I. INTRODUCTION
One of the more striking features of the ongoing crises in Libya, Syria and Iraq is that the resultant use-of-force debates have not been confined to foreign ministries or the United Nations Security Council (UNSC), but have spilled over into many domestic assemblies. Executive-led justifications of proposed uses of force based upon accounts of national interest and international law might have triggered these debates, but they have been shaped by the legacy of the ‘new-world-order’ humanitarian interventions of the 1990s and the post-9/11 invasions of Iraq and Afghanistan. Our article evaluates whether this turn towards domestic use-of-force arrangements is aimed at circumventing inconvenient UN mechanisms. Orthodox accounts of international law have long treated the legitimacy of domestic constitutional arrangements for authorizing force as irrelevant to the question of whether military action is legal.Footnote 1 Thus, when the United States (US) has historically characterized uses of force as ‘police actions’,Footnote 2 or when President Barack Obama invoked the 2001 Authorization for the Use of Military Force to intervene in Syria and Iraq in 2014,Footnote 3 these evasions of the US Constitution's requirement of congressional approval of military actionFootnote 4 have generally been thought not to affect these actions’ compliance with international law.Footnote 5 In this article we treat the United Kingdom (UK) as our primary case study of State efforts to use domestic authorization to sidestep the Charter's strictures. The UK's permanent UNSC membership, its shifting domestic use-of-force arrangements and its invocation of novel legal bases for action combine to make its State practice worthy of particular study.
In the course of House of Commons debates over the UK's involvement in airstrikes in Libya, Syria and Iraq since 2011, legal justifications for action have included humanitarian interventionFootnote 6 and collective/individual securityFootnote 7 in addition to UNSC resolutions. Shifting circumstances and justifications complicate the question of whether a use of force complies with international law, and they can serve to cloak proposed military actions in superficially-impressive legalese when the factual situation is difficult to ascertain. Such complication has not, however, impeded efforts to enhance Parliament's role in the use-of-force authorization process at the expense of international institutions.
Historically, UK legislators played little role in authorizing uses of force. As one judge put it bluntly in the 1960s, ‘[a] schoolboy's knowledge of history is ample to disclose some of the disasters which have been due to parliamentary … attempts at control’.Footnote 8 Notwithstanding the dawn of democratic governance, Parliament remained sidelined by executive dominance of the war prerogative throughout the twentieth century. When the UN Charter invested the UNSC with the responsibility for authorizing responses to threats to international peace and security, Parliament appeared further marginalized. In the twenty-first century, however, a constitutional convention has rapidly emerged by which the House of Commons' agreement is ordinarily necessary to authorize military action.Footnote 9
The orthodox explanation of this development is that, amidst the ongoing fallout from the 2003 Iraq War, ministers have been obliged to gain Parliament's assent to demonstrate their commitment to thorough oversight of the use of force.Footnote 10 This development has been cast in a positive light, as bringing ‘necessary democratic balance’ to use-of-force decisionsFootnote 11 and providing an additional check against abuses of power.Footnote 12 We maintain, however, that Parliament's developing role poses serious risks. MPs have become a key audience for Government efforts to vest extraordinary legal significance in UK State practice. Unlike other States, where legislative approval for use of force is ordinarily predicated upon separate UNSC authorization,Footnote 13 the parliamentary process is not explicitly envisaged as supplementing the Charter's requirements. The newfound ministerial willingness to submit use-of-force decisions to Parliament may well mark an effort to supplant, rather than supplement, international mechanisms for legitimating the use of force.Footnote 14
We open our account with an explanation of the multiple conceptions of legitimacy in the context of the use of force and how governments can manipulate this indeterminacy to generate a basis for military action. We then trace the development of two trends in UK use-of-force decision making. We designate the first trend as the external dimension, because it deals with the UK Government's interpretation of when military action is in accordance with international law. Rather than exhaustively recounting the controversial recent history of humanitarian intervention or anticipatory self-defence, we specifically address how the UK Government has sought, through its characterization of State practice, to bring about changes to international law. Parliament's expanding role in use-of-force decisions provides the internal dimension of the UK's changing practice. We examine how the UK Government has combined parliamentary authorization with novel legal bases for action to facilitate the use of military force. In his efforts to persuade Parliament to authorize interventions in Libya in 2011, Syria in 2013, Iraq in 2014 and again in Syria in 2015, Prime Minister David Cameron has repeatedly sought to relegate international institutions to the margins. While many parliamentarians have maintained the need for engagement with international mechanisms to legitimate the use of force the approach taken by the Executive potentially gives free rein to unilateralist and hegemonic exercises of military power.
II. LEGALITY AND LEGITIMACY IN THE USE OF FORCE
Given humanitarian intervention's scant grounding in international law,Footnote 15 commentators have exposed how, during NATO's 1999 Kosovo intervention, participating States began to cast the doctrine as legitimate rather than legal. The shift in language was not subtle. At the height of NATO's airstrikes, Former Prime Minister Tony Blair declared that this was ‘a just war, based not on any territorial ambitions but on values’.Footnote 16 A month later, UK Foreign Secretary Robin Cook dismissed questions over the legality of using force as a distraction from ‘the evil that we are fighting’.Footnote 17 Bruno Simma came perilously close to endorsing such claims by asserting that the Kosovo intervention could ‘with all due caution … be regarded as legitimately, if not legally, following the direction of … UN decisions’.Footnote 18 This shift was not a mere linguistic trope. Whereas the legality of a use of force is dependent upon compliance with rules of international law, the legitimacy of such an action is arguably the product of a combination of legal, political and moral considerations which do not necessarily align.Footnote 19 The balance between these factors can shift, depending upon whether a government is seeking to persuade international institutions or a domestic audience that a proposed military action is legitimate. The concept of legitimacy can therefore be grounded in ‘particular values and on unilateral or partial appreciations’ of an action,Footnote 20 providing a level of indeterminacy which can be exploited when militarily powerful countries seek to evade international law's restrictions upon military force.
Nonetheless, Anthea Roberts suggests that a binary account of the relationship between legality and legitimacy is unhelpful: ‘one of the functions of law is to help delimit legitimate actions from illegitimate actions and thus help guide behaviour’.Footnote 21 When we speak of ‘legalised’ legitimacy (derived in part from a rules-based assessment of the validity of actions), political legitimacy (derived from the democratic accountability of the actors involved in a decision), and moral legitimacy (derived from the values-based arguments for intervention, such as the desirability of assisting allies or alleviating a humanitarian crisis), these facets of ‘rightful’ international conduct are not demarcated by fixed boundaries.Footnote 22 Even in the context of the Kosovo intervention, the Blair Government might have wrapped the UK's involvement in the rhetoric of legitimacy, but it also advanced response to a humanitarian catastrophe as a legal basis for action.Footnote 23 The subsequent machinations surrounding UNSC Resolution 1441Footnote 24 as a legal basis for the Iraq War in 2003Footnote 25 show the continuing importance of building a legal (and not simply political or moral) case for UK military action.
When the UK has sought to use force without a clear basis under the Charter these examples indicate that the Government has placed a premium on constructing plausible ‘legalised’ grounds for action. Inconvenient international law strictures needed to be weakened as a corollary of these efforts. Throughout his time in office Tony Blair maintained that a ‘reconsideration’Footnote 26 of the UNSC's role was necessary and warned that he could not contemplate the escalation of perceived threats to peace and security when ‘the UN – because of a political disagreement in its Councils – is paralysed’.Footnote 27 Within the UK's dualist legal order, international law was presented as more malleable than domestic law, no matter how firmly established the specific rules on the use of force.Footnote 28 This combination of questioning the UNSC's role and positing alternate bases for the use of force was not intended to substitute legitimacy for legality, but to give an action enough of a flavour of international legality to generate a base of support amongst domestic actors. UK Government circles internalized the lesson from these events that a case for military action couched in legalized language and approved by authoritative figures like the Attorney General could make an action appear sufficiently legitimate to neutralize some domestic opposition.
