I. INTRODUCTION
Following the deaths and atrocities of World War II, the use of military force by states and the conduct of states in war became subject to extensive legal restrictions in the United Nations Charter of 1945 and the Geneva Conventions of 1949. Despite these restrictions, however, the use of force has continued, and millions of people have died and been mistreated in armed conflict. This potential “gap” between formal law and actual practice can lead to pessimistic conclusions about the broader irrelevance of international law in world politics, particularly in war, when the normative requirements of such law may conflict with the material interests of states. A realist observer, for instance, might argue that, because there is no true supranational authority able to protect states or control their conduct during hostilities, states, especially powerful ones, are not seriously constrained by the international law on the use of force (jus ad bellum) or the international law of armed conflict (jus in bello) when they use force, and will indeed violate law if it conflicts with their political and military interests in such matters.Footnote 1 Similarly, some rational choice views might suggest that the impact of international law will be limited or epiphenomenal to the primacy of states’ material interests in contentious “zero sum” issues like war.Footnote 2
In response to such pessimism, a small but growing body of International Law [IL] and International Relations [IR] research has sought to challenge its theoretical and empirical accuracy, and demonstrate that international law can impact even “high politics” areas such as security and armed conflict.Footnote 3 However, as I elaborate below, this exciting field of research has tended to focus overwhelmingly on America's conduct and recent wars. Moreover, although legal scholars interested in such political topics often assume that the binding, obligatory nature of international law—like all law—helps it play a distinct and significant role in international politics, there is limited empirical work that assesses this fundamental conceptual premise.
To help address these gaps in the literature and advance the interdisciplinary debate, the following study examines the impact and interpretation of international law in the use of force by an important but comparatively understudied country—the UK—during one of the most significant, destructive, and overlooked conflicts since 1945—the Korean War of 1950–53.Footnote 4 It addresses two main questions. First, how, if at all, did international law influence Britain's conduct regarding the use of force in this war, and the nature and scope of such force? Second, if international law played a role in such conduct, to what extent did policy-makers understand it as a distinct and binding set of legal rules, and to what degree did the legal status of these rules affect their decision-making? To address these questions, key aspects of Britain's participation in the Korean War are analyzed. These key aspects touch upon Britain's policy and conduct regarding: (a) whether and how to be involved in the war; (b) the major international legal issues related to the crisis; and (c) the treatment of enemy prisoners. I draw on “interactional” IL theory and constructivist IR theory—described more below—and employ a method of historical reconstructionFootnote 5 and process tracing.Footnote 6 I centre my analysis on the discourse and practice of Britain's main political and military leaders, as well as the views and actions of key officials. I examine relevant government archive documents, public statements, private diaries, memoirs, and secondary sources to reconstruct and trace: (a) the policy options that were considered about the key aspects of Britain's involvement noted above; (b) whether and how the thinking and decisions of leaders and officials were affected by international law; and (c) the extent to which leaders and officials saw this law as distinct and binding.
With the above in mind, I advance a two-pronged argument. First, contrary to what realist and rational choice views might predict, international law helped define and shape Britain's possible course of action in the Korean War, and the justifications that could be made for its behaviour. More specifically, Britain's involvement illustrates the four roles that I theorize law can play in the use of force: (1) it helps constitute the identities of actors; (2) it helps regulate their political and military practice; (3) it permits and legitimates certain behaviour that otherwise might not be permitted; and (4) it helps structure the process by which agents seek to develop and promote new legal rules and legitimate conduct. However, I also contend that, contrary to what many IL scholars might predict, the discourse and actions of UK leaders and officials in the Korean War offer mixed support for the hypothesis that, when states use force, policy-makers understand international law as a distinct and binding set of legal rules, and the legal status of these rules impacts their decision-making.
