Charter of the United Nations (UN Charter), explaining that “[s]tates must be able to act in self-defence when the Government of the State where a threat is located is unwilling or unable to prevent attacks emanating from its territory.” Footnote 31 In total, 600 military personnel were deployed as part of Joint Task Force Iraq, and six CF-18 fighter aircraft supported the coalition in the conduct of airstrikes against Daesh forces, infrastructure, and equipment. Footnote 32 Another sixty-nine armed forces personnel worked in an advisory and assistance role providing strategic and tactical advice to Iraqi security forces. Footnote 33 In March 2015, the deployment was extended for a year and expanded to include Daesh targets in Syria. Under the Trudeau government, the mission, dubbed “Operation Impact,” was extended until 31 March 2017 and refocused on providing training and assistance to Iraqi security forces. Canadian CF-18 fighter aircraft ceased conducting airstrikes on 15 February 2016, but Canadian reconnaissance and refuelling aircraft continued to support coalition air operations. Footnote 34 At the time of writing, Canadian troops also continue to identify and mark targets for coalition strikes. Footnote 35
foreign fighting and targeted killing
Given this factual context, it is possible, if not likely, that Canada will be faced with the question of whether to use lethal force against a Canadian foreign fighter associated with one or more of these terrorist groups abroad. That occasion may arise either directly — the CAF targets the Canadian — or indirectly — Canadian officials intentionally aid and assist an ally in the targeting, resulting in a strike mounted by that ally. Either way, similar complicated legal issues arise. Footnote 36 From an international law perspective, those legal issues bifurcate depending on the precise circumstances of the targeted killing. The most perilous prospect is a targeted killing outside of an armed conflict, involving peacetime use of lethal force. The least fraught circumstance is one in which the killing occurs within an armed conflict in which Canada is a party and the Canadian target is taking a direct part in the hostilities. Even here, however, a determination of the legality of that killing hinges on a cascade of legal questions.
How a targeted killing of a Canadian abroad would be assessed in domestic law is even more uncertain. Accordingly, in the next section, we begin our analysis by examining the domestic legal standards that, while woefully underdeveloped, do exist. It is ultimately our position that international law should be the reference point when interpreting these Canadian standards. As such, in the third section of this article, we canvass the international law that would apply should Canada wish to advance the argument that its use of force was compliant with the legal norms on use of force and armed conflicts. In the fourth section, we examine international law and the use of lethal force in a peacetime context.
Canadian Public Law and the Militarization of Anti-terrorism
The Canadian executive has the competency to order the CAF to kill a Canadian foreign fighter abroad. A decision to deploy the CAF to perform its military functions is made exclusively by the executive branch as an exercise of the royal prerogative. Footnote 37 The domestic law governing the lawfulness of this order stems from a variety of sources. In this article, we focus briefly on criminal and constitutional law standards, as these are likely engaged by any prospective targeted killing.
criminal law
Canada is a party to the Geneva Conventions and their Additional Protocols. Footnote 38 These instruments, discussed below, and their customary analogues comprise the core of international humanitarian law (IHL), often referred to by service members as the law of armed conflict (LOAC). The actions of CAF members deployed internationally are governed by LOAC and the CAF’s Code of Conduct, which operationalizes the rules of IHL. Footnote 39 The Geneva Conventions and the Additional Protocols are made part of the law of Canada by the Geneva Conventions Act, which makes grave breaches of the Geneva Conventions and Additional Protocol I, such as wilful killing or torture, a crime prosecutable in Canada. Footnote 40 Parliament has also enacted the War Crimes and Crimes against Humanity Act, anticipating prosecutions for war crimes occurring both within and outside Canada. Footnote 41
Moreover, the general territorial limits of Canada’s criminal law do not apply to CAF members deployed overseas. Footnote 42 This means that convictions may be entered against CAF members who violate Canada’s criminal law abroad. For this reason, a CAF member committing a crime while deployed internationally is most likely to be charged with a conventional Criminal Code offence — such as murder — and face court martial under the Code of Service Discipline. Footnote 43 This code is enacted in Part III of the National Defence Act (NDA) and, among other things, imposes regular Canadian criminal law on CAF members, prosecutable before civilian or military courts. Footnote 44 A relatively recent example is the court martial of Army Captain Robert Semrau in 2010 for allegedly shooting a wounded Afghan on the battlefield. Semrau faced four charges under the NDA, including two under section 130, which stipulates that an “act or omission” is an offence “that takes place outside Canada and would, if it had taken place in Canada, be punishable under Part VII, the Criminal Code or any other Act of Parliament.” Footnote 45 Semrau was acquitted of second-degree murder and attempt to commit murder using a firearm as defined under section 235(1) and section 239(1)(a)(i) of the Criminal Code.
Soldiers are, of course, expected to engage and kill lawful targets in a theatre of war. Canadian criminal law does not include any emphatic “combatant’s privilege” analogous to the principle applied in international humanitarian law, discussed below. However, in the (unlikely) event that prosecutors bring charges following an internationally lawful use of military force, certain defences would probably be available. First, the Criminal Code preserves common law defences — that is, “every rule and principle of the common law that renders any circumstance a justification or excuse for an act or a defence to a charge.” Footnote 46 Since a combatant’s privilege exists as part of customary international humanitarian law (for, at least, international armed conflicts) and since customary international law is part of the common law of Canada, Footnote 47 a common law defence to otherwise criminal conduct undertaken in a time of armed conflict may exist. Second, Canadian law includes a defence of “necessity” — that is, an excuse for non-compliance with the criminal law “in emergency situations where normal human instincts, whether of self-preservation or of altruism, overwhelmingly impel disobedience.” Footnote 48 The defence is available “in urgent situations of clear and imminent peril” Footnote 49 and not as part of a premeditated policy outside of this context. Footnote 50 Compliance with the law must also be “demonstrably impossible.” Footnote 51 Finally, there must be proportionality “between the harm inflicted and the harm avoided.” Footnote 52 Third, the Criminal Code contains a more conventional self-defence provision, exonerating a person who acts reasonably in self-defence to protect themselves or a third person from a use or threat of force. Footnote 53
constitutional law
The Charter guarantees, among other things, “the right to life, liberty and security of the person and the right not to be deprived thereof except in accordance with the principles of fundamental justice.” Footnote 54 This section 7 right reaches maltreatment causally tied to the conduct of the Canadian state. Footnote 55 While the courts have never had to decide the matter directly, a targeted killing almost certainly would engage the right to life. Footnote 56 Its lawfulness would depend, therefore, on whether the Charter reached a targeted killing conducted overseas and, if so, whether that killing was inconsistent with section 7’s guarantee and with section 1 of the Charter.
Charter’s Extraterritorial Reach
Whether Canadian constitutional obligations follow the CAF overseas is an uncertain issue at present. The starting point in understanding the extraterritorial reach of the Charter is the Supreme Court of Canada’s decision in R v Hape. Footnote 57 In this matter, the RCMP conducted an overseas criminal investigation with the express consent of the foreign authorities and in partnership with them. Justice Louis LeBel, writing for a majority of the Court, looked to international law and the principle of the comity of nations to construe the reach of the Charter. The Court held that section 8 of the Charter did not reach the RCMP’s conduct in this context. He reasoned that the extension of section 8 extraterritorially without the consent of the territorial state would be an intrusive invasion of state sovereignty and would necessarily “entail an exercise of the enforcement jurisdiction that lies at the heart of territoriality.” Footnote 58
However, the Supreme Court of Canada, in obiter, included a caveat: the Charter could reach overseas conduct by a Canadian agency where compliance with Canada’s international obligations was at issue: “The principle of comity does not offer a rationale for condoning another state’s breach of international law.” Footnote 59 The Court has since commented on this Hape exception: “[T]he Court was united on the principle that comity cannot be used to justify Canadian participation in activities of a foreign state or its agents that are contrary to Canada’s international obligations.” Footnote 60 Since then, the Supreme Court of Canada has applied the Hape exception to extend the Charter overseas where Canadian state actors are in violation of Canada’s international human rights obligations. Footnote 61 Adding considerable confusion to this jurisprudence, the federal courts have confined the reach of this Hape exception to circumstances where the victim of the international human rights wrong was a Canadian citizen. Footnote 62 And, in fact, the Federal Court of Appeal declined to apply the Charter to detainee transfer practices employed by the CAF in Afghanistan. Footnote 63 However, that case hinged in large measure on the foreign nationality of the Afghan detainees — it should not be read as a general bar on the application of the Charter to extraterritorial Canadian military conduct jeopardizing a Canadian citizen’s rights. Footnote 64
It is also notable that nothing in the Hape dicta confines its exception strictly to violations of international human rights norms. In Khadr v Canada, the Court concluded that Canada was in violation of the Geneva Conventions and “that participation in the Guantanamo Bay process which violates these international instruments would be contrary to Canada’s binding international obligations.” Footnote 65 As noted, the Geneva Conventions are international humanitarian law, a branch of international law distinct from international human rights law. Given that the Supreme Court of Canada has already reached beyond human rights law to identify circumstances that trigger the Hape exception, it might reasonably follow that violating a foreign state’s sovereignty (a breach of Canada’s international obligations) could also implicate the Charter’s extraterritorial dimension.