The shift towards a legalized (as opposed to legal) basis for war is not simply some rhetorical ruse; it signals a deeper transformation in the use-of-force discourse. Legalized arguments and political and moral legitimacy claims provide a mutually-reinforcing cycle. In the context of our UK case study this discourse can be seen at work in the recent UK Parliamentary debates over intervention in the Middle East and the Maghreb. The summary of the Attorney General's advice published prior to the 2013 Syria-intervention debate parsed the relevant international law. It focused upon intervention's potential for ‘deterring and disrupting’Footnote 29 the use of chemical weapons by the Assad regime, but referred to the absence of a UNSC mandate only obliquely, in stating that the ‘UK is seeking a resolution … which would … authorise member states … to take all necessary measures to protect civilians in Syria’.Footnote 30 Little over a year later, Prime Minister David Cameron insisted that a military response to the rise of Islamic State (ISIS) in both Iraq and Syria would be legal on the basis of self-defence concernsFootnote 31 generated by the return of UK-resident ISIS fighters, and the need to protect refugees and minority communities.Footnote 32 In the event, only a deployment in Iraq, which had requested assistance, was subject to a vote, but through such claims the Government was attempting to establish a legalized basis for a more extensive action should the issue be revisited. Although UNSC inaction has overshadowed many of these parliamentary debates, even when the UK Government has acted, as in the case of Resolution 2249 (albeit not under Chapter VII) on the threat to international peace and security posed by ISIS,Footnote 33 it has maintained its freedom of action with regard to this precedent by declaring that this ‘resolution is not necessary … to justify action’.Footnote 34 By contrast, with regard to action against ISIS in Syria, the Prime Minister has characterized the Commons' support for UK action as being so significant that he would not hold a vote ‘if there is a danger of losing it’.Footnote 35 These examples showcase the UK Government attempting to generate legitimacy for an action through superficially plausible, even if far from orthodox, legal explanations of the use of force. If the Commons accepts these claims, and authorizes such an action, a necessary degree of domestic political legitimacy will attach to an action.
When Parliament is swayed by legalized language, it generates a precedent which makes support for future actions easier to secure. As with executive practice, domestic assemblies can contribute to the State-practice basis for customary international law.Footnote 36 In theory, therefore, a legislature's acceptance of non-Charter-based justifications for military force could contribute to the legality of such an action. When a legislature has been democratically elected, its authorization of a use of force poses a challenge to the basis of international institutions’ authority.Footnote 37 As such, ‘democratic’ authorization can be used to silence or marginalize ‘“peace through law” enthusiasts.Footnote 38 In the post-9/11 era, the Bush Administration used such reasoning to deny the authority of international institutions.Footnote 39 The converse of this process is readily identifiable; international institutional activity regularly impacts upon the domestic legitimacy of conflict decisions. Resolution 1973 authorizing the 2011 intervention in LibyaFootnote 40 played an important role in legitimating the US engagement even in the absence of specific congressional approval for the deployment.Footnote 41 In the UK, Prime Minister David Cameron similarly harnessed ‘the legitimising power of the Security Council to win … parliamentary support’.Footnote 42 In contrast to democratically-elected domestic assemblies, UN mechanisms are susceptible to critique on the basis of their so-called democratic deficit.Footnote 43 Claims that domestic assembly authorization can enhance the international legal legitimacy of an intervention are therefore difficult for the UNSC to resist, but a lack of resistance to these claims creates obvious dangers.
III. THE EXTERNAL DIMENSION: SIDESTEPPING THE UNSC
The panoply of legal arguments advanced by States regarding the use of force during and since the 2011 intervention in Libya evidences their eagerness to develop novel, non-Charter-based legal avenues for military action. The UK's invocation of humanitarian intervention and self-defence illustrates this shift, and so in this section we examine the UK's changing approach to these doctrines. For our purposes self-defence covers any effort to justify an action under Article 51 of the Charter, which permits States to use force without Chapter VII authorization.Footnote 44 Humanitarian intervention is understood as the military involvement of one or more States in another State without its consent or UN authorization for avowedly altruistic purposes, such as protecting civilians from serious human rights abuses by the State or by forces which the State is unable or unwilling to control.Footnote 45 This formula adopts a State-centric approach to the global legal order.Footnote 46
States have long invoked humanitarian grounds for intervention even when other means of addressing a situation remained open. The pre-Charter era saw numerous supposedly-altruistic interventions.Footnote 47 Pre-Charter debates over interventions were often internal to the intervening powers, especially when the interests of other powerful States were not in question. The value of these interventions as precedents for action did not survive the Charter, which constrains the use of force using Westphalian conceptions of State sovereigntyFootnote 48 and by the power relations between the UNSC's five permanent members.Footnote 49 A direct reading of the Charter's terms, reinforced by the 1970 UN General Assembly Declaration on Friendly Relations,Footnote 50 treats recourse to force as legal if undertaken in self-defence, collective or individual, or under the auspices of Chapter VII resolutions. Outside these confines use of force by States is prima facie illegal, although episodes such as ‘Uniting for Peace’ indicate the possibility of alternate bases for UN-authorized action.Footnote 51
The UK's impatience with the confines of the Charter has a dark history stretching back to the Suez Crisis.Footnote 52 Prime Minister Anthony Eden declared that no UK Government could ever be expected to give Parliament an absolute ‘pledge or guarantee’ that the UK would only use force under a UNSC mandate.Footnote 53 As the Leader of the Opposition responded, the operative question was rather whether the use of force was authorized by the Charter, given that Article 51 permitted action in self-defence without UNSC approval.Footnote 54 Threatening resignation if the Government continued to present the Suez intervention as abiding by international law, the Law Officers maintained that it was ‘difficult if not impossible to find any legal justification for our actions’.Footnote 55 Charlotte Peevers argues that the Suez debacle not only ended Eden's premiership, but also his approach to the UN within UK policy making.Footnote 56 If Eden had regarded the UN as a mechanism for Great Power management of global affairs,Footnote 57 his legal advisers and domestic public opinion instead regarded the Charter as ‘embedding peace through law’.Footnote 58 UN mechanisms would, at least for a time, become central to UK policy on the use of force,Footnote 59 with its position as a permanent UNSC member being used to restrict recourse to force by its Cold War rivals.Footnote 60 Official discussions over the 1970 Declaration on Friendly Relations, for example, regarded the Charter as a basis for denouncing the Brezhnev Doctrine interventions between Warsaw Pact States.Footnote 61
All of the Permanent Five have wielded their UNSC veto to deny the existence of threats to international peace and security or to prevent intervention in response to such threats.Footnote 62 Nonetheless, since the Cold War such activity has generated increasing frustration with the UNSC system.Footnote 63 It has incentivized efforts to find alternate legal bases for action, even if the UK Law Officers had denied their existence during Suez. The Charter's recognition of self-defence as a basis for the use of force without UNSC authorization has provided one avenue for action, and State practice under this ground has become increasingly controversial. The invocation by several Attorneys General of the Caroline Case Footnote 64 places the UK within the imminent-attack school, by which a State does not have to wait for an armed attack to occur, but can strike first when such an attack is clearly anticipated and immediate.Footnote 65 Lord Goldsmith's advice regarding the 2003 Iraq War positions the UK as accepting a right to anticipatory self-defence, but also distanced the UK from the pre-emptive ‘Bush Doctrine’, which permits a response to a threat which is more remote in time and location.Footnote 66
The US' employment of the ‘unwilling or unable’ doctrine has also been controversial. Although most commentators argue that it has yet to become part of customary international law,Footnote 67 in 2015 Australia and Canada utilized it within the context of their claims to be acting against ISIS in Syria under self-defence.Footnote 68 The most significant change to self-defence has come about since 2001, in the form of the potential for non-State actors to fall within Article 51. Previously it was accepted that only State-based armed attacks qualified. This has arguably been extended to include non-State actors such as al-Qaeda and ISIS, though such a change to customary international law remains contested.Footnote 69 All the same, the need to conform to the Charter, demonstrated by States notifying the UNSC of a use of self-defence and by the UNSC's capacity to affirm the existence of a threat to international peace and security to which a response is required, remains significant in States' actions. Such factual determinations by the UNSC are becoming increasing significant when States seek to take action against terrorist threats.