Such a study seeks to make a valuable and original contribution to academic knowledge in the IL and IR literature, and to broader policy debates in these fields. For instance, existing IR research that examines the role of non-material factors in world politics and the use of force has often focused more on moral norms and less on the specific phenomenon of international law.Footnote 7 Further, the limited work that does analyse law's role in world affairs has often avoided security issues,Footnote 8 or focused on American security practicesFootnote 9 and recent conflicts.Footnote 10 To this extent, examining the impact of international law in the Korean War helps address a historical gap in the literature. And analyzing Britain—a significant but comparatively understudied international actor whose public support for law often conflicts with its security concerns and US policy wishes—broadens the empirical scope of this work. In turn, the above focus will help develop and assess existing understandings of the role, and limits, of international law in world politics and armed conflict, and help make such understandings more comprehensive and historically informed.
For example, although the conflict in Korea was one of the most destructive and important wars of the twentieth century, with up to four million Koreans dying, it nonetheless often remains a “forgotten” war among scholars and the public alike.Footnote 11 As will be seen below, the crisis ultimately pitted the collective security promise of the UN Charter against the material realities of the nascent Cold War. In this confrontation between law and power, America's allies sought to constrain the situation from devolving into a third world war. As one such ally, Britain's extensive involvement in the crisis continues to be empirically puzzling and theoretically illuminating seventy years later. Unlike other colonial conflicts of the time, such as those in Kenya, Malaysia, and Egypt,Footnote 12 the UK thought Korea was not strategically important, and its Labour government was focused on socioeconomic issues following World War II. Most importantly, Britain's alliance with the US and its fear of the USSR do not adequately explain why and how it decided to use force in Korea, and to support UN activity regarding the war. Britain's participation, I will suggest, cannot be fully understood without reference to normative considerations such as the obligations and rights that leaders believed the country had under international law.
Finally, existing research on the impact of international law in international affairs has largely avoided the theoretically important but methodologically difficult question of how such law is actually understood by leaders and officials. To this extent, then, this paper aims to help break new conceptual and empirical ground in the IR and IL literature, and advance related theoretical discussions in these fields. Constructivist IR perspectives, for example, often cite international law and draw on legal philosophy.Footnote 13 But they have inadequately explained what distinguishes international law from other normative phenomena in world politics, or how legal and non-legal norms differ.Footnote 14 The dominant assumption among interdisciplinary scholars interested in such questions, including the present author, is that the binding, obligatory nature of international law, like all law, helps it play a distinct role in world affairs.Footnote 15 But there is limited empirical work that qualitatively examines this fundamental conceptual premise, and the following study seeks to help respond to this gap in the literature.
The paper is organized as follows. I first briefly outline the theoretical framework that guides my examination of Britain's participation in the Korean War. Next, I provide a short background to the conflict and why Britain got involved. I then consider the key aspects of UK policy and practice noted earlier, and analyze whether and how these aspects reflect the four roles that I posit international law can play in the use of force. Next, I examine whether policy-makers understood such law as a distinct and binding set of legal rules, and whether the legal status of these rules impacted their decisions. This is done by assessing Britain's interpretation of the UN Security Council resolutions on the crisis, and a key provision in the Third Geneva Convention on Prisoners of War [POWs].Footnote 16 I conclude by analyzing what my findings mean for existing theory in the fields of IL and IR, and positing suggestions for future research.
II. THEORETICAL FRAMEWORK
Drawing on the analytical insights of constructivist IR theory, and interactional IL theory as argued by Jutta Brunnée and Stephen Toope,Footnote 17 I posit that international law can play four main roles in the use of force: (1) it helps constitute the identities of actors, whether these are states (i.e. at the macro-level of analysis), or individual leaders (i.e. at the micro-level of analysis); (2) it helps regulate the political and military practice of actors, where regulate means to govern or control by law; (3) it permits and legitimates certain behaviour that otherwise might not be allowed; and (4) it helps structure the process by which agents seek to develop and promote new legal rules and legitimate conduct for states and other international actors. I elaborate on each role briefly below.
First, international law helps constitute the identities of actors. As readers familiar with IR theory will recall, constructivists often emphasize the “productive” power of normative structures such as international law, and argue that normative structures can help shape actors’ identities and interests, and act as a site for “communicative” struggles over legitimate identity and rightful behaviour.Footnote 18 Thus, insofar as the jus ad bellum and jus in bello are normative structures, we would expect them to have productive influence on the actors bound by their rules, and to help shape the identities and interests of these actors. For instance, regarding the jus in bello, Chris Reus-Smit notes that, when states negotiated the laws of war, they were not just enshrining a set of rules, they were “proclaiming a particular conception of legitimate statehood and rightful state action”.Footnote 19 Thus, regarding this study, because Britain helped negotiate the 1949 Geneva Conventions,Footnote 20 we would expect it to think that, as well as codifying a body of legal rules, it was also proclaiming a particular idea of legitimate statehood and appropriate conduct.