Indeed, the Supreme Court of Canada’s holding in Hape created unexpected murkiness on this question. In a puzzling exegesis, it implied without any reference to positive law that the exercise of “enforcement jurisdiction” — that is, enforcing Canada’s laws on the territory of another state — without the consent of the territorial state will be beyond the legal competency of any Canadian agency, Footnote 66 regardless of whether that conduct is authorized by the legislation: “Neither Parliament nor the provincial legislatures have the power to authorize the enforcement of Canada’s laws over matters in the exclusive territorial jurisdiction of another state.” Footnote 67 We discuss the issue of enforcement jurisdiction in the next section.
The Scope of the Charter’s Protection
Should the Charter apply, the question of whether a targeted killing complies with it becomes acute. The right to life in section 7 is not absolute. Rather the Charter guards against deprivations that are not in accordance with “principles of fundamental justice.” Exactly what this means in the targeted killing context is unknown. But of obvious relevance is the line of cases holding that the use of lethal force by police officers “constitutes a prima facie breach of s. 7 of the Charter.” Footnote 68 Moreover, since in other contexts, the scope of Charter rights has been assessed with an eye to international law standards, it is plausible that a targeted killing done in violation of international law would also transgress section 7. Footnote 69
Whether this conduct could then be justified as a reasonable limitation on the Charter right under section 1 would hinge on the facts. Under the Oakes test, section 1 may exonerate rights-impairing conduct where the government proves that the measure has an important objective: that there is a rational connection between the objective and the means, that there is a minimal impairment of the right in question, and that there is proportionality between the impact on the right and the benefits of the measure in question. Footnote 70 It seems likely that the proportionality criterion would be a (if not the) key consideration in relation to any targeted killing. Although not necessarily doing so as part of a formal section 1 discussion, courts have focused on “principles of proportionality, necessity and reasonableness” in cases implicating allegations of excessive use of force by police. Footnote 71
We suspect that in a targeted killing context, bona fide exigency in staving off a terrorist attack may be enough to satisfy these standards. We also hazard that the government’s case would become more difficult, especially in relation to the proportionality test, the more hypothetical, less immediate, and less dire the risk posed by the target. Footnote 72 An obvious question in the British 2015 incident, for example, is whether other means could have been pursued to stop a terrorist attack in the United Kingdom engineered from distant Syria. Imminence, necessity, and proportionality, therefore, become important questions. As we discuss below, these concepts also drive much of the international law in this area. The bottom line from this discussion is that Canada’s domestic legal standards — whether in terms of prospective criminal culpability or constitutionality — may well end up being indexed to international law. And so addressing the standards applicable to a Canadian targeted killing abroad obliges a review of just when, exactly, a CAF targeted killing operation would satisfy international law.
International Law of Militarized Counter-Terrorism
The international lawfulness of a targeted killing must be scrutinized with reference to two different categories of law: the law that governs a state’s use and scope of military force in a conflict and the law that governs a state’s use of lethal force in other circumstances. In this section, we focus on the first category — international law applicable to military force in an armed conflict. International law on the use of military power is divided into two broad categories. Both categories include doctrines relating to the scope and scale of military force, but, speaking generally, use-of-force rules — known more classically as jus ad bellum — determine when recourse to military force is lawful. The laws of armed conflict — jus in bello — determine what type of military force is lawful and contain more specific rules on, for instance, who can be targeted. Both of these areas of law developed in response to classic inter-state conflicts. While today’s insurgencies and militarized counter-terrorism campaigns place serious interpretative strain on the applicable rules, it remains true that any legal justification of a targeted killing as a legitimate use of military force would need to meet both the jus ad bellum and jus in bello standards.
use of force and counter-terrorism
Article 2(4) of the UN Charter constitutes the core of the modern law on the use of force. It specifies that “[a]ll Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.” Footnote 73 The rule exists also as customary international law, Footnote 74 and commentators widely regard it as a jus cogens norm. Footnote 75 Debate occasionally arises as to the reach of Article 2(4) and its customary equivalent. The rule might be parsed in quest of a use of force that does not impair the “territorial integrity or political independence of any state.” Footnote 76 Practically, it is difficult to imagine any non-consensual use of force that falls short of this impairment standard. The very act of using force without the consent of the territorial state is inconsistent with a state’s sovereign control over affairs within its borders Footnote 77 and is “inconsistent with the Purposes of the United Nations.” Footnote 78 There are, however, supplemental threshold issues that deserve further inquiry. First, in what circumstance does an act of violence constitute a “use of force”? Second, there is an attribution issue: does use-of-force law permit military violence directed at a non-state actor located on the territory of a state that is unwilling or unable to forestall the violent conduct of that non-state actor? We deal with the first question in the next section and the second question below.
Meaning of “Force”
If the coercion visited by one state on another does not reach the threat or use of force, it is not governed by Article 2(4) and, absent some other restraint in international law, is lawful. Some covert actions undertaken by states may impinge, for instance, on the sovereignty interests of other states but fall short of the use of force. Footnote 79 Thus, economic coercion or intervention are not uses of force. Footnote 80 Likewise, the training and equipping of groups conducting acts of armed violence against another state is a use of force, but “the mere supply of funds” to them is not. Footnote 81 The intrusion of armed forces onto the territory of another state in the absence of armed coercion is likely also not a use of force. Footnote 82 The deployment of troops for surveillance purposes is one example that would conceivably fall short of an Article 2(4) violation. However, the question of whether low-intensity uses of actual military violence may fall below the use-of-force threshold is hotly debated and, thus, is a key question for militarized counter-terrorism.
There is some support for the existence of a de minimis intensity or gravity threshold for “force.” Without any true analysis, the European Union’s independent international fact-finding mission on the conflict in Georgia recorded a view in a footnote that some military incidents could fall below this threshold, such as “the targeted killing of single individuals, forcible abductions of individual persons, or the interception of a single aircraft.” Footnote 83 If this approach is correct, it necessarily raises a question as to the degree of violent coercion required before the conduct graduates to “force.” Here, terminology proliferates. For instance, while Article 2(4) “is applicable to any military operations conducted by one state against another,” Olivier Corten concludes that military force is distinguishable from “a simple police measure.” Footnote 84 However, the breadth of the latter, colloquial concept raises its own doubts. A targeted, surgical forcible abduction may be regarded as a police measure. Footnote 85 But if the forcible abduction implicates a more massive military presence, then its gravity as a coercive act increases — and, therefore, so too the prospect that it is “force.” Again, however, there is no clear litmus test for this transformation from police act to military force. Footnote 86 Corten concludes that the threshold is more likely crossed where, among other things, the military coercion is directed at another state rather than at a non-state actor. Footnote 87 If so, such criteria may have the effect of potentially excluding the applicability of Article 2(4) to certain targeted killings directed at, for instance, terrorist groups located in the territory of another state.