That the Charter does not expressly prohibit humanitarian intervention, and that in certain circumstances such action might address some of the Charter's underlying objects and purposes, are the tenuous grounds often relied upon by that doctrine's proponents.Footnote 70 Although articles of the Charter have been reinterpreted in light of customary international law,Footnote 71 a State's ability to control its internal and external affairs, or to consent to ceding control, remains paramount.Footnote 72 The International Court of Justice (ICJ) moreover maintained, in the Nicaragua Case, that the UNSC has primary (but not exclusive) authority on the use of forceFootnote 73 and further, that there were to date no working examples of humanitarian intervention.Footnote 74 The UK's 1984 Foreign and Commonwealth Office (FCO) Policy Document provides one of the clearest State articulations, concluding that ‘the best case that can be made in support of humanitarian intervention is that it cannot be said to be unambiguously illegal’.Footnote 75 The FCO further highlighted the uncertainty surrounding existing State practice:
[H]istory has shown that humanitarian ends are almost always mixed with other less laudable motives for intervening, and often the ‘humanitarian’ benefits of an intervention are either not claimed by the intervening state or are only put forward as an ex post facto justification of the intervention.Footnote 76
Some Charter violations could be linked to humanitarian crises (including India's intervention in East Pakistan,Footnote 77 Vietnam's intervention in CambodiaFootnote 78 and Tanzania's intervention in UgandaFootnote 79). But despite the subsequent reliance on these examples by humanitarian intervention's proponents, intervening States often recognized that they were acting illegally and rarely, if ever, employed humanitarian intervention as a justification.Footnote 80 General Assembly resolutions on the use of force, provide no support for humanitarian intervention and the vast majority of States continue to deny its existence.Footnote 81
The post-Cold War era saw increasing debate over the doctrine of humanitarian intervention.Footnote 82 Whilst the US, UK and France did not invoke a stand-alone right to humanitarian intervention during the 1991 enforcement of no-fly zones over Iraq, preferring to rely on a very broad interpretation of UNSC Resolution 688, the mixing of multiple basis for use of force would become more prominent. In particular, assertions of apparent UN authorization would become a hallmark of US State practice.Footnote 83 The basis for UK involvement was less than clear. Whereas one minister maintained that ‘[i]t is difficult and probably undesirable to lay down rules concerning a right to intervene’,Footnote 84 the FCO Legal Adviser Anthony Aust subsequently informed parliamentarians that the no-fly-zone operations had been based not on UNSC Resolutions, but on humanitarian intervention.Footnote 85 While admitting that this doctrine had no agreed definition, Aust gamely articulated his account of the necessary criteria for invoking the doctrine: first, the intervening State must consider there to be a compelling and urgent situation of extreme humanitarian distress; second, the affected State would have to be unwilling or unable to address such distress itself; third, a lack of practical alternatives to intervention; and fourth, any action by the intervening State should be limited to the time and scope necessitated by the crisis.Footnote 86 Aust, however, subsequently asserted that most precedents for humanitarian intervention related to the protection of nationals abroad, an entirely separate issue under international law.Footnote 87 In the early 1990s the UK position on humanitarian intervention was therefore characterized by confusion over the grounds for invoking the doctrine, compounded by both reliance upon irrelevant precedents and scant consideration for how to evidence the basis for an intervention before domestic and international fora.
Even though the US and UK's main legal argument at the time of NATO's 1999 operations in Kosovo was implied authorization under UNSC Resolutions 1199 and 1203, UK policymakers continue to rely upon Kosovo as an example of State practice supporting the doctrine of humanitarian intervention.Footnote 88 Although Prime Minister Tony Blair's administration did employ humanitarian intervention rhetoric, placing it within its new approach to international community,Footnote 89 but this departure from previous FCO policy was not without historical revisionism. Following the Kosovo intervention, Foreign Secretary Robin Cook asserted that since 1989 there is an ‘obligation to recognise that the international community does have a right to intervene where the sovereign State is permitting or practising genocide or gross humanitarian violations.Footnote 90 He later developed this claim:
First, any intervention is by definition a failure of prevention. Force should always be the last resort; second, the immediate responsibility for halting violence rests with the state in which it occurs; but, third, when faced with an overwhelming humanitarian catastrophe and a government that has demonstrated itself unwilling or unable to halt or prevent it, the international community should act; and finally any use of force in this context should be collective, proportionate, likely to achieve its objective, and carried out in accordance with international law.Footnote 91
Cook insisted that humanitarian intervention ought to be undertaken in line with the rule of law and alongside international partners. Critically, from the perspective of domestic debates, these qualifications point towards collective action rather than an individual State's ‘right’ to invoke humanitarian intervention.Footnote 92 Parliament's Foreign Affairs Committee was unmoved by these claims, asserting that the Kosovo operation ‘was contrary to the specific terms … of the UN Charter’Footnote 93 and that ‘the doctrine of humanitarian intervention has a tenuous basis in current international customary law … [which] renders NATO action legally questionable’.Footnote 94 In response the Government welcomed the Committee's acknowledgment of its efforts to obtain a clearer UNSC mandate, but high-handedly and curiously given the Executive's later reliance on Parliamentarians, concluded ‘that disputes about international law are not ones that the Committee can resolve’.Footnote 95
Kosovo provides a dubious basis for claims of a change in State practice. NATO was vague in its justifications, and certainly did not directly claim a right of humanitarian intervention, referring obliquely to the need to respond to humanitarian catastrophes.Footnote 96 Most NATO States justified their intervention by reference to ‘implied authorisation’ under UNSC Resolutions. France, the Netherlands and Slovenia explicitly drew upon the UNSC's acceptance under Chapter VII that events in Kosovo constituted a threat to international peace and security, even though both China and Russia's strongly opposed the suggestion that this provided a basis for NATO's action.Footnote 97 In the subsequent ICJ case, instigated by Serbia, there was scant reliance upon the supposed right of intervention.Footnote 98 Dismissed at the provisional measures stage, only Belgium provided substantive legal grounds justifying intervention. These justifications centred upon implied authorization, noting the UNSC's rejection of Russia's draft resolution condemning the intervention.Footnote 99 Humanitarian intervention was raised only as an ancillary argument. India, Tanzania and Vietnam's historical interventions were erroneously invoked as examples of relevant State practice.Footnote 100 Serbia, by contrast, maintained that there was no right of intervention.Footnote 101
In spite of the UN Secretary-General reiterating the UNSC's centrality within the international security system,Footnote 102 the Kosovo intervention has been drawn upon as a model for circumventing the Charter. Although Germany at the time denied that Kosovo set a precedent for future action, the then German Chancellor, Gerhard Schroeder, has subsequently claimed that NATO's actions in Kosovo provided a precedent for Russia's intervention during the Crimea Crisis; ‘[w]e sent our plan[e]s to Serbia and together with the rest of NATO they bombed a sovereign State without any UN security council backing’.Footnote 103 Other NATO States also relied upon the failure of diplomatic efforts as a justification for military action.Footnote 104 Again, such claims would subsequently resurface in the context of proposed military action against the Assad regime in Syria in response to its use of chemical weapons in 2013, with UNSC members which supported intervention characterizing it as a last resort to prevent humanitarian catastrophe after the failure of all diplomatic efforts. China, by contrast, viewed events in Syria as an internal matter and emphasized Article 2.4 of the Charter.Footnote 105
The development of responsibility to protect (R2P) provides a legal basis for intervention where States are unwilling or unable to protect their own citizens.Footnote 106 R2P recognizes that States owe a broad range of duties to protect their populations and after a failure to do so the international community may take collective action to protect populations within the Charter's terms.Footnote 107 This doctrine, which Kofi Annan envisaged as forestalling action without UN authorization,Footnote 108 undermines claims that a right of humanitarian intervention has emerged over the past two decades.Footnote 109
This section has demonstrated the UK's wide array of legal justifications for uses of force in recent decades. Even when doctrines like humanitarian intervention have grabbed headlines, they have never stood alone as credible legal bases for action. In some supposed instances of legal humanitarian intervention, Chapter VII UNSC Resolutions have fully authorized the use of force. In other cases, they have been relied upon as providing implied authorization or as establishing the factual scenario of a threat to international peace and security. Self-defence, either collective or individual, has in many respects become as controversial a basis for action as humanitarian intervention. The US and UK have asserted that Article 51 of the Charter grants States a very broad remit to decide when to invoke self-defence, provided they report their action to the UNSC. As Christine Gray argues, this ‘lip-service’ to the basis of self-defence risks dressing up uses of force in a ‘veneer of legality’.Footnote 110 Justifying uses of force based upon a concoction of grounds ‘boils with the danger of abuse’,Footnote 111 particularly if such a case is constructed with the aim of swaying the opinion of domestic legislators.