Second, international law helps regulate the political and military practice of actors leading up to and during the use of force. By regulate, I mean that international law helps govern or control such practice by law—i.e. by a felt sense of legal obligation—and less by material self-interest, as rationalists might suggest, or by coercion, as realists might argue. As both constructivists and neoliberal institutionalists note, normative structures can constrain state action,Footnote 21 including the conduct of strong states.Footnote 22 Consistent with this view, even constructivists who stress the constitutive nature of most international legal norms acknowledge that jus ad bellum and jus in bello norms regulate the use of force.Footnote 23 Of the two main definitions for “regulate”—i.e. to govern or control by law, or subject to legal restrictions—the former is more active and thus relevant to this study.Footnote 24 By employing this active definition, and recalling the interdisciplinary assumption noted earlier about law's binding nature, I am theorizing that Britain's participation in the Korean War was governed or controlled in part by jus ad bellum and jus in bello rules, and it is a felt sense of legal obligation among at least some policy-makers that did this governing or controlling.
Third, international law permits and legitimates certain actions that otherwise might not be allowed. As Nina Tannenwald argues, in addition to constitutive and regulative influence, norms also have permissive effect. “This refers”, Tannenwald notes, “to the way norms … by serving as focal points, selectively divert our normative gaze.”Footnote 25 For instance, she argues that the nuclear taboo, the norm she studies, labels some weapons as “weapons of mass destruction” and others as “conventional” and thus legitimate. Similarly, because much of what the jus ad bellum and jus in bello do is prohibit certain conduct (such as the unilateral use of non-defensive force, or the inhumane treatment of prisoners), it can be easy to forget that these branches of international law also permit and enable particular conduct and justifications (such as the use of force in self-defence or when authorized by the Security Council, and the intentional killing of combatants in war or the unintentional killing of civilians if this is militarily necessary and proportional). However, by permitting and enabling these actions and justifications, remember that the jus ad bellum and jus in bello are also helping to legitimate the use of armed force and the organized killing and suffering of human beings in certain circumstances.Footnote 26
Finally, international law helps structure the development of new legal rules and legitimate conduct. Drawing on two constructivist propositions—i.e. that normative structures shape the behaviour of actors, but structures only exist because of social agents—Brunnée and Toope posit that shared understandings are collectively held background knowledge, norms, or practices which are generated and maintained through social interaction.Footnote 27 Moreover, while agents generate and promote particular shared understandings, once in existence such collective views become normative and ideational structures that can create new categories of action and act as a site for communicative struggles over legitimate identity and behaviour.Footnote 28 Thus, insofar as the jus ad bellum and jus in bello represent particular shared understandings among a “community of legal practice” (to use Brunnée and Toope's term), we would expect these branches of international law to help structure the process by which agents within this community seek to generate and promote new legal norms and legitimate behaviour. For example, when the collective security provisions of the UN Charter and the mandate of the Security Council were negotiated, the nature and scope of these negotiations were shaped in part by shared understandings of pre-existing treaties such as the 1919 Covenant of the League of Nations and the Kellogg-Briand Pact of 1928.Footnote 29
In addition to studying the impact of international law, this paper also analyses whether leaders view this law as a distinct and binding set of legal rules, and whether the legal status of these rules affects their decision-making. In doing so, I seek to respond to Andrew Hurrell's suggestion that, if we want to understand whether and how states feel bound by international law, then we need to look in far more detail at how this sense of obligation plays out within the policy-making process and among the individual decision-makers who are capable of feeling a sense of obligation.Footnote 30 As evidence of whether British leaders and officials during the Korean War felt bound by international law, I analyze the historical sources noted earlier for “law talk”Footnote 31 and employ the concept of legal obligation. If individuals felt bound by law, then we should see them: (a) recognize that the use of force and the treatment of prisoners were in part legal issues, in that they were governed by a pre-existing set of international legal rules; (b) discuss the extent to which they were legally obligated to consider these rules when deciding whether and how to use force in Korea, and what policy to adopt for captured prisoners; and (c) acknowledge that, due to their legal nature, these rules should apply reciprocally and equally.Footnote 32
Further, if UK leaders and officials felt bound by law, they should recognize that breaching relevant international legal rules could lead to civil litigation or criminal prosecution at the domestic or international level,Footnote 33 and would require legal justification at the national and international level.Footnote 34 They should also express concern that decisions regarding the use of force should follow, not precede, any legally significant events related to such force.Footnote 35
Cognisant of the theoretical framework outlined above, I now turn to the empirical component of this paper.