Other commentators, however, have resisted this approach and the very idea of a de minimis threshold for the use of force. The counter-position (probably most commonplace among international scholars) is that “no specific gravity threshold can be read into Art. 2(4) UN Charter nor be shown to exist in the customary practice of States.” Footnote 88 On the topic of targeted killings, Tom Ruys argues:
[W]henever one state deliberately sends military or police forces into the territory of another (without the latter’s authorization) to take forcible action, the international relations between those states (in the sense of Article 2(4)) are necessarily affected. This finding remains valid even though the targets in question are private individuals, not state organs, even if the private individuals do not have the nationality of the territorial state in which the operation takes place, and even if no actual damage is done to state infrastructure. Footnote 89
He also notes (correctly) that the de minimis concept depends on the state on whose territory the armed intervention takes place, opting for passivity in the face of conduct that might otherwise reasonably be expected to precipitate a clash. Footnote 90 Put another way, the characterization of “use of force” proffered by defenders of a de minimis theory depends on the territorial state’s response (or knowledge of the incursion), not on the nature of the intervening state’s conduct. This is an unhelpfully contingent manner of establishing a legal threshold.
More than this, there is no compelling state practice situating targeted killing in a different category than other forms of military action for the purposes of Article 2(4). Canvassing incidents, Ruys concludes that “one can reasonably infer that the claim that targeted operations are, as such, outside the scope of UN Charter Article 2(4) does not correspond to state practice.” Footnote 91 He also asserts “any deliberate projection of lethal force onto the territory of another state — even if small-scale and even if not targeting the state itself — will normally trigger Article 2(4). The characterization of such operations as a use of force is not contingent on whether they result in actual armed confrontations with the territorial state.” Footnote 92
Exceptions to Article 2(4)
Even where it applies, there are limited exceptions to the prohibition found in Article 2(4). For one thing, use of force by one state within the territory of another is permissible where the territorial state gives its permission. Otherwise, use of force directed by one state against another is permissible in international law in only two circumstances, both expressly anticipated by the UN Charter. First, pursuant to Chapter VII of the UN Charter, the UNSC may legitimize and authorize the use of force. Second, the UN Charter also acknowledges (but does not itself create or define) an inherent right to self-defence.
Since the UNSC has not clearly authorized the use of force as a form of counter-terrorism under Chapter VII, we focus in this article on self-defence. Footnote 93 Article 51 of the UN Charter preserves “the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security.” As the reference to “inherent right” suggests, the self-defence concept is part of customary international law, although the precise relationship between the customary norm and Article 51 is a point of some controversy. Footnote 94 Certainly, in all cases, the act of self-defence must meet the classic customary requirements of being both proportional and necessary. Footnote 95 Recently, the more controversial question is that of “armed attack” and imminence — that is, whether the defending state must actually have suffered the blow of the “armed attack” before responding. The issues of “armed attack,” necessity, proportionality, and imminence are discussed in turn below.
Armed Attack
As with “use of force,” the concept of “armed attack” prompts its own difficult questions of definition. Not every use of force is an armed attack. In Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America), the International Court of Justice (ICJ) distinguished (obliquely) between “the most grave forms of the use of force (those constituting an armed attack) from other less grave forms.” Footnote 96 It focused on the “scale and effects” of the clash, differentiating between an armed attack and a “mere frontier incident.” Footnote 97 Accordingly, commentators have concluded that “not just any violation of article 2(4) necessarily gives entitlement to a right of self-defence. A minor use of force, such as a border incident, entails its author’s international responsibility. It does not, however, allow its victim to riposte by military action,” absent a UNSC resolution. Footnote 98 Exactly when the threshold from a lesser use of force to an armed attack is crossed — and, indeed, whether it can be crossed through the accumulation of those lesser forms of military action — is uncertain. Footnote 99 It seems likely, however, that the military conduct in question must lead to “considerable loss of life and extensive destruction of property.” Footnote 100
As a result, most acts of terrorism will not rise to the level of an “armed attack” as they will be of insufficient scale or effect. The events of 11 September 2001 constitute a widely recognized exception. Footnote 101 More problematically, the UK government has asserted that “[t]he scale and effects of [Daesh’s] campaign are judged to reach the level of an armed attack against the UK.” Footnote 102 The basis for this conclusion is fragile. The UK government pointed to “six terrorist plots having been foiled in the UK in the preceding 12 months,” a problematic threshold for “armed attack” given the standards discussed above. Footnote 103 However, even if a series of terrorist incidents can be an armed attack, there is another thorny question of definition: can an “armed attack” triggering self-defence ever stem from a non-state actor?
Self-Defence and Non-State Actors
The ICJ has concluded that acts of violence directed against a state by non-state actors cannot generally trigger a right to self-defence under Article 51, at least when the non-state actor operates from within that state or from a territory occupied by that state. Footnote 104 Nevertheless, Article 51’s concept of “armed attack” does not expressly preclude violence by non-state actors against a state triggering a right to self-defence, Footnote 105 an assessment affirmed by the post-9/11 reaction. Given the enormous scale and effect of the terrorist strikes on 11 September 2001, and the fact that they were so evidently directed against the territory of the United States, the international community quickly embraced the view that self-defence against the terrorist perpetrators was warranted, despite their non-state nature. The UNSC, for instance, invoked the right to self-defence in condemning the terrorist acts. Footnote 106 For its part, the North Atlantic Treaty Organization (NATO) declared that the 9/11 acts satisfied the requirements of an “armed attack” under Article 5 of the North Atlantic Treaty, triggering a collective response from NATO. Footnote 107 The Organization of American States arrived at a similar conclusion, invoking Article 3 of the Inter-American Treaty of Reciprocal Assistance. Footnote 108
These responses, and the widespread reaction of individual states offering assistance to the United States, support the conclusion that Al-Qaeda’s terrorist act on 9/11 reached the level of an “armed attack.” Under these circumstances, a common (although not unanimous view) is that the armed response against Al-Qaeda was compliant with international law, so long as the other elements of self-defence law such as proportionality and necessity were observed. Footnote 109
Geography of Self-Defence against Non-State Actors
More awkward is the question of geography. Where a state embarks on an armed attack against another state, the locus of the response in self-defence is reasonably clear: the attacking state has territory, and the victim state’s right of self-defence serves as an obvious exception to the attacker’s rights to territorial sovereignty, again subject to the provisos of necessity and proportionality. In comparison, non-state actors are not territorial sovereigns. Directing military force against a non-state actor almost always requires, therefore, use of force on the territory of another state. In instances where a territorial state bears responsibility for the conduct of the non-state actor, the rules of attribution generally accommodate that use of force on its territory. Footnote 110 In more recent times, however, non-state actors — and, specifically, terrorist groups such as Al-Qaeda, Daesh, and Al-Shabaab — have operated from the territory of states who are either unwilling or unable to suppress their activities but are not responsible for them under classic rules of attribution.
Unquestionably, where a state consciously declines to suppress terrorist activity on its territory, it clearly violates its international obligations, Footnote 111 is arguably complicit in, and potentially has international responsibly for, attacks mounted by such groups. Where a state is incapable of suppressing these activities, that lack of capacity does injury to another state, plausibly again raising questions of responsibility. And, yet, uncooperative or under-resourced state (mis)conduct does not itself meet the definition of “armed attack” justifying military force used in self-defence. That is, the breach of a state’s international anti-terrorism obligations does not graduate to conduct that, under the UN Charter framework, justifies self-defence.