IV. THE INTERNAL DIMENSION: THE UK PARLIAMENT'S EXPANDING ROLE IN USE OF FORCE DECISIONS
The path towards the adoption of a constitutional convention whereby the House of Commons will be consulted on military action and thereby provide democratic oversight of the use of force begins in the nineteenth century, before the UK's governance arrangements became truly democratic. AV Dicey's contradictory interpretations of the UK war prerogative illustrate how difficult it would be for the Commons to develop an oversight role. Initially, Dicey explained that as a prerogative power, ‘it is not Parliament, but the Ministry, who … virtually decide all questions of peace or war’.Footnote 112 This position aligned with William Blackstone's account, whereby royal (executive) powers were deliberately excluded from Parliament's purview ‘for the sake of unanimity, strength, and dispatch’,Footnote 113 traits not always associated with parliamentary deliberation. Dicey was, however, writing in an era where representative politics were gaining importance. Even with his distrust of democracy, he appreciated that he could not simply recite that executive discretion over conflict decisions remained unfettered. He therefore qualified his claims regarding the prerogative, asserting that these powers were ‘exercised by a Cabinet who are really servants, not of the Crown, but of a representative chamber which in its turn obeys the behests of the electors’.Footnote 114
In the early twentieth century ‘democratic’ control of foreign policy often seemed far removed from political reality. When the opposition contemplated a censure motion regarding the conduct of the Boer War, its own MPs expressed a widely held view that Parliament was ‘a consultative body’ on military affairs; ‘[i]t can stimulate or it can paralyse action, but it cannot direct it’.Footnote 115 Parliamentarians' powerlessness was compounded by a lack of access to information. Ministers alone were able to draw upon the advice of professional diplomats, leading James Bryce to encourage MPs to grant the executive considerable latitude in foreign affairs:
[T]he foreign relations of modern states are so numerous and complex … that … even democratic countries like France and England are forced to leave foreign affairs to a far greater degree than home affairs to the discretion of the ministry of the day.Footnote 116
During his time at the Foreign Office, Sir Edward Grey operated under the oversight not of Parliament, nor even of the Cabinet, but of ‘a small group of Ministers who received all … important dispatches’.Footnote 117 Grey stoked parliamentarians' uncertainties over foreign affairs,Footnote 118 warning them of the perils of foreign policy conducted against a backdrop of ‘constant criticisms of individual Members of the House’.Footnote 119 Answers to foreign policy questions were frequently opaque or were refused for reasons of security.Footnote 120 Grey was not, however, averse to having his cake and eating it too, informing the French Ambassador that ‘he could promise nothing to any foreign power’ which would not receive Parliament's ‘whole-hearted support’.Footnote 121 Subjection to ‘[a] long course of the Grey treatment’Footnote 122 saw some MPs bridle at their marginalization and call for a dedicated Foreign Affairs Committee with access to diplomatic briefingsFootnote 123 to strengthen parliamentary expertise and thereby enhance scrutiny.Footnote 124 These calls long went unheeded.Footnote 125
Short of a censure motion,Footnote 126 Parliament's avenue for constraining the use of force lay in its control over government spending,Footnote 127 given the extraordinary costs associated with military campaigns.Footnote 128 Radical Liberals did force votes over foreign-policy-related censure and supply motions in the years preceding the First World War, but these were roundly defeated.Footnote 129 Amidst the fraught diplomacy of July 1914, as the Cabinet fractured over whether the UK should intervene in the event of a continental war,Footnote 130 parliamentarians remained slow to express public dissent. Late that month, in a scheduled debate on UK naval spending, the Commons followed the entreaties of Conservative MP Charles Beresford, a leading critic of the UK's foreign policy, that it would ‘be most unpatriotic under the circumstances abroad for anyone to make a drastic criticism showing up the weak points in our naval policy at the present moment’.Footnote 131 For all of this weakness, however, when Grey came before Parliament on the eve of war, even though no vote was called, in a real sense he was seeking the authority of the Commons. He outlined the Government's view of international relations and law, and put before MPs the circumstances in which he believed the UK would be drawn into conflict. A short debate ensued in which the leaders of the major parties assented.Footnote 132 That a vote was not needed speaks to the inevitability of the outcome.Footnote 133 To this day, Grey's speech remains dogged by controversy, with his critics arguing that Parliament committed the UK to war on the basis of a partial rendering of the events precipitating the conflict.Footnote 134
Parliament's response to the First World War set the tone for its subsequent engagement with the war prerogative. As a matter of law, there may have been no requirement for Parliament's prior permission for the use of force,Footnote 135 but even before 1914 some actors were beginning to speak of a ‘constitutional’ need to involve Parliament.Footnote 136 After the war, such involvement would ordinarily be limited to a government's ‘informal consultation with Parliament’,Footnote 137 whereby ministers outlined official policy in an unamendable adjournment motion and invited parliamentary discussion (with the potential risk of censure being constrained by the party whip). By this process Parliament considered, often ex post facto, exercises of the war prerogative and gave tacit approval to twentieth-century military interventions.Footnote 138 Its involvement was intended to scrutinize and ultimately legitimate UK policy, to inform the general public, and also to prevent the accumulation of societal tensions by airing different viewpoints on the decision to use force.Footnote 139 Often these arrangements meant that the Commons would find itself presented with a ‘done deal’ by ministers;Footnote 140 circumstances it would be internationally humiliating for MPs to question the Government's policy.Footnote 141 Even as the mystique surrounding the Foreign Office waned in the aftermath of the First World War,Footnote 142 ministers would continue to provide deliberately vague answers to parliamentary questions regarding military operations.Footnote 143
Into the Charter era, the necessities of the Cold War thwarted any development of Parliament's oversight of war powers. Against the backdrop of potential nuclear war, the Ministry of Defence protocol on military deployments warned that ‘almost every military move or alert is a subject of public concern and comment’.Footnote 144 When no one could tell whether a proxy war might ignite a wider conflict the watchwords became executive freedom, and ‘any argument about whether Parliament should insist on giving prior approval to a war becomes farcical’.Footnote 145 Even in the lead-up to the 2003 Iraq War debate the Attorney General maintained that it would ‘be lawful and constitutional for the Government, in exercising the Royal Prerogative … to engage United Kingdom forces in military action without the prior approval of Parliament’.Footnote 146 The most extensive claim that could be made of this history of ‘democratic oversight’ within the UK is consequently subject to extensive caveats; ‘there has not been a significant armed conflict overseas since the beginning of the 20th century in which the United Kingdom has been involved where, in one way or another, at the time of decision or in retrospect, this House has not indicated whether, and in what way, it has consented to the Executive decision taken’.Footnote 147
If the Cold War ossified the form of Parliament's involvement in use-of-force decisions, the Charter's provisions did at least change the focus of its scrutiny.Footnote 148 Although some MPs noted Parliament's limited role in foreign affairs in the Charter ratification debate,Footnote 149 through the second half of the twentieth century parliamentarians paid increasing attention to UNSC activity. Other than instances such as the Falklands War, where the UK's actions were explained by reference to self-defence,Footnote 150 the bright-line nature of the Charter's restrictions meant that from the Korean War onwardsFootnote 151 it became standard practice for ministers to refer to authorizing UNSC Resolutions in motions seeking parliamentary support for military interventions. The effect of the lack of such a Resolution is exemplified by the heated debates over the 1956 Suez CrisisFootnote 152 and the 2003 Iraq War.Footnote 153 But even in the latter context, the motion before Parliament sought to clothe the UK's use of force on the pretext of destroying Iraq's supposed stockpiles of Weapons of Mass Destruction in the UNSC's authority; ‘the opinion of the Attorney General that, … Iraq being at the time of Resolution 1441 and continuing to be in material breach, the authority to use force under Resolution 678 has revived and so continues today’.Footnote 154 Parliament supported this motion by 412 votes to 149.