III. BRIEF BACKGROUND TO THE KOREAN WAR
Following World War II, Korea was occupied by the US south of the 38th parallel, and by the USSR north of this line. After bilateral independence talks proved fruitless, America asked the UN to get involved. A UN-supervised election was held in South Korea in May 1948,Footnote 36 and the General Assembly recognized the Republic of Korea [ROK]. A separate election was held in the north, and the Democratic People's Republic of Korea [DPRK] was recognized by the USSR and its allies.
On 25 June 1950, DPRK forces crossed the 38th parallel to unify the peninsula by force. ROK forces virtually collapsed and retreated south. In response, US President Harry Truman announced on 27 June that America would provide military support to South Korea, and deploy the Seventh Fleet to protect Formosa (Taiwan) from potential Chinese Communist attack.Footnote 37 Truman also sought UN support for an international military operation to restore peace in the area. To this end, the US secured three key resolutions from the Security Council. The first, entitled Complaint of Aggression upon the Republic of Korea, was passed on 25 June. It determined that North Korea's attack constituted “a breach of the peace”, and called for the cessation of hostilities and withdrawal of DPRK forces to the 38th parallel.Footnote 38 The second resolution of 27 June noted that North Korea had not withdrawn, and recommended that UN members furnish such assistance “as may be necessary” to repel the attack and restore peace in the area.Footnote 39 The third resolution of 7 July recommended that UN members providing help do so under a unified US command.Footnote 40 America was able to pass these resolutions because the USSR was boycotting the Security Council at the time for refusing to recognize Communist China.
Truman named US General Douglas MacArthur as UN commander. American forces arrived in Korea in July, and thirty-nine other countries, including Britain, contributed to the effort. Following initial military setbacks, UN forces recaptured South Korea in September.Footnote 41 By late October, they had reached China's border. This occurred under a “rollback” doctrine, whereby US leaders decided that, rather than restoring the status quo, UN forces would cross the 38th parallel and unify Korea by force. In response, China intervened. Over the coming months, hundreds of thousands of Chinese soldiers (described as “volunteers” by China's leaders) entered Korea and helped push back the UN force. Seoul was captured in January 1951, and retaken by UN troops in March. Truman dismissed MacArthur in April, because he had publicly criticized the President and obstructed peace negotiations. Opposing forces became divided along the 38th parallel, and engaged in trench fighting for two more years. Difficult peace talks continued during this time, due to disagreement over the future demarcation line, and the controversial issue of whether communist prisoners who did not want to return home should nonetheless be repatriated. An armistice was finally signed on 27 July 1953. More than sixty years later, the war continues today through a “cold peace”, with thousands of US soldiers stationed in South Korea, and over a million North and South Korean troops confronting each other along the demilitarized zone.Footnote 42
IV. WHY BRITAIN PARTICIPATED IN THE KOREAN WAR
In the language of political scientists, the “puzzle” to be explained is why Britain participated so extensively in the Korean War when a number of factors suggested it would not do so. Many UK officials initially believed the crisis should be solved by other states,Footnote 43 and throughout the war political and military leaders thought Korea was not strategically important.Footnote 44 Further, Britain was encumbered with other imperial concerns at the time, such as an anti-colonial uprising in Malaysia, and the Labour government of Prime Minister Clement Attlee was focused on improving the socioeconomic conditions of a country still impoverished and in debt from World War II. Despite these considerations, Britain ultimately participated, at great financial and human cost,Footnote 45 in a divisive and bloody civil war located on the other side of the world. Scholars generally cite three reasons: (1) the perceived security threat of the USSR and the assumption that it was ultimately responsible for North Korea's attack; (2) a belief that strengthening Britain's relationship with America was the best way to address the Soviet threat, and that fighting in Korea would further this goal; and (3) the view that, because of Britain's prior experience with Germany, aggression must not be appeased.Footnote 46