Still, there is serious incongruity in the idea that a non-state actor may use violence whose scope and effect rises to the level of armed attack and then hide behind the territorial sovereignty of a state that, however unwillingly or unwittingly, serves as the host. And as a practical matter, some states, including, especially, the United States, have rejected this formalistic approach in the area of jus ad bellum. These states have instead pursued a doctrine of “unwilling or unable.” In Ashley Deeks’ words,
[t]he “unwilling or unable” test requires a victim state to ascertain whether the territorial state is willing and able to address the threat posed by the nonstate group before using force in the territorial state’s territory without consent. If the territorial state is willing and able, the victim state may not use force in the territorial state, and the territorial state is expected to take the appropriate steps against the nonstate group. If the territorial state is unwilling or unable to take those steps, however, it is lawful for the victim state to use that level of force that is necessary (and proportional) to suppress the threat that the nonstate group poses. Footnote 112
Whether “unwilling or unable” is truly part of customary international law is hotly debated. In her exhaustive survey, Deeks identifies thirty-nine instances between 1817 and 2011 where armed attacks attributable “entirely or primarily to a nonstate armed group or a third state” prompted a military response from a victim state on a territorial state that had not consented to this use of force on its territory. Footnote 113 The most famous of these was the notorious 1837 Caroline affair between the United Kingdom and the United States. In that dispute, a British force entered the United States from Canada to scuttle a ship being used to ferry fighters and supplies to a Canadian island occupied by insurgents in preparation for an invasion of Canada. In the resulting diplomatic exchange — widely regarded as incisive in the history of international self-defence law — the United Kingdom claimed that the US federal and New York state government knowingly permitted the rebels to make their preparations or that they were incapable of controlling the border region. In either instance, the British were entitled to enter US territory since it was no longer neutral territory. Footnote 114
A handful of states have invoked similar logic in much more recent conflicts. During the post-Second World War period, Israel adopted the unwilling or unable standard to justify actions against the Palestine Liberation Organization in Lebanon and against Hezbollah in Lebanon and Syria. The United States invoked the doctrine against Al-Qaeda in Sudan, Afghanistan, and Pakistan, while Russia used it against Chechen rebels in Georgia, and Turkey used it against the Kurdistan Workers’ Party in Iraq. Footnote 115 In general, the international community has demonstrated more receptivity — although certainly not enthusiasm — for the doctrine since 9/11 and especially since 2014. Footnote 116 Most notably, events in Iraq and Syria and the conflict with Daesh have drawn more states into the category of those prepared to apply the “unwilling or unable” approach, justifying use of force against Daesh in Syria even without the consent of Syria’s Assad regime. The United States Footnote 117 and Turkey Footnote 118 have reaffirmed the existence of an unwilling or unable doctrine to justify self-defence against Daesh in Syria, and they are not alone. They have been joined by Australia, Footnote 119 Belgium, Footnote 120 Canada, Footnote 121 Germany, Footnote 122 and, implicitly at least, Denmark, Footnote 123 Norway, Footnote 124 and the United Kingdom. Footnote 125 In response to the US notification to the United Nations, then Secretary General Ban Ki-moon reportedly stated: “I also note that the strikes took place in areas no longer under the effective control of that [the Syrian] government. Footnote 126 Other states, such as Jordan, Bahrain, Qatar, and the United Arab Emirates have participated in air strikes in Syria without articulating legal justifications, leading at least one commentator to posit that they are “relying on the same legal theory as the United States and UK.” Footnote 127 Still other states, such as France, Footnote 128 have effectively embarked on a similar course under the shelter of a UNSC resolution that is creatively ambiguous about the legal authority for directing force at Daesh in Syria. Footnote 129 Collectively, this constitutes considerable state practice and, in the case of the United States, Turkey, Canada, Australia, Belgium, and Germany, emphatic opinio juris supportive of the “unable or unwilling” doctrine as a basis for invoking Article 51.
State practice of what is less clear. It is one thing to intrude on a state’s territory in order to exercise self-defence strictly limited to the attacking non-state actor. It is quite another to stray beyond this terrorist-specific targeting and direct force against the territorial state’s own assets or infrastructure. The risk of such over-breadth might be best policed through strict adherence to the separate necessity and proportionality concepts in self-defence law, which is discussed in the next section. Footnote 130
Terrorism, Necessity, and Proportionality
Even if the armed attack requirement for the use of force in self-defence is met, any armed response must be necessary and proportional. “Necessity” means that the force used in self-defence must be necessary to respond to (and presumably repel) the armed attack. In Military and Paramilitary Activities, there was no necessity where the use of force in alleged self-defence took place months after the putative armed attack had been repulsed. Footnote 131 In Case Concerning Oil Platforms (Islamic Republic of Iran v United States of America), the ICJ viewed force as unnecessary where, on the facts, it was directed at targets considered targets of opportunity by the allegedly defending state. Footnote 132 Military responses to terrorism, in particular, have often precipitated debate among states and scholars as to whether they are truly “necessary” to repel the attack or rather simply retaliatory. Footnote 133
Proportionality is usually taken to mean use of force in self-defence no greater than is required to halt and repel the armed attack — that is, proportional to the necessary military objective of countering the threat. Footnote 134 For some jurists, however, proportionality is assessed with reference to the scale of the armed attack defended against. Footnote 135 These are quite different measures. Assessed against the second standard, for instance, the response to a terrorist’s “armed attack” may become disproportionate if the consequences of the response (in civilian casualties, for instance) outstrip those of the terrorist attack. Assessed against the first standard, armed force is proportional if properly directed at dislodging the terrorists and thus forestalling the occurrence or recurrence of the attack. This is presumably true even if the exercise of force produced civilian causalities in excess of those injured in the initial attack.
Terrorism and Pre-emptive Self-Defence
A final, pressing issue in contemporary discussions of self-defence is whether the attack prompting the act of self-defence must be immediate or whether a more remote threat may justify an armed response. The issue of imminence was addressed most famously in the Caroline incident (albeit in factual circumstances where Canadian territory had already been occupied by the non-state insurgents). In their exchange of letters, the US and UK governments expressed the view, apparently shared by both sides, that self-defence was only warranted where the “necessity of that self-defence is instant, overwhelming, and leaving no choice of means, and no moment for deliberation.” Footnote 136
Article 51 of the UN Charter captures this sense of imminence. It specifies that the right to self-defence arises if “an armed attack occurs.” Whether self-defence is permitted in customary international law where the threat is less immediate is a point of contention among international lawyers. It seems plausible (although far from universally accepted) that “anticipatory self-defence” is permitted under customary international law: “[W]here there is convincing evidence not merely of threats and potential danger but of an attack being actually mounted, then an armed attack may be said to have begun to occur, though it has not passed the frontier.” Footnote 137 In the words of the International Law Association (ILA), “there may be reason to accept that when faced with the clear and present danger of a specific imminent attack, states may engage in measures to defend themselves in order to prevent the attack.” Footnote 138
Much more contentious and doubtful is whether “anticipatory self-defence” should be expanded to incorporate a concept of “pre-emptive self-defence,” sometimes referred to as the “Bush Doctrine.” In the 2002 National Security Strategy of the United States, the Bush administration asserted the right to act in self-defence against nascent threats and not just those that were imminent in the conventional or even anticipatory sense. Footnote 139 While the Bush doctrine is held in considerable disfavour among states and scholars, imminence is a particularly acute issue for militarized counter-terrorism. Footnote 140 At issue is a contest against diffuse and secretive terrorist groups inclined to sudden acts of violence in a civil population. Here, accurate predictions as to imminence may be impossible. As a US Department of Justice legal memorandum on targeted killing argues, “a ‘terrorist war’ does not consist of a massive attack across an international border, nor does it consist of one isolated incident that occurs and is then past. It is a drawn out, patient, sporadic pattern of attacks. It is very difficult to know when or where the next incident will occur.” Footnote 141 For similar reasons, the UK government now endorses a “flexible approach” to imminence that would “include an ongoing threat of a terrorist attack from an identified individual who has both the intent and the capability to carry out such an attack without notice.” Footnote 142
Summary
The legal doctrine discussed in this part necessarily guides Canada’s military response to foreign fighters. The applicable rules can be summarized in the following way. Absent consent from the territorial state or UNSC authorization, Canada may not use force on the territory of another state except in response to an armed attack. This general proposition is without doubt. But the specific application raises interpretative controversy concerning the concept of use of force and the self-defence exception. There are restrictive and more permissive construals of both of these concepts, applicable in armed responses to foreign fighters. A restrictive view of international law doctrine on the use of force would be that in the absence of an UNSC resolution or where the territorial state has not given consent and is not itself responsible for the armed attack, Canada cannot deliberately send military forces onto another state’s territory to take any sort of forcible action, even strictly against non-state actors. A more permissive construal of the use of force concept would be that Canada may conduct a surgical, limited military strike within the territory of another state directed strictly against a non-state actor that does not involve an actual clash with the territorial state’s forces. This view hinges on a de minimis concept of use of force that would take pinprick-style military action outside the scope of Article 2(4) of the UN Charter and vitiate any need to justify the action as a matter of self-defence in response to an armed attack. As such, it is not an approach that appears to have garnered much state practice or scholarly support.