The Iraq War debate and vote were at the time presented as major concessions by the Blair Government. Previously, control of foreign affairs under the Royal Prerogative and arguments that any substantive parliamentary dissent towards UK policy ‘might be exploited by the adversary as evidence of division and hence weakness’Footnote 155 had enabled ministers to avoid such set-piece debates and votes. The Blair Government's change of approach from its practice at the outset of the interventions in Kosovo, Sierra Leone and Afghanistan, was not without benefit to the administration. The UK Government enjoys marked advantages in the Commons as opposed to the UNSC in its efforts to legitimate the use of force. Opposition to military action which a Government advocates as being in the national interest can be cast as unpatriotic in time of crisis. Fear of this label had so affected the Labour Party at the time of its opposition to the Suez intervention that even after its success in the 1964 General Election it refused to institute an inquiry into the Crisis.Footnote 156 Despite the concerns he expressed before Parliament over the Iraq War, then Conservative Leader Iain Duncan Smith nonetheless brought the bulk of Conservative MPs to support the action on the basis that ‘when the Government do the right thing by the British people, they deserve the support of the House’.Footnote 157 Party loyalty can also be exploited to keep the Government's own backbench MPs in line with its position on military force,Footnote 158 which Tony Blair played up to by suggesting that he would resign if defeated.Footnote 159 Moreover, notwithstanding the inherent difficulty with isolating legal issues from the wider context of international relations,Footnote 160 the nature of Commons debate precludes authoritative legal or security assessment, leaving parliamentarians beholden to summaries of the advice enjoyed by the Executive. In the context of the Iraq War both the intelligence basis for warFootnote 161 and the summary of the Attorney General's legal advice provided to Parliament were seriously deficient.Footnote 162 In the final assessment, a parliamentary authorization of a use of force remains a political assessment drawing upon national interest and moral considerations as well as issues of lawfulness. MPs might therefore accept (as some arguably did in the context of Iraq) an action as legitimate notwithstanding a breach of international law.Footnote 163 Exploiting these advantages, the Blair Government harnessed the legitimating force of Parliament's vote on the use of force to draw attention away from the lack of a clear basis for military action under international law.
V. COMBINING THE INTERNAL AND EXTERNAL APPROACHES
The importance of the 2003 Iraq War to the UK's overarching approach to the use of force can nonetheless be overstated. This conflict did not witness the creation of a constitutional convention requiring that the House of Commons be consulted over future uses of force. When the courts thereafter heard challenges to the legality of the invasion, no judges spoke of adjusting their approaches in light of a developing convention. At best, the Gentle Footnote 164 jurisprudence pointed to the hazy nature of democratic oversight of UK military action, as seen in Lord Hope's assertion that the lawfulness of the invasion was ‘a matter for … which ministers are answerable to Parliament and, ultimately, to the electorate’.Footnote 165 On becoming Prime Minister, Gordon Brown pledged enhanced parliamentary oversight of the use of force.Footnote 166 The Brown Government supported claims that the Iraq vote had set a precedent regarding the Commons approval of military action,Footnote 167 but did not have cause to act upon this pledge. The Iraq War vote could well have been an aberration, had it not been for the chastening impact of the subsequent ‘ill-fated occupation of the country’Footnote 168 and Prime Minister David Cameron's consequent eagerness to distance his administrations’ repeated uses of force from the Blair Government's practice. Cameron's administrations have intertwined the enhancement of Parliament's role in approving military actions (the internal shift in UK use-of-force processes) with the already-established trend of advancing novel grounds for action in international law (the external aspect of how the UK approaches the use of force). The UK's responses to the collapse of the Libya, the Syrian Civil War and the rise of ISIS have involved the official invocation of almost every conceivable legal justification for the use of force before the Westminster Parliament. Although each successive vote has hardened the constitutional convention that Parliament will be consulted on uses of force, we will see that little has been done to strengthen the Parliament's capacity to meaningfully scrutinize proposals for military action.
A. 2011 Debate: Use of Force against Qaddafi's Regime in Libya
Following the 2010 general election, the Coalition Government accepted the constitutional force behind Parliament's claims to authority over the 2011 intervention in Libya. As Sir George Young informed the House of Commons:
A convention has developed in the House that before troops are committed, the House should have an opportunity to debate the matter. We propose to observe that convention except when there is an emergency and such action would not be appropriate. As with the Iraq war and other events, we propose to give the House the opportunity to debate the matter before troops are committed.Footnote 169
The Government's acceptance that it was, outside exceptional circumstances, bound to give the Commons a consultative vote on military action was in part a function of its nature as a coalition, and in part a conscious effort by Prime Minister David Cameron to differentiate his approach to conflict from Tony Blair's reluctant acceptance of a vote on the 2003 Iraq War.Footnote 170 According to Rosara Joseph, ministers appreciated that ‘[t]he decision to deploy the armed forces is too important … to leave to the Prime Minister and an inner cabal of government ministers’.Footnote 171 Notwithstanding these drivers, the shift appeared to radically enhance Parliament's role regarding the war prerogative. Few US Presidents, by comparison, would contemplate ‘voluntarily surrender[ing] the discretion that their institutional position provides’.Footnote 172
This change could alternately indicate the Coalition Government's appreciation that trumpeting Parliament's involvement can enhance the legitimacy of conflict decisions. The Young Convention was articulated after the UNSC's unanimous adoption (under Chapter VII) of Resolution 1970, which explicitly cited R2P in demanding ‘an immediate end to the violence’ in Libya.Footnote 173 Just over two weeks later it followed up on this demand upon the Libyan Government, and authorized:
Member States … acting nationally or through regional organizations or arrangements, and acting in cooperation with the Secretary-General, to take all necessary measures … to protect civilians and civilian populated areas under threat of attack …, while excluding a foreign occupation force of any form on any part of Libyan territory . . . .Footnote 174
This Resolution ‘represents the first mandate by the Security Council for a military intervention based on the responsibility to protect against the wishes of a functioning government’.Footnote 175 The resolution represents a clear, and quite prescriptive, Security Council mandate. The resolution specifically excluded occupying forces, while requiring the establishment of a no-fly zone in addition to further diplomatic efforts and military action to protect civilian populations. Indeed, in the Commons debate on the intervention in Libya, Liberal Democrat MP Sir Menzies Campbell confidently asserted that UK action was ‘on much stronger ground’ than previous interventions, including Kosovo, because rather than being predicated on the humanitarian intervention doctrine, ‘the Security Council has said expressly … that “all necessary measures” may be taken’.Footnote 176
Potentially troubling in light of Sir George Young's pledge was that the UK's military intervention in Libya began over the course of the weekend prior to the Commons debate and consultative vote.Footnote 177 However, although Parliament, as so often in the past, was presented with a fait accompli, MPs overwhelmingly backed the intervention.Footnote 178 The Government was generally perceived to have acted properly given the political consensus, clear basis for action in international law and the caveat within the Young Convention allowing it to act in advance of Commons' authorization when responding to an emergency situation. Several MPs expressly accepted that the assault on Benghazi by Colonel Qaddafi's forces would have claimed more civilian lives had intervention been delayed.Footnote 179 Despite the apparent significance of the Young Convention's emergence, however, Nigel White has noted that even in the context of the 2011 intervention, in which the legal basis for action was uncontroversial, ministers still refused to provide ‘the full legal advice necessary for Parliament to make informed decisions’.Footnote 180 Parliament's access to little more than fragmentary legal advice would become a reoccurring feature of subsequent intervention debates. Arguably, the Young Convention's effect was to enhance Parliament's formal role without strengthening the substantive effect of its scrutiny, which would become apparent in the subsequent debates.