These reasons are indeed crucial to understanding Britain's involvement in the Korean War. However, some leading authorities prioritize them to such a degree that they portray Britain's response as “inevitable”.Footnote 47 The evidence analyzed by this study challenges this deterministic view, and suggests that Britain's decisions to send military forces were not inevitable, particularly its decision to provide ground troops. More generally, to understand the UK's response to the crisis, one must recall that, in addition to addressing the Soviet threat and improving the American alliance, four other objectives were important to Britain at the time: (1) maintaining its position as a world power; (2) maintaining the Commonwealth structure; (3) consolidating “Western” democracy; and (4) ensuring that the Middle East and Asia were stable and friendly.Footnote 48 Indeed, because a government paper in April 1950 listed the first two goals ahead of strengthening the US alliance and resisting Soviet Communism, some scholars argue that Britain was more concerned with prestige and status than with security.Footnote 49 To this extent, non-material considerations and Britain's self-identity are also relevant to understanding its response to the Korean crisis.
Further, Britain's pursuit of the four other goals above during the conflict sometimes led it to adopt policies that clearly ran against the perceived wishes of the US.Footnote 50 For instance, Britain's legal recognition of Mao's Communist China, its trade interest in that country, and London's financial interest in Hong Kong, often put UK leaders at odds with their American counterparts. In addition, there is evidence that public opinion—both in Britain and internationally—as well as emerging understandings of the relevant tenets of international law and Britain's relationship to that law, influenced the discourse and actions of the Attlee and Churchill governments during the conflict. Finally, and most importantly for this study, there is evidence that a perception of obligation under the UN Charter and Geneva Conventions affected the thinking and decisions of these governments regarding the war, and the justifications that could be advanced for the UK's actions.
V. THE FOUR ROLES OF INTERNATIONAL LAW
Britain's participation in the Korean War offers evidence in support of the argument that, when states use force, international law helps define and shape their possible course of action, and the justifications that can be made for their behaviour. More specifically, the UK's involvement illustrates the four roles of international law that were posited earlier.
A. International Law Helped Constitute the Identities of Key UK Leaders
The fact that Britain decided to (a) support the Security Council resolutions on the Korean crisis, and (b) contribute significant naval, air, and ground forces to the UN mission there even though political and military leaders thought the country was not strategically important, suggests that international law can help constitute a state's identity and be used to reorient its political and military objectives. As will be seen below, Prime Minister Attlee felt a strong sense of obligation to the UN and the conflict in Korea, and there is evidence that this perception of obligation was partly comprised of and affected by Britain's formal membership in the UN, as well as Attlee's belief in the international rule of law. While other UK leaders, such as the Defence Chiefs, did not feel the same responsibility regarding the UN and the Korean crisis, Attlee sought to reorient their thinking and explain Britain's actions by reaffirming the importance of responding to aggression; making the new world organization effective; and upholding the rule of law in international affairs.