However, even applying a more conventional analysis, and considering the matter with an eye to the law of self-defence, there are restrictive and permissive construals of at least the concept of armed attack, imminence, the identity of the attacker, the geography of the response, proportionality, and necessity. Table 1 lays out the choices on all of these issues that Canadian policy makers would need to make.
Table 1: Disputes in the Law of Self-Defence
As our discussion in this section suggests, it is unlikely that either the purely restrictive or the purely permissive approaches to self-defence constitute international law. In our estimation, the following statement expresses a plausible estimate of the present state of the law. An armed attack involves a considerable loss of life or destruction of property that must be at least en route, if not already suffered. The attacker whose conduct triggers the right to self-defence may be a non-state actor. Self-defence may be conducted on the territory of a state that is unwilling or unable to respond to the armed attack undertaken by a non-state actor from its territory. But the defending state cannot target the territorial state’s own assets unless the conduct of the non-state actor is properly attributable to the territorial state under the separate rules of attribution in international law. The proportionality of the self-defence conduct is judged by what is required to stave off the armed attack and may result in a use of force, the consequences of which exceed the consequences of the armed attack itself. But a use of force is necessary only where it is needed to stop a plausibly persisting and ongoing armed attack and is not simply retaliatory.
Targeted Killing in an Armed Conflict against Terrorists
Regardless of the legitimacy of a use of force, as measured by jus ad bellum, the actual manner in which violence is used in that military response must comply with the jus in bello. The core content of this jus in bello includes IHL. For the purposes of this article, IHL’s most important rule is that of “distinction”: “The parties to the conflict must at all times distinguish between civilians and combatants. Attacks may only be directed against combatants. Attacks must not be directed against civilians.” Footnote 143 As this principle suggests, IHL partitions people into combatants and civilians. Generally speaking, combatants may target and kill other combatants without that conduct constituting a war crime — in international armed conflicts, this is part of what is meant by “combatant’s immunity.” Generally speaking, civilians may not be targeted, although they do not enjoy absolute protection against being killed. The targeting of civilians is a war crime. However, IHL accepts that civilians may be “collateral casualties,” to use the colloquial phrase. That is, they may be injured or killed, though not targeted, where that outcome is proportional to a concrete and direct military advantage in the conflict between combatants. Footnote 144
As a result of the important legal dichotomy between combatants and civilians, IHL includes criteria for these statuses. In classic, inter-state conflicts (known in IHL parlance as “international armed conflicts”), state armed forces are typically arrayed against other state armed forces, distinguished from civilians by such things as uniforms and command structures. In “non-international armed conflicts” (NIACs), which have been, classically, civil conflicts and, more recently, ill-defined contests between states and shadowy networks of terrorists and insurgencies, these fine points of demarcation blur. Rebels, insurgents, and terrorists generally do not wear distinguishing emblems, for instance. Instead, they are generally embedded in a civilian population, distinguishable only by their violent conduct and not by any other means.
terrorists and direct participation in hostilities
As a result of the practical difficulties of distinction in many conflicts, IHL acknowledges a hybridized status: civilians who participate actively in the armed conflict. Thus, “[c]ivilians are protected against attack, unless and for such time as they take a direct part in hostilities.” Footnote 145 Exactly what it means to take a direct part in hostilities is contested. In the International Committee of the Red Cross (ICRC)’s words, “[a] precise definition of the term ‘direct participation in hostilities’ does not exist.” Footnote 146 It is relatively uncontroversial to assert that those who organize themselves as an armed group to take continuous and direct part in hostilities lose their protected status as civilians. Footnote 147 But more episodic participation in hostilities raises greater complexities. For instance, can a state’s military forces target the person who is a baker by day and an insurgent by night during the period in which that person is baking?
In a 2009 guidance document, the ICRC proposes a series of tests responsive to this situation. The first set of proposed requirements requires a causal link between the person’s intentional violent conduct and sufficiently injurious military consequences or “death, injury, or destruction” of “persons or objects protected against direct attack.” Footnote 148 Direct participation also includes “measures preparatory to the execution of a specific act of direct participation in hostilities, as well as the deployment to and the return from the location of its execution.” Footnote 149 Controversially, however, the guidance limits the civilian’s loss of protected status to “the duration of each specific act amounting to direct participation in hostilities.” Footnote 150 Put another way, the baker cannot be targeted during his day job.
The result is a “revolving door” between protected and combatant status, an outcome contested by some states. The United States, for instance, sees direct participation as a threshold that, once crossed, renders the person liable to targeting until that person has permanently ceased participation in hostilities. Footnote 151 Canada’s official position has not been so clearly enunciated, at least publicly. Footnote 152 It is not certain, therefore, what stance Canada’s judge advocate general would take on the targeting of a civilian who has taken direct part in hostilities but who is not so engaged at the time of targeting. Nevertheless, the bottom line is clear: once IHL becomes the applicable legal standard, deadly force can usually be used against combatants and those civilians who have abandoned their protected status by participating directly in hostilities. The key threshold issue, therefore, is whether IHL applies at all, permitting recourse to this lethal force.
trigger for ihl
IHL applies in circumstances of armed conflict, a term that is not precisely defined. The existence of an armed conflict does not require a declared war. Footnote 153 Instead, armed conflict usually requires the use of military force reaching a certain threshold of intensity. It does not, for instance, exist simply by reason of “riots, isolated and sporadic acts of violence,” Footnote 154 “banditry, unorganised and short lived insurrections or terrorist activities,” Footnote 155 and “civil unrest, [and] single acts of terrorism.” Footnote 156 In practice, the applicable threshold varies depending on the nature of the armed conflict. The ICRC urges that the threshold is very low for conflicts between states (international armed conflicts): “Any difference arising between two States and leading to the intervention of armed forces is an armed conflict, … even if one of the Parties denies the existence of a state of war. It makes no difference how long the conflict lasts, or how much slaughter takes place.” Footnote 157
The threshold for NIACs — that is, conflicts between states and non-state actors — is more demanding. In deciding the application of IHL, the international criminal tribunals for the former Yugoslavia and Rwanda have suggested that acts of violence between states and non-state actors must be “protracted” for a situation of “armed conflict” to arise. Footnote 158 How this test relates to counter-terrorism is murky. For instance, it has not always been clear that the NIAC concept extends to actions against terrorists who are acting clandestinely as part of a diffuse, geographically disparate network and who are not acting as dissident armed forces controlling territory. Footnote 159 Part of this difficulty stems from uncertainty as to the level of organization that must be exhibited by a non-state actor before his or her acts of violence can be said to give rise to an armed conflict. On the one hand, “[v]iolence perpetrated by the assassin or terrorist acting essentially alone or the disorganized mob violence of a riot is not armed conflict.” Footnote 160 On the other hand, a non-state actor coheres sufficiently for the purposes of satisfying the criteria for the existence of an armed conflict where, e.g., there is a “command structure; exercise of leadership control; governing by rules; providing military training; organized acquisition and provision of weapons and supplies; recruitment of new members; existence of communications infrastructure; and space to rest.” Footnote 161 Nominal adherence to a shared ideology would not, on these standards, make an organization out of individual terrorists.