B. 2013 Debate: Use of Force against the Assad Regime in Syria
By the summer of 2013, the Syrian Civil War had spawned a humanitarian crisis that spilled into Turkey, Lebanon, Jordan and Iraq. In August, the use of chemical weapons near Damascus dramatically heightened the possibility of direct intervention by outside powers. The UNSC condemned the attack, albeit without apportioning blame.Footnote 181 Although R2P appeared to fit such circumstances, Russia's continued support of the Assad Regime prevented the UNSC from authorizing such action. The UK Government therefore sought Parliament's support for military action against Assad's forces, not as an adjunct to UNSC authorization, but in lieu of any operative resolution.Footnote 182
In contrast to the Libya intervention, the 2013 Syria debate took place before force was employed.Footnote 183 This was no accident, for before Parliament's summer recess MPs concerned with the Government's intentions had passed a motion requiring that ‘no lethal support’ would be provided against President Assad's forces ‘without the explicit prior consent of Parliament’.Footnote 184 Despite the Government's ability to plausibly claim that the chemical weapons attack constituted an emergency requiring prompt response, as it had in Libya, Prime Minister David Cameron recalled Parliament. This development, and the Government's adherence to the outcome of the vote, indicate that ministers regarded themselves as obliged to follow the constitutional convention that they had invoked two years earlier.Footnote 185 For the Political and Constitutional Reform Committee, these actions meant that outside exceptional emergency circumstances, Parliament must express its opinion on a use of force prior to the UK's involvement.Footnote 186 Carsten Stahn has therefore argued that the ‘greater involvement of parliamentary control over executive action may be one of the ‘‘gains’’ of the Syrian crises’.Footnote 187 When Parliament authorizes military force, its consideration of action's legality is, however, bound together with deliberation upon an action's morality and whether ‘it is a politically or militarily sensible operation’.Footnote 188 Requiring the UK Parliament to make such determinations has transformed it into one of the decision-making fora regarding the use of force, bringing such decision-making closer to the influence of domestic constituent actors. At issue, however, is whether such activity can displace the UNSC's role.
In his legal advice, published in summary form to bolster the Government's case for action, the Attorney General Dominic Grieve asserted that ‘[i]f action in the Security Council is blocked, the UK would still be permitted under international law to take exceptional measures in order to alleviate the scale of the overwhelming humanitarian catastrophe in Syria’.Footnote 189 His advice had two limbs. The first was that use of force by the UK is not necessarily predicated upon UNSC authorization and the second explained the circumstances which would trigger the UK's supposed right to intervene by force in another State for humanitarian purposes.Footnote 190 The first limb was predicated upon parliamentary affirmation supplying the necessary democratic authority for an action, thereby displacing the need for UNSC input.Footnote 191 The implication of the advice is that such domestic activity can and should impact upon an action's international legality.Footnote 192 From being mooted as a potential avenue by which to provide ‘extra democratic legitimacy to military action’ after the Kosovo intervention,Footnote 193 the 2013 Syria crisis saw ministers treat Parliament as the only forum necessary for legitimating UK humanitarian intervention. The pace of this change should give reason for pause. The Government's Syria motion pushed Parliament to the fore because of the UNSC's failure ‘over the last two years to take united action in response to the Syrian crisis’.Footnote 194 That this flattery failed to overcome MPs’ concerns over intervention should not obscure the Government's concerted effort to marginalize UN institutions.
Many MPs showed some understanding of international law's requirements regarding the use of force, with some affirming the importance of the UN.Footnote 195 Some, however, readily accepted that interventions can be justified on the basis of a post-Charter paradigm, swathed in the Attorney General's reassuring legalese. As one Labour MP stated:
I am, by instinct and nature, a humanitarian interventionist. I support the responsibility to protect. … I believe that there are sometimes circumstances where it is right to take action without a United Nations Security Council resolution.Footnote 196
Such statements, eliding the distinct concepts of humanitarian intervention and R2P,Footnote 197 highlight the risks inherent in the move towards parliamentary authorization. The Government endeavoured to win parliamentarians over to humanitarian intervention by playing upon frustrations with UN processes which were, after all, designed to stymie opportunities for a State or group of States to intervene in the affairs of another by force.
Having set out the UK Government's position that the UNSC is, in certain cases, dispensable, Attorney General Dominic Grieve's advice proceeds to lay down a test for the legal use of force in response to an ‘overwhelming humanitarian catastrophe’.Footnote 198 He advanced three prerequisites for invoking humanitarian intervention:
(i) there is convincing evidence, generally accepted by the international community as a whole, of extreme humanitarian distress on a large scale, requiring immediate and urgent relief;
(ii) it must be objectively clear that there is no practicable alternative to the use of force if lives are to be saved; and
(iii) the proposed use of force must be necessary and proportionate to the aim of relief of humanitarian need and must be strictly limited in time and scope to this aim (i.e. the minimum necessary to achieve that end and for no other purpose).Footnote 199
These grounds for intervention pay little attention to the relevant international law.Footnote 200 The test, set out in a highly legalized form, purportedly provides a pragmatic formula for interventions, but is unconvincing regarding the necessary evidence-base. The test relies on the UK Government's conclusion that the ‘international community’ accepts that a humanitarian crisis is ongoing, but foists the factual assessment upon domestic legislators (regardless of their capacity to perform this task).Footnote 201 Philippe Sands questions Parliament's ability to conduct such an analysis in the context of the 2013 debate, especially when ‘the assertions by the Prime Minister did not appear to be an accurate summary or account of the legal advice received, and in this way had the effect of misleading Parliament’.Footnote 202 The notion of ‘general acceptance’ within the international community of circumstances requiring urgent action attempts to discount the opposition of Russia and China to intervention in the UNSC. As such, the only States that matter under this test are liberal-democratic States which accept the possibility of lawful humanitarian intervention. Russell Buchan has suggested that an operative international community might indeed be confined in this wayFootnote 203 and that some States' opposition to humanitarian intervention could therefore be ‘dismissed as illegitimate’.Footnote 204 The 2013 chemical weapons crisis highlighted the weaknesses in this proposition. Russia maintained that good-faith negotiations were capable of resolving the specific chemical weapons crisis and was able to use its leverage with the Assad regime to respond to the US and UK position that Syria could address their concerns by verifiable destruction of all such weapons.Footnote 205 The subsequent UNSC activity and destruction of Syrian chemical weapons removed this issue as a basis for urgent action.Footnote 206
US and UK assertions of a right of humanitarian intervention have been described by Harold Koh as an ‘evolution’ within international law.Footnote 207 Loose talk of evolution, however, avoids discussion of the necessary elements for the alteration of customary international law; State practice and opinio juris. Koh is effectively presenting these States' internal discussions as sufficient to constitute State practice. Although official legal advice can evidence State practice,Footnote 208 other States would not ordinarily comment upon it, as they would with State actions, meaning that it should be treated with considerable caution.Footnote 209 Koh's claims are supported by Sir Daniel Bethlehem, former FCO Legal Adviser, who asserted that strict application of Article 2.4's prohibition on aggressive war would be ‘simplistic’, and argued that the Commons' rejection of intervention did not challenge the lawfulness of humanitarian intervention as the debate had focused on the ‘wisdom of intervention, not on its legality’.Footnote 210 The latter claim is dubious in light of the specific focus on questions of legality by many of the contributions to the debate, but the former assertion points towards Bethlehem's acceptance that, despite the Charter's clear terms, domestic assemblies' decisions can affect the legality of military force under international law.
In empowering Parliament, Prime Minister David Cameron's administrations have been less concerned with enhancing oversight of the war prerogative than with shifting the key governance point at which a conflict is legitimated away from the Charter's mechanisms. This shift allows ministers to take advantage of the factors which historically stymied effective Commons' oversight of foreign affairs, including their control of information, their ability to cast the issue in terms of national interest and their command of party loyalty. Whilst going to Parliament does not guarantee such success, as Cameron might have imagined it would, this approach does improve a government's chances of legitimating an action by comparison to the UNSC route. When Parliament rejected the motion to authorize the use of force,Footnote 211 the Prime Minister accepted that the Government could not use the prerogative to involve the UK military in the Syrian conflict against Parliament's wishes.Footnote 212 After this chastening experience, however, ministers have been able to make even more persuasive claims as to the weight of Parliament's input.
C. 2014 Debate: Use of Force against ISIS in Iraq
In 2014, the conflict in Syria spilled into neighbouring Iraq as ISIS suddenly seized a swathe of territory in both countries. Unable to contain ISIS, and with Baghdad itself under threat, the Iraqi Government made a ‘specific request’ for air strikes by allied countries to support its efforts at self-defence.Footnote 213 Intervention by invitation is anticipated by the Charter.Footnote 214 The UK could therefore respond to the Iraqi Government request for support without drawing upon any controversial legal basis for action, and Parliamentary support for action against ISIS in Iraq was overwhelming.Footnote 215 Throughout the debate, however, the possibility of wider intervention was advanced, but held in check by the shadow of the Commons' rejection of intervention in Syria a year earlier.