For example, Attlee instructed Britain's UN delegation to vote for the first Security Council resolution on the crisis, and this was endorsed by the Cabinet on 27 June 1950.Footnote 51 At this meeting, the Cabinet Secretary remarked that “Korea is rather a distant obligation, Prime Minister”. To this Attlee replied, “Distant—yes, but nonetheless an obligation”.Footnote 52 Accordingly, the government also supported the Council's second resolution, provided its scope was limited to Korea, as well as the third resolution.Footnote 53
While Britain's support for the Council resolutions was relatively forthcoming, its decisions to send naval, air, and ground forces to Korea were less so. In response to the second resolution, the Defence Chiefs and Cabinet agreed that Britain's naval forces in JapanFootnote 54 should be placed under US command “to operate on behalf of the Security Council in support of South Korea”.Footnote 55 However, the Chiefs stressed, no land or air forces should be sent, as this would divert resources from more important areas like Europe and Hong Kong. Similarly, acting Foreign Secretary Kenneth Younger and his advisers thought that sending troops would seriously jeopardize Britain's existing defence commitments in the Far East.Footnote 56
As the UN's military position in Korea deteriorated in July, the US asked the UN Secretary General to appeal for further contributions, and pressured Britain to send troops.Footnote 57 The Cabinet thus faced a policy dilemma, in that the government's purported commitment to the UN, described below, its need to show its continued relevance to America, and its ongoing belief in Britain's world role, were pitted against the realities of an already stretched military commitment, the implications of increased defence spending on domestic socioeconomic programmes, and the warning of military leaders.Footnote 58 In response to this dilemma, Attlee convinced his Cabinet on 25 July to send the 29th Infantry Brigade from Britain.Footnote 59 A month later, in response to renewed American requests and advice that the threat to Hong Kong had decreased, Attlee and Foreign Secretary Ernest Bevin also agreed to send the 27th Infantry Brigade from that island.Footnote 60
Britain supported the Security Council resolutions on Korea and contributed to the UN force there in part because the government thought a clear act of aggression had occurred. As Deputy Prime Minister Herbert Morrison emphasized at a Labour party rally in July, free democracies needed to act in Korea to demonstrate that “aggression does not pay”.Footnote 61 Similarly, Prime Minister Attlee stressed in a public broadcast that North Korea's attack was denounced as aggression by the UN, and if they get away with it, “aggressors all over the world will be encouraged”.Footnote 62
There is evidence that Attlee's support for the UN during the Korean War, and his perception of obligation, noted earlier, regarding the conflict, were sincere and shaped by Britain's formal membership in the UN and by Attlee's belief in the international rule of law. However, this evidence also suggests that Attlee prioritized these factors more than most other British leaders. For example, prior to World War II, Attlee had been committed to the principles underpinning the League of Nations.Footnote 63 Emphasizing this commitment to Parliament in 1935, he stated that Britain can only truly defend itself “by moving forward to a new world—a world of law, the abolition of national armaments with a world force” (emphasis added).Footnote 64 After the war, the Labour government actively contributed to the establishment of the UN, and Attlee transferred his support for the League to the new world organization.Footnote 65 For instance, during the Potsdam Conference of July 1945, Attlee noted in diplomatic correspondence that:
The concept of the special interest of Great Britain in the strategic areas and the acceptance of responsibility for them involves us in a continuing heavy burden of defence expenditure … If we really believe and intend to operate a world organisation for peace we ought, I think, to get away from old conceptions. In my view the only realistic policy is that of placing all these strategic areas under international control, not the control of one or two powers, but of the United Nations.Footnote 66
Attlee's outlook was criticized by some members of the UK Foreign Office [FO]. The head of reconstruction at the FO, for instance, questioned Attlee's concern about “power politics”, and argued that, until the countries of the world are prepared to renounce their sovereignty and create a World State, “international politics can only be an expression of power”.Footnote 67
Nonetheless, Attlee continued to prioritize the UN, and its role in Britain's foreign policy. In September 1945, he argued in a memorandum to Cabinet and military leaders that:
The British Empire can only be defended by its membership of the United Nations Organisation. If we do not accept this, we had better say so. If we do accept this we should seek to make it effective and not at the same time act on outworn conceptions. If the new organisation is a reality, it does not matter who holds … Somalia or controls the Suez Canal.Footnote 68
Military leaders tended to disagree with this view.Footnote 69 The Chief of the General Staff, for instance, wrote in his diary that they were “shaken by Attlee's new Cabinet paper in which apparently the security of the Middle East must rest in the power of the United Nations!!”.Footnote 70
Again, Attlee continued to support the UN. He also stressed the importance of the rule of law in world affairs. Speaking in January 1946 at the opening session of the General Assembly in London, he stated that the UN:
must become the overriding factor in foreign policy … [T]he world has passed into a new epoch. In just such a spirit in times past in these islands great nobles … used to practise private war in disregard of the authority of the central government. The time came when private armies were abolished, when the rule of law was established throughout … this island. What has been done in Britain … has now to be effected throughout the whole world.Footnote 71
Picking up on this theme at a Labour Party meeting in November 1946, Attlee re-emphasized the centrality of the UN to the party's international outlook. “The Government”, he told critics who worried that Britain was moving too close to the US in the emerging Cold War, “does not believe in [ideological blocs] … We stand for the United Nations.”Footnote 72
In sum, the above indicates that Attlee's support for the UN during the Korean crisis, and his perception of obligation regarding the conflict, were sincere and shaped in part by Britain's formal membership in the organization and by Attlee's belief in the international rule of law. While other UK leaders may not have felt the same responsibility regarding the UN and the crisis, Attlee sought to reorient their thinking and explain Britain's actions by emphasizing the importance of responding to aggression and making the new world body effective. In this context, the fact that Britain ultimately supported the Security Council resolutions on Korea, and contributed significant military forces there even though the country was not seen as strategically important, suggests that international law can help constitute a state's identity and be used to reorient its political and military objectives.