Second, the intensity threshold is itself ambiguous. Non-determinative factors used to gauge whether violence has reached the requisite intensity level include “the number of fighters involved; the type and quantity of weapons used; the duration and territorial extent of fighting; the number of casualties; the extent of destruction of property; the displacement of the population; and the involvement of the Security Council or other actors to broker cease-fire efforts.” Footnote 162 As noted above, this violence must also occur over a “protracted period.” Footnote 163 These considerations of organization, intensity, and protraction interact: “[I]ntensity and protraction, are linked and a lesser level of duration may satisfy the criterion if the intensity level is high. The reverse is also the case. The idea of ‘protraction’ is also relevant to the ‘organisation’ criterion, as it requires a certain level of organisation to undertake protracted hostilities.” Footnote 164
Applying these standards to an extraterritorial terrorist movement creates real dilemmas. The prevalent view in the United States is that the intensity test cumulates geographically disparate acts by such terrorist groups, allowing an armed conflict to arise even where there is no “hot” theatre of hostilities. Footnote 165 The obvious difficulty with this approach is that it depends on these disparate acts being attributable to a tangible organization with whom the state then enters into armed conflict. It demands that “the groups concerned can reasonably be characterized as a single coherent organization operating collaboratively.” Footnote 166 Measuring the organizational coherence of a secretive terrorist enterprise is difficult, especially when the organization morphs into ideology, and so-called “lone wolf” terrorists can unilaterally affiliate with a simple tweet. Practically speaking, a threshold dependant on some measure of coherent organization is unhelpfully uncertain in defining the scope of a non-international armed conflict. Footnote 167
The alternative limiter is geography. On this issue, again, there is debate about whether a NIAC is confined to a zone of “hot” hostilities. The generally accepted position within the United States has been that IHL governs its use of military force against Al-Qaeda (and, increasingly, Daesh) globally, Footnote 168 at least where Al-Qaeda or an associated force “has a significant and organized presence and from which Al-Qaida or an associated force, including its senior operational leaders, plan attacks against U.S. persons and interests.” Footnote 169 This position has not been widely embraced outside the United States. The ICRC, for instance, urges:
[T]he notion that a person “carries” a NIAC with him to the territory of a non-belligerent state should not be accepted. It would have the effect of potentially expanding the application of rules on the conduct of hostilities to multiple states according to a person’s movements around the world as long as he is directly participating in hostilities in relation to a specific NIAC. Footnote 170
The ILA has also voiced resistance to geographically diffuse NIACs:
If armed conflict exists when organized armed groups are engaged in intense fighting, then, logically, armed conflict does not begin until these criteria are present; armed conflict ends when the criteria are no longer present, and armed conflict extends to territory where organized armed fighting is occurring … States rarely recognize armed conflict beyond the zone of intense fighting, whether the fighting is in an international or non-international armed conflict.” Footnote 171
Likewise, having reviewed the threshold criteria for NIACs, the UN special rapporteur on extrajudicial executions concluded in 2010:
[T]hese factors make it problematic for the US to show that — outside the context of the armed conflicts in Afghanistan or Iraq — it is in a transnational non-international armed conflict against “al Qaeda, the Taliban, and other associated forces” without further explanation of how those entities constitute a “party” under the IHL of non-international armed conflict, and whether and how any violence by any such group rises to the level necessary for an armed conflict to exist. Footnote 172
The best that can be said about these questions is that they are contested. And exactly where the Canadian government stands on these issues is not clear, at least to us.
Before leaving these matters, it is worth underscoring their implications in a concrete context. By any standard, the conflict with Daesh — currently in possession of territory — qualifies as a NIAC in Syria and Iraq. Less clear is the application of IHL to those persons who claim affiliation with Daesh in places outside of the zone of active hostilities. Under the geographically unbounded, cumulative theory of intensity, IHL would apply to these distant locations — for instance, Libya, Bangladesh, or, indeed, any other state where sufficiently organized individuals assert a Daesh allegiance, regardless of the existence (or not) of hostilities on these territories. Indeed, the armed conflict would persist for some analysts even if Daesh were displaced from its present territory and became solely a geographically indefinite, extraterritorial terrorist movement, so long as the acts of violence attributable to it and cumulated worldwide met the “protracted” intensity threshold. But, as the Daesh phenomenon becomes an ideological movement and less an organizational enterprise, how does one incorporate lone wolf acts of violence into that intensity accounting? For example, would the terrorist murder in Orlando in June 2016 by an individual simply inspired by Daesh (and, indeed, reportedly also drawing inspiration from groups like Al-Qaeda, which is at odds with Daesh) contribute to a conclusion that a state of NIAC persists?
The risk of applying the NIAC analysis in a manner that allows for the aggregation of terrorist violence done in the name of a particular cause is obvious. Human rights law (discussed further below) is at least partially displaced as IHL is triggered, and the IHL legal regime permits the intentional targeting of combatants with lethal force and is accepting of proportional injury and death to civilians. In summary, as with jus ad bellum, there are restrictive and permissive construals of the applicable rules of IHL. Table 2 sets out the current dilemmas. We do not believe that there is currently sufficient state practice to resolve these matters definitively, although we are inclined to view the notion of a geographically diffuse NIAC advanced by the United States with considerable suspicion.
Table 2: Disputes in the Law of Armed Conflict
Lethal Force and Peacetime Counter-terrorism
Outside of an armed conflict, the applicable rules governing targeted killings come from international human rights law. Footnote 173 Human rights law is much less accommodating of lethal force than international humanitarian law. Article 6 of the International Covenant on Civil and Political Rights (ICCPR), for instance, specifies: “Every human being has the inherent right to life. This right shall be protected by law. No one shall be arbitrarily deprived of his life.” Footnote 174
Application of this (and other) human rights norms to targeted killings of terrorists operating from foreign states raises complexities of its own, different in form (although not in kind) from those associated with IHL. First, there is no absolute prohibition on the use of lethal force under international human rights law; it may be permissible in circumstances of exigency. Second, there is considerable uncertainty concerning the geographic reach of the ICCPR and, by consequence, its relevance to extraterritorial targeted killings. Third, the ability to use legal force in peacetime may be confounded by still other, geographic-based strictures in international law.
lethal force
Human rights law is not a suicide pact. The UN Code of Conduct for Law Enforcement Officials provides: “Law enforcement officials may use force only when strictly necessary and to the extent required for the performance of their duty.” Footnote 175 Likewise, the UN Basic Principles on the Use of Force and Firearms by Law Enforcement Officials specifies that officials may resort to such measures where “other means remain ineffective or without any promise of achieving the intended result.” Footnote 176 Where violence is unavoidable, officials must “exercise restraint in such use and act in proportion to the seriousness of the offence and the legitimate objective to be achieved,” among other things. Footnote 177 The UN special rapporteur on extrajudicial, summary, or arbitrary executions described these particular principles as “rigorous applications of legal rules that States have otherwise assumed under customary or conventional international law.” Footnote 178 He concluded that recourse to lethal force is lawful (and may even be obligatory) by state officials in exigent circumstances, where the lives of others are at stake, but is constrained by strict standards of necessity and proportionality. Footnote 179 Summarizing the applicable standards, Special Rapporteur Philip Alston noted:
A State killing is legal only if it is required to protect life (making lethal force proportionate) and there is no other means, such as capture or nonlethal incapacitation, of preventing that threat to life (making lethal force necessary). The proportionality requirement limits the permissible level of force based on the threat posed by the suspect to others. The necessity requirement imposes an obligation to minimize the level of force used, regardless of the amount that would be proportionate, through, for example, the use of warnings, restraint and capture. Footnote 180
Critically, this “law enforcement” standard is dramatically different from those applicable in IHL. Footnote 181 IHL permits the killing of combatants and imposes proportionality strictures to ensure minimal impact on non-combatants. Conversely, human rights law prohibits killings and is only relaxed pursuant to proportionality and necessity standards driven by the need to save others. Thus, as Special Rapporteur Alston notes, “under human rights law, a targeted killing in the sense of an intentional, premeditated and deliberate killing by law enforcement officials cannot be legal because, unlike in armed conflict, it is never permissible for killing to be the sole objective of an operation.” Footnote 182
This position is relatively non-contentious. More problematic is the application of this standard to extraterritorial state conduct. The question of “necessity” will be measured quite differently when the perceived imminent threat is located in a far-off land as opposed to a state’s own territory. Within the state’s territory, dangerous people are more readily amenable to capture and detention. When the person posing the threat is overseas, these non-lethal forms of incapacitation may be impractical, if not impossible, especially where the territorial state is uncooperative. Footnote 183 What is more, the loss of life by forces tasked with a capture mission may pose an unacceptable risk for state leaders. Footnote 184 Finally, to the extent that necessity also implicitly requires imminence Footnote 185 — the sense that the feared violence is so proximate other strategies are implausible — distance also matters. Imminence may be a more pliable concept when the person is at a distance and perhaps only ephemerally within the targeting state’s reach. The US targeted killing legal position asserts, for instance, “imminence must incorporate considerations of the relevant window of opportunity, the possibility of reducing collateral damage to civilians, and the likelihood of heading off future disastrous attacks on Americans.” Footnote 186 Taken together, all of these considerations may convert a “necessity” standard into one of “expediency.”
geographic conundrums
The law enforcement justification for lethal force poses two, more general, problems.