Even before the UK debate, other States, led by the US, had responded to the Iraqi Government's request and were already engaging ISIS targets in Syria. The UNSC had recognized ISIS as part of the broad threat that terrorism posed to international peace and security,Footnote 216 and mandated, under Chapter VII, that States take action to prevent foreign fighters entering Syria. However, it had not authorized the use of force against the group. Resolution 2178 therefore provided no basis for extending operations against ISIS targets within Syria, and President Bashar al-Assad's regime had not given authority for Coalition aircraft to operate within its airspace. The US Government therefore justified its air strikes in Syria through a combination of Article 51, on the basis of its engagement in collective self-defence of Iraq, and the claim that the Syrian Government was ‘unwilling or unable’ to deal with the threat ISIS posed to Iraq.Footnote 217 Although the US had previously employed the unwilling-or-unable doctrine to justify drone strikes and special operations in Pakistan and Somalia, few States endorse this approach. Many of the States involved in the Coalition expressed reservations about this legal basis for action in Syria,Footnote 218 although Canada (in April 2015), Australia (in September 2015), and France (in October 2015) would subsequently extend their air campaigns into Syria.Footnote 219 Turkey began air strikes against ISIS and the PKK in Syria in July 2015, citing its own self-defence concerns.Footnote 220
Despite the published summary of the UK Government's legal guidance on intervention being predicated upon the Iraqi Government's consent, and therefore disclosing no basis for the legality of using force against ISIS in Syria,Footnote 221 Prime Minister David Cameron explicitly told MPs that he saw no barrier in international law to extending the UK's support for the Iraqi Government into Syria.Footnote 222 The Leader of the Opposition, Ed Miliband, accepted that there was ‘a strong argument about the legal base for action in Syria under article 51 [UN Charter]’.Footnote 223 Nonetheless, the Government's decision to seek authority for air strikes in Iraq alone demonstrated the impact of the 2013 debate. Although the Government did display a sudden aversion to intervention in the absence of clear legal grounds, Prime Minister David Cameron still set out some circumstances in which the UK might use force in Syria, even without explicit Commons' authorization:
If there was the need to take urgent action to prevent, for instance, the massacre of a minority community or a Christian community, and Britain could act to prevent that humanitarian catastrophe – if I believed we could effectively act and do that – I am saying I would order that and come straight to the House and explain afterwards.Footnote 224
The Prime Minister did not explain the legal basis for such an intervention beyond the vague need for ‘urgent action’ in the context of ‘humanitarian catastrophe’. The former Attorney General Dominic Grieve, however, maintained that the extension to UK operations against ISIS into Syria would be both legal and legitimate notwithstanding the deadlock in the UNSC:
There is no doubt that [the UNSC] has an important role to play in issues concerning humanitarian necessity, but the Government will at least have to consider whether any application, if it were to come, to the UN for such a resolution has any prospect of success. The ability to intervene, I have no doubt, exists, even if no such resolution is present.Footnote 225
Here, he may have been expanding upon a legal position he had set out a year earlier regarding intervention in Syria, but he was joined by parliamentarians who eagerly expressed their opinion that extending the intervention into Syria would be legal on humanitarian intervention grounds.Footnote 226 The impact of the successive UK Governments' efforts to build up Parliament's role and marginalize the UNSC was therefore bearing fruit in terms of parliamentary support, even if such an intervention was in this instance theoretical.
As ISIS continued to gain territory and adherents in spite of the Coalition air strikes, the UK Government would employ the ‘urgent action’ exception within the Young Convention—not in the context of a humanitarian response, but on the basis of defending against threats to ‘a critical British national interest’.Footnote 227 In early September, Prime Minister David Cameron informed Parliament that the UK had indeed used force in Syria, through a drone strike which killed three ISIS members near Raqqa. The Prime Minister characterized the strike as an emergency response to the threat posed by Reyaad Khan, a UK citizen fighting with ISIS, without which ‘we had no way of preventing his planned attacks on our country’.Footnote 228 The Prime Minister's argument that the drone strike was an imminent necessity to prevent an attack against the UK appears to be an effort to fit the action within Article 51 of the Charter. Indeed, this was the basis on which the UK informed the UNSC of its action—though notably these were not the terms by which Parliament was informed.Footnote 229 Whether a drone strike can be justified under Article 51 involves not simply a claim as to the extent of this provision of the Charter, but requires the UK to establish the legal and factual basis for this claim. Although the Attorney General maintained that such action is possible in response to a planned armed attack by a terrorist group,Footnote 230 the limits of self-defence against a terrorist group under of international law are contested and difficult to fulfil,Footnote 231 and parliamentary oversight of such claims is all but impossible when MPs are not given access even to a document summarizing his legal advice. The Government did not, moreover, provide Parliament with factual evidence indicating the imminence of Khan's threat. In the absence of such evidence the UK could well be characterized as employing the Bush Doctrine of pre-emptive self-defence.Footnote 232 In this strike, then, the Government was trying to gain advantages from utilizing several legal paradigms. It wanted to present the incident as a use of force covered by Article 51 to attempt to avoid the application of international human rights law, but also sought to persuade Parliament that it was a one-off strike not warranting further scrutiny by MPs.
D. 2015 Debate: Use of Force against ISIS in Syria
Throughout 2015, the UK Government maintained that its intention was not simply to respond to specific threats to UK interests but to extend general military action against ISIS into Syria, albeit noting that it needed ‘parliamentary authority’ to do so.Footnote 233 Parliament's refusal to authorize military force against Assad in 2013 ‘loomed large’ over official policyFootnote 234 and ministers maintained that ‘we will not bring a motion to the House on which there is not some consensus’.Footnote 235 There is no doubt that the Government felt bound by the Young Convention, in spite of persistent siren voices that it did not amount to a legal constraint upon action.Footnote 236 For all the attention paid to Parliament, however, the UK Government downplayed the significance of the UNSC. The Defence Secretary styled the UK's failure to undertake air strikes in Syria as ‘morally indefensible’, alluding to the need to defend UK interests against ISIS.Footnote 237 Parliament's Foreign Affairs Committee remained unconvinced, maintaining that UNSC authorization was ‘desirable for more than simply legal reasons’.Footnote 238
Two events changed the debate on intervention; the downing of Metrojet Flight 9268 in October 2015, claimed by ISIS as retaliation for Russia's air strikes in support of the Assad regime,Footnote 239 and the terrorist attacks on Paris two weeks later, which ISIS claimed were a response to French air strikes in Iraq and Syria.Footnote 240 As the attribution of these attacks to ISIS was confirmed, the UK Government stepped up its claims that self-defence provided a legal basis for extending the UK's strikes against ISIS into Syria:
Of course, it is always preferable in these circumstances to have the full backing of the UN Security Council, but what matters most of all is that any action we would take would be both legal and help protect our country and our people right here. As I said yesterday, we cannot outsource to a Russian veto the decisions we need to keep our country safe.Footnote 241
The French Government treated the mass-casualty attacks as an act of war and immediately invoked the European Union's (EU) mutual assistance provision in response to an armed attack.Footnote 242 Rather than sidelining the UNSC, however, the French also reworked a Russian draft resolution into UNSC Resolution 2249.Footnote 243 Agreed unanimously, this Resolution broadens the scope for military action against ISIS. The decision to not invoke Chapter VII, whilst nonetheless making a factual assertion as to the existence of a threat to international peace and security, is a singular development which means that the Resolution could be described as a halfway house towards the authorization of force. Instead of explicitly authorizing force, the Resolution recognizes that ISIS constitutes an ongoing threat to peace and security that is not confined to Iraq and Syria and calls upon States to take all necessary measures to eradicate the safe havens established by ISIS. In doing so, the UNSC is allowing States to claim self-defence, based on a non-territorial threat to international peace and security, under Article 51 when undertaking operations against ISIS targets in Iraq and Syria without having to establish a factual scenario warranting such a response. Resolution 2249 also bolsters arguments that a non-State group can be responsible for an armed attack.Footnote 244
Even with Resolution 2249 in place, the UK Government spent nearly two weeks reinforcing its support within Parliament. First, under the auspices of replying to the Foreign Affairs Committee, the Prime Minister David Cameron set out his case for action, ‘founded on the right of self-defence as recognised in article 51 of the United Nations [C]harter’,Footnote 245 on the basis that ISIS activity ‘has reached the level of an “armed attack”, such that force may lawfully be used in self-defence to prevent further atrocities being committed’.Footnote 246 According to the Prime Minister David Cameron, Resolution 2249 merely ‘underscored’ this basis for action.Footnote 247 Having ascertained reaction to this opening gambit in the House and the country, and confident that a comfortable Commons majority in favour of military action was in hand, the Prime Minister announced a day-long debate and vote.Footnote 248 In the course of this debate, many MPs who had wavered over military action in the preceding months noted the impact of both the changed security situation and the ‘clear and unambiguous’Footnote 249 UNSC 2249 in persuading them to back the Government's motion. Former Home Secretary Alan Johnson stated that whereas the House had been inhibited from supporting action against ISIS outside Iraq ‘by the absence of a specific UN resolution’, no such impediment remained.Footnote 250 Although the Leader of the Opposition, Jeremy Corbyn, maintained that Resolution 2249 did not give ‘unambiguous authorisation’Footnote 251 as it was not adopted under Chapter VII, other opponents of action (on non-legal grounds) adopted the more sophisticated legal argument that although ‘it does not authorise force … it implies a reference to self-defence, which would be a lawful basis for action’.Footnote 252 Such interventions highlight the significance of Resolution 2249 to the claim that the action's legality rests on self-defence grounds. The Government's interpretation of the Resolution means that it does not have to establish that it is responding to an armed attack as it argues the UNSC accepts there is a threat to international peace and security and this is interwoven into any subsequent Article 51 claim.