B. International Law Helped Regulate Britain's Conduct
Alongside its constitutive effect, international law had a regulative impact in the Korean War. Two examples of this are Britain's non-participation in the US blockade of Taiwan, and its use of the Security Council resolutions to help constrain America's response to the crisis.
First, recall that, when the Attlee government supported the Council's second resolution, it did so provided the instrument's scope was limited to Korea. Accordingly, recall further that when the Cabinet and Defence Chiefs sent UK naval forces to the UN mission, these forces were to operate on behalf of the Security Council to support South Korea. In the debate behind this decision, First Sea Lord Fraser said “It was important that any operations … undertaken by British Naval Forces should be in support of South Korea and not in protection of [Taiwan] or in any way against the Communist Government in China”.Footnote 73 The Cabinet Defence Committee, which was chaired by Attlee, agreed. As such, during the next three years of the Korean War, Britain's naval assets did not participate in the Taiwan blockade, and were “strictly limited to resisting aggression in Korea”.Footnote 74
In addition to its understanding of the second Council resolution, there is further evidence that international legal considerations helped shape Britain's non-involvement in the Taiwan blockade. It was agreed in a meeting on 30 June 1950 between acting Foreign Secretary Younger and some Cabinet Ministers that, in any public statement, Britain would “welcome” America's action around Taiwan because the island was a “ward of the allied powers and it was in our interest that orderly government should be maintained there until a peace treaty was signed”.Footnote 75 However, leaders would also emphasize that British “forces were not involved in the [Taiwan] action and while we approve of that action we did not participate in it because of the special legal position we were in” (emphasis added).Footnote 76
Younger and the other ministers did not specify what they meant by the “special legal position” that Britain was in regarding Taiwan. However, they were likely referring to the fact that the Attlee government: (a) had recognized Mao's Communist regime as the de jure government of China on 6 January 1950 while the US had not;Footnote 77 (b) would continue this recognition during the Korean War; and (c) thought that, following an appropriate treaty, China should regain authority over Taiwan. To this extent, these leaders likely thought that the international legal position Britain had previously articulated prevented it from participating in any coercive military action that—while “welcome” and consistent with its interest in order—nonetheless conflicted with this legal position and risked a broader war with China.
Note that the government refused to allow UK forces to participate in the Taiwan blockade even though some British officials thought such participation might prove necessary if China attacked the disputed island. In a draft paper dated 24 July 1950, R.H. Scott of the Foreign Office gave a joint FO-Commonwealth Relations Office view “on behalf of implicit British involvement in [Taiwan] in the event of a Communist attack”.Footnote 78 In response, Foreign Secretary Bevin strongly dissented, and argued that “any of [Scott's] recommendations means a general war”.Footnote 79 This empirical observation is relevant for two reasons. First, it suggests that, contrary to what a deterministic account might suggest, Britain's policy on Korea was neither inevitable nor dictated solely by the US. Second, this observation resonates with other studies that have found that international law helped regulate a state's use of force.Footnote 80 Consistent with this investigation's findings, these studies assume that one way to show that law helped govern or control a state's use of force is to find evidence that (a) some leaders or advisers considered implementing military responses that were broader or more severe than the force that was actually employed, and (b) these broader or more severe responses were avoided in part because other leaders thought this would be more consistent with international law. Finding such evidence regarding Britain's participation in the Korean conflict therefore helps to suggest that international law influenced the UK in this war.