The Reach of State Human Rights Obligations
First, there is considerable uncertainty concerning the extraterritorial reach of the ICCPR and, as a consequence, the right to life under it. Article 2 describes the scope of a state’s overall ICCPR obligations as follows: “Each State Party to the present Covenant undertakes to respect and to ensure to all individuals within its territory and subject to its jurisdiction the rights recognized in the present Covenant.” An important issue, therefore, is whether individuals subject to extraterritorial intelligence collection are within the “territory and subject to [the state’s] jurisdiction.” Article 2 talks about territory and jurisdiction, implying either that both must be coincident for the obligation to attach to a state or that the two concepts are alternative descriptions of the ICCPR’s reach. The first position seems a more plausible construction of the grammar. The second possibility is accommodated by international law, which clearly views jurisdiction and territory as separate concepts. For instance, states may exercise prescriptive jurisdiction in relation to their nationals, irrespective of their location. Footnote 187
Importantly, both the UN Human Rights Committee (HRC) and the ICJ have opted for the broader construction. They have concluded that individuals may be within a state’s jurisdiction, even while not on its territory. In the original HRC case in which this doctrine was first pronounced, a Uruguayan citizen was kidnapped, abused, and secreted out of the country by Uruguayan security agents operating in Argentina. Footnote 188 The HRC considered that the victim was nevertheless within the jurisdiction of Uruguay. More recently, the HRC and the ICJ have concluded that a person may be within a state’s jurisdiction when that person is within the power or “effective control” of the state, even if he or she is not in the state’s territory. Footnote 189 This position is contested by several states, including the United States. Footnote 190 Canada’s own position on the extraterritorial reach of the ICCPR appears ambiguous but sceptical. Footnote 191 But even if the “effective control” test is good law, it is not entirely clear that it offers any safeguard against targeted killing. “Effective control” is really about the status of the victim — specifically, are they under the control of the state? While it stands to reason that someone physically detained by a state is within its effective control, a person targeted by a drone missile (and in no way in the targeting state’s physical control) may not be. In consequence, this “status-of-the-victim” approach to the ICCPR’s geographic reach risks a serious incongruity: human rights may demand more of detaining states than they do of states that kill from a distance.
Unfortunately, the effective control test gives every appearance of being concocted initially by the UN HRC and lately by the ICJ without an eye to traditional rules of state responsibility. These later standards depend more on the identity and degree of (and effective control over) the perpetrator of an unlawful act, not on the state’s control over the victim. Footnote 192 And, thus, the precise reach of the ICCPR to extraterritorial targeted killing is unhelpfully ambiguous. There are two rebuttals to this concern, each having the effect of imposing human rights obligations on extraterritorial targeted killing. First, authorities have described the right to life “as a general principle of international law and a customary norm. This means that, irrespective of the applicability of treaty provisions recognizing the right to life, States are bound to ensure the realization of the right to life when they use force, whether inside or outside their borders.” Footnote 193 Second, “[i]t has been argued that the deliberate killing of selected individuals through extraterritorial drone strikes is likely to bring the affected persons within the jurisdiction of the operating State” because “human rights treaties cannot be interpreted so as to allow a State party to perpetrate violations of the treaty on the territory of another State, which it could not perpetrate on its own territory.” Footnote 194
Sovereignty Issues
Even if human rights law does not have cross-border reach, other rules of international law would apply to peacetime targeted killings. Most notable among these are classic rules of sovereignty. In circumstances where the laws of armed conflict apply, conventional doctrines precluding interference in the sovereign affairs of other states are inapplicable. However, in the absence of either a UNSC resolution authorizing use of force or an armed attack justifying self-defence, these regular sovereignty norms apply in full. Sovereignty contains several ingredients, one of which is the principle of non-intervention, which is part of customary international law. Footnote 195 In Military and Paramilitary Activities, the ICJ concluded that, at a minimum, the principle of non-intervention
forbids all States or groups of States to intervene directly or indirectly in internal or external affairs of other States. A prohibited intervention must accordingly be one bearing on matters in which each State is permitted, by the principle of State sovereignty, to decide freely. One of these is the choice of a political, economic, social and cultural system, and the formulation of foreign policy. Footnote 196
As previously highlighted, in the particular context of Military and Paramilitary Activities, the ICJ concluded that prohibited interventions included “methods of coercion,” even when these fell short of the use of force. Footnote 197 On a similar basis, some commentators have concluded that to constitute unlawful “intervention the interference must be forcible or dictatorial, or otherwise coercive, in effect depriving the state intervened against of control over the matter in question. Interference pure and simple is not intervention.” Footnote 198 It is arguable whether a targeted killing directed at a non-state actor on another state’s territory constitutes coercion against that state and, thus, interference in its affairs.
But, more critically, there are other, more general strictures on the exercise of state power across borders. Famously, the Permanent Court of International Justice in the SS Lotus case noted:
[T]he first and foremost restriction imposed by international law upon a State is that — failing the existence of a permissive rule to the contrary — it may not exercise its power in any form in the territory of another State. In this sense jurisdiction is certainly territorial; it cannot be exercised by a State outside its territory except by virtue of a permissive rule derived from international custom or from a convention. Footnote 199
The exercise of state power is known as “enforcement jurisdiction,” and the prohibition on the imposition of non-consensual enforcement jurisdiction extraterritorially, on the territory of another state, remains a bedrock principle of international law: “[T]he legal regime applicable to extraterritorial enforcement is quite straightforward. Without the consent of the host State such conduct is absolutely unlawful because it violates that State’s right to respect for its territorial integrity.” Footnote 200 In the result, international law precludes non-consensual, extraterritorial conduct jure imperii — that is, involving the exercise of government functions. Footnote 201 This would certainly extend to a state’s use of physical force on the territory of another state Footnote 202 and unquestionably include a targeted killing. Indeed, it also includes captures and arrests. Footnote 203
All of this is to say that regardless of whether human rights law governs a state’s overseas activities, and regardless of whether a law enforcement justification for use of lethal force is reconcilable with that human rights law, nothing in international law permits the exercise of this (or any other kind of) power on the territory of another state, without its consent, absent the same sorts of justifications that trigger a right to self-defence. This is true even if one accepts that there is a de minimis form of force that is not regulated by Article 2(4) and that this de minimis threshold is not exceeded by targeted killings. Even if a targeted killing abroad is not a use of force per se, it is still an exercise of enforcement jurisdiction and therefore prohibited by international law. The only exception to the enforcement jurisdiction and sovereignty rules would be circumstances where the standards of Article 2(4) and its exceptions were met, such as self-defence in relation to an “armed attack.” However, in most instances, it seems likely that once the threshold of “armed attack” validating self-defence has been crossed, the matter has reached the point of an “armed conflict” within the meaning of IHL, negating the need to rely on the law enforcement justifications for lethal force at all. The attacks of 9/11, for instance, were both an armed attack under jus ad bellum standards and also likely constituted enough to initiate an “armed conflict” triggering IHL rules.