In setting out the Government's motion, Prime Minster David Cameron was at pains to emphasize his responsiveness to MPs' concerns,Footnote 253 but some of the established shortcomings of Commons authorization once again came to the fore. On the military grounds for intervention, despite Prime Minster David Cameron's insistence that the ISIS ‘threat is very real’,Footnote 254 he provided little detail of the links between ISIS and the recent terror plots against the UK which he recounted. Even if many parliamentarians accepted the threat posed by ISIS as a given in light of its international terrorist attacks, and the support for the Prime Minister's analysis in Resolution 2249, MPs struggled to get much detail regarding the ground forces that the Government regarded as vital to the success of operations against ISIS. Prime Minster David Cameron's assertion that as many as 70,000 fighters could be available to seize territory currently held by ISIS was widely disputed as ‘absurd’,Footnote 255 but the Government continued to deflect criticism on the basis that this constituted the independent analysis of the Joint Intelligence Committee.Footnote 256 The Prime Minister's insistence in the Commons' Chamber that a vote either way on this issue was ‘honourable’Footnote 257 could not disguise the efforts by Government whips to bring potential Conservative dissenters into line. The allegation that he had warned Conservative backbenchers off siding with ‘a bunch of terrorist sympathisers’Footnote 258 indicates the degree to which jingoism and party loyalty can be used by the executive to garner support for military action. No summary of the Attorney General Jeremy Wright's legal advice was published in advance of the Commons vote, even though he informed the Commons that ‘the legal basis for action … is not dependent on the presence of a Security Council resolution’.Footnote 259 For all of the discussion of Resolution 2249 in the debate, the motion for air strikes merely welcomed the Resolution and drew instead upon the UN Charter as providing a ‘clear legal basis to defend the UK and our allies’.Footnote 260 Few MPs displayed an appreciation for this distinction, with many instead wrapping themselves in the language of Resolution 2249. Some explicitly referenced the House of Commons' Library Briefing PaperFootnote 261 that had explained the relationship between the UNSC Resolution and Article 51.Footnote 262 Useful as this resource undoubtedly proved, as is the case with MPs the few legally-trained Library staff had no access to the Government's detailed legal advice and so could not analyse its reasoning.Footnote 263
Parliament's response demonstrates a surprising waypoint in the past two decades of its developing role in authorizing the use of force. MPs showed themselves to be resistant to attempts to put Parliament in the place of international legal processes on the use of force. The UNSC's intervention changed the dynamic at Westminster, supplying ‘the reason for urgency and the reason why we have to take action’.Footnote 264 The UK Government's desire to contribute to collective security by stepping up operations against ISIS looked unlikely, of itself, to sway MPs towards accepting such action. It was not until Resolution 2249 recognized the threat ISIS posed to international peace and security that the UK Government claimed that self-defence provided a legal basis for action. But the UK Government's refusal to publish even a summary of legal advice, and the evident shortcomings in the information Parliament received on the security situation in Syria point to the risks remaining in Parliament's new role. The November 2015 debate evidences many MPs' heightened awareness of international law's precepts after a decade of UK interventions in the Middle East and the Maghreb. The consequences of those interventions have also led to heightened scrutiny of the UK Government's security claims. When the afterglow of these actions fades, the systemic weaknesses in parliamentary authorization may return to limit this constraint on the war prerogative. Moreover, future UK Government ministers looking back at the precedent of the 2015 debate will likely emphasize that the action was justified on the basis of self-defence. Once again, the UK Government has protected its capacity for future uses of force without UNSC authorization.
VI. CONCLUSION
At a time when the UNSC faces sustained criticism as a result of its perceived failure to address threats to international peace and security successive UK Governments have cultivated approaches to the use of force which further marginalize its role. First, they have set out to justify military actions on an assortment of grounds, including legally dubious applications of doctrines such as humanitarian intervention and pre-emptive self-defence. These doctrines, invoked on the basis of precedents which are either not applicable to the claims made or which are highly disputed, seek to loosen the Charter's strictures upon the use of force. Second, having used these grounds to shift the focus of use of force decision-making away from the UNSC, the UK Government has accepted a new constitutional convention enhancing Parliament's role in this process. Although this shift in practice might appear to enhance domestic oversight of the war prerogative there is reason to suspect that ministers were not unduly troubled by the prospect of ‘democratic oversight’. Underpinning Commons' authorization on the UK Government's stated grounds is the seductive idea that a domestic legislature, through its deliberative character and democratic nature, can provide a better basis for checking use of force proposals than the UN's supposedly outmoded institutional arrangements.
Prime Minister David Cameron's administrations have sought to substitute the flexibility of an appeal to MPs for the rigidity of UNSC processes. As we have shown, for all that Cameron's ministers have made loud play of their respect for Parliament to draw legitimacy from its consultative votes, the Young Convention has not enhanced the tools at Parliament's disposal for assessing whether a use of force is legal and in the UK's national interest. Terse accounts of the legal grounds have often had to be extracted from the Prime Minister's statements proposing an intervention. Without a dedicated legal service, MPs can struggle to make sense of the myriad of legal justifications for military action advanced since the 2011 Libya intervention. Moreover, for security reasons, the UK Government has refused to share with Parliament the factual information necessary for MPs to assess whether grounds such as self-defence can indeed be invoked. Parliament has, nonetheless, been far from toothless. The Commons defeat on intervention against the Assad regime in Syria in 2013 was a severe reversal for UK foreign policy. A secure Commons' majority in favour of action against ISIS in Syria in 2015 only coalesced following the passing of UNSC Resolution 2249. Notwithstanding such setbacks, however, the Government's calculation remains in certain circumstances it will be more likely to succeed in the Commons than in the UNSC.
We do not claim that domestic assemblies ought not to be involved in use of force decisions, and indeed welcome meaningful additional scrutiny of proposed military action. But a domestic assembly's vote can have no significance in international law; it were to, other States would increasingly draw upon the authority of their own domestic assemblies in use-of-force decisions, even when the character of such assemblies are neither truly deliberative nor democratically elected. Also problematically, States subject to the proposed use of force, which have a voice within international institutions, are excluded from domestic decision-making processes. Democratic domestic assemblies should therefore be wary of becoming the predominant governance point for authorizing military force, on the principled basis that doing so would undermine UN institutions and on the pragmatic basis that legislators are ill-equipped to assess whether a use of force is legitimate under the tests currently in circulation. Relying upon domestic assemblies to provide the sole necessary authorization point for certain uses of force might appear to offer a means to unblock international institutional processes—but this course turns away from international constraints upon the use of force and opens the door to new forms of unilateralism.