We believe that only in the narrowest circumstances would the degree of violence meeting the “armed attack” threshold be insufficient to meet the intensity test for a NIAC. But one key possibility presents itself. To the extent that self-defence rules permit anticipatory action, it may be the case that hostilities have not actually arisen before military force is taken in self-defence. Thereafter, a single targeted killing in self-defence may not, alone, constitute the protracted hostilities required to meet the jus in bello threshold for “armed conflict.” In the result, we may have an exercise of military force in self-defence, but not clearly governed by IHL. As a policy matter, militaries may wish nevertheless to respect IHL standards in such circumstances. Footnote 204 This would be problematic, as it opens the door to IHL’s more accepting views on killing. Instead, we propose the following implications of an anticipatory “first strike” in self-defence: the rules of enforcement jurisdiction are suspended through the operation of jus ad bellum self-defence standards, but the human rights rules for the use of lethal force persist.
Guidance on Canadian Targeted Killings
In this final section, we propose an analytical framework for approaching a Canadian targeted killing. In so doing, we do not opine on the wisdom or necessity of such a course of action. Rather, our objective is to lay out concretely the legal issues a Canadian government would need to resolve should it decide that national security demands the extraterritorial targeted killing of a Canadian citizen. Our purpose is to underscore precisely how many choices the government would need to make regarding matters of law that are contested.
domestic legal questions
Would the government commit a crime in ordering a targeted killing? Would the government breach the Charter in ordering a targeted killing?
Canadian soldiers would not be culpable of a crime unless their acts violated Canada’s war crimes laws or the Criminal Code. A use of military or lethal force compliant with international law could plausibly satisfy these standards, either because it falls outside the scope of a war crime or because it is justifiable under a Criminal Code defence. In relation to the Charter, again, we believe the key inquiry here would be adherence to international law standards. Footnote 205
international legal questions
Assessing the international legality of Canada’s conduct would require, at minimum, consideration of the following matters. We assume for the purposes of this discussion that a use of force has not been authorized by a UNSC resolution.
When can Canada use military force on the territory of another state?
Where the target (or his or her organization) is already engaged in conduct that risks considerable loss of life or destruction of property in Canada, he or she is conducting an “armed attack.” This attack should be sufficiently imminent. Exactly what this means in the realm of militarized counter-terrorism is contested, requiring Canada to make a choice. We prefer an approach that requires the attack to be en route — that is, some physical steps have been taken to bring it about — rather than merely a perceived conspiracy. Similarly, a target’s membership in an organization that has called for attacks against Canada or generally threatened to engage in acts of violence against Canada is, on its own, insufficient to make them an imminent threat. Footnote 206
In response to an imminent armed attack, Canada may, in the absence of other alternatives, engage in a proportional use of military force that is required to stave off this attack. This force may be directed against the target on the territory of a state where that state consents and (more controversially) if that state is unwilling or unable to respond to the armed attack undertaken by the non-state actor. Since the air war in Syria, Canada has already endorsed the unwilling and unable doctrine. Whether the Trudeau government’s choice to cease such operations may signal its uneasiness with the doctrine as a justification for military action is unclear at this time. In the absence of such an “armed attack,” Canada is not legally entitled to use military force or otherwise engage in any form of enforcement jurisdiction on the territory of a non-consenting state. Even where a state consents, the legality of that use of force is governed either by IHL, if there is an armed conflict, or untempered international human rights law obligations where there is no armed conflict.
What sort of force could Canada use?
Two possible bodies of law govern the kind of military force that may be used.
Is there an armed conflict?
If the armed attack (and the response to it) are part of (or amount to) protracted hostilities between Canada and an organized armed group, the targeted killing is part of an armed conflict and is governed by IHL. This would be true so long as the targeting takes place in the state in which an armed conflict exists because of sufficiently protracted hostilities there with an organized non-state actor and such other places in which the hostilities with an organized non-state actor are also sufficiently protracted, such as adjacent “spillover” regions. We prefer, in other words, a narrow geographic delimiter on the application of IHL, thereby preserving a broad reach for international human rights law. On this question too, however, Canada would need to make a choice between the narrower geographic standard we support and the more permissive view on the geographic extent of an armed conflict taken by the United States. If the armed attack is merely anticipated, and there have been no actual hostilities, it seems likely the targeted killing is not conducted as part of an armed conflict. Instead, international human rights law applies, in full, without the need to reconcile it with IHL.
What standards apply if there is an armed conflict?
IHL and human rights law impose different standards that would govern the targeted killing. IHL permits the targeted killing of civilians engaged in direct participation in hostilities, including measures preparatory to the execution of a specific act of direct participation in hostilities. What this means in practice is not settled. We prefer the narrower approach to the “revolving door” question — limiting the targeting to the period of actual participation in hostilities — with other circumstances governed by human rights law, discussed below. Here too, Canada would be making a policy choice on the shape of the governing law. That said, how much the revolving door issue matters in relation to foreign terrorist fighters is debatable. It may not be necessary to draw the line between fighting and more mundane activities when the target is a Canadian who chooses to travel to a foreign country for the singular purpose of joining and supporting the violent activities of a terrorist organization. This is a person who appears to have opted to take a continuous and direct part in hostilities and who has therefore lost their protected status as a civilian.
What standards apply if there is no armed conflict?
Where international human rights law applies in full, targeted killing is only legal if necessary to protect life and there are no other means, such as capture or non-lethal incapacitation, of protecting that life. Put another way, Canada could only use the least amount of force against the target necessary to protect life. The sole purpose of the targeting cannot be to kill. In applying this standard, Canada would be agreeing that its human rights obligations extend extraterritorially, either as a matter of customary international law of the sort discussed above or because of a broad construal of Article 2 of the ICCPR (both in terms of geographic scope and what it means to be in a state’s “effective control”). As noted, Canada has shown no enthusiasm for the extraterritorial reach of the ICCPR.
Where the basis for the use of force on the territory of another state is grounded in self-defence, we suspect that the human rights necessity and proportionality analyses would overlap in practice with considerations of necessity and proportionality in assessing the force that can be used in self-defence. Where the basis for the use of force on the territory of another state is consent by that territorial state, the human rights necessity and proportionality tests would need to be undertaken independently — but still undertaken.
Conclusion
Based on the assessment in this article, targeted killing may be legal in international law. As a result, it may also be legal in domestic law, to the extent that the latter is indexed to international law. But the details matter. Applying uniformly the more constraining construals of international law discussed in this article would greatly limit the prospect of such killings and, indeed, probably make them legally possible in only extremely narrow situations. Applying uniformly the permissive construals of international law would create broad reach for targeted killings.
As we have suggested, the most likely course involves a mix of permissive and restrictive construals on the many uncertain legal issues in this area. We end, however, with a specific caution. Transparency on the legal basis of targeted killings by those states that engage in it has been modest, giving rise to the fear that such killings amount simply to expedient assassinations. Should the Canadian government embark on the path of targeted killings of Canadian nationals abroad (and, indeed, the extraterritorial use of force at all outside conventional “hot” armed conflicts), it should aim to meet a higher standard of accountability. The UK parliamentary committee studying the United Kingdom’s 2015 targeted killings made repeated observations about the indefiniteness of the UK government’s legal positions on key issues, a sobering assessment. It also observed, correctly, that
for the Government’s policy to command public confidence, and to make it more likely that decisions pursuant to it do not lead to breaches of the right to life, the decision-making process must be robust, with sufficient challenge built into the process, rigorous testing of intelligence to minimise the risk of mistakes, and access to the requisite advice including legal advice at the appropriate stages in the process. Footnote 207
After all, targeted killing both presumes guilt and applies the sternest sanction any state could impose. It follows that for the sake of its credibility — and to preserve its personnel from legal exposure — the Canadian government should make its choices on the difficult legal conundrums raised in this article now rather than in the midst of a crisis. What is more, the government should articulate and debate those positions openly since these questions demand difficult policy choices that are not, in many instances, preordained by clear, existing law.