Another related example of law's regulative impact is Britain's use of the Security Council resolutions to help constrain America's response to the Korean crisis.Footnote 81 During negotiations on the second resolution, for instance, the US suggested that other Communist Asian “encroachments” be mentioned, and the invasion be attributed to “centrally directed Communist Imperialism”.Footnote 82 Drafts of Truman's announcement on 27 June, noted earlier, expressed similarly expansive and accusatory language. Concerned, Bevin told the Americans that the resolution should be confined “strictly” to Korea, and omit threats which had not yet been brought before the Council.Footnote 83 Similarly, Younger asked that Truman's speech be modified. In the end, the US agreed to both requests.Footnote 84
When negotiating the third resolution, Britain was again able to influence these talks and America's position, and its interpretation of the international legal considerations at issue played a role in this regard. An early US draft of the resolution noted the Council's initial “decision” to assist South Korea, and suggested that an enforcement committee be created.Footnote 85 In response, Younger told Britain's UN delegation that calling the initial action a “decision” was erroneous, and an enforcement committee was similarly inappropriate because enforcement means action under Article 42 of the UN Charter, “whereas we are all agreed” that action is being taken under a “recommendation” in Article 39 and this should be kept clear.Footnote 86 Reflecting this view, UK diplomats helped steer their American counterparts away from the idea of an enforcement committee, and towards a solution which emphasized the UN character of operations while also giving freedom for their conduct to General MacArthur.Footnote 87
To understand the legal relevance of the above events, recall that Article 39 provides that the Security Council shall determine any threats to the peace, and “make recommendations, or decide what measures shall be taken” under the non-forceful provisions of Article 41, or the forceful measures of Article 42, to restore peace.Footnote 88 The word “decide” matters because, under Article 25, UN members “agree to accept and carry out” Council decisions in accordance with the Charter. Because the second Council resolution recommended that UN members help South Korea, UK leaders thought that UN forces were acting under the first-half of Article 39 and that this should be kept clear in the third resolution. We will see the significance of this interpretation arise again later below.
Importantly, Britain also used its understanding of the Security Council resolutions and other related legal instruments to help constrain America's behaviour regarding Taiwan. Attlee's government worried that the Taiwan blockade could expand hostilities in the area and, as noted earlier, saw the Council resolutions as limited to Korea. Accordingly, Bevin warned his US counterpart on 8 July that America could not rely on wholehearted UK support for a policy based on denying to Mao's government territory that had been promised to China under the Cairo Declaration of December 1943 and the Potsdam Conference of July 1945.Footnote 89 As a short-term response, Bevin successfully pressed for Truman to tell Congress on 19 July 1950 that all questions affecting Taiwan would be settled peacefully as envisaged in the UN Charter.Footnote 90 Thus, after MacArthur nonetheless went on to visit Taiwan later that summer and to publicly stress its strategic importance, Truman made him withdraw his statement and approved a military directive limiting US action in defence of the disputed island.Footnote 91
In sum, Britain's non-participation in the Taiwan blockade, and its use of the Security Council resolutions to help constrain America's response to the crisis, offer evidence in support of the observation that, when states use force, international law helps regulate their political and military practice.
C. International Law Helped Permit and Legitimate Britain's Conduct
When Britain reacted to the Korean crisis, international law also helped permit and legitimate behaviour that otherwise might not have been allowed. As will be seen below, the UK intervened militarily in what was in many respects an ideologically divisive and extremely violent internal, civil war, and justified this publicly and privately with reference to the Security Council resolutions on the conflict, and the UN Charter's provisions on self-defence.
Due to the majority interpretation of the Council resolutions, the US and UK thought that they were allowed to intervene militarily in what was in many ways an ideologically divisive and tremendously destructive civil war. The question of how British leaders and officials understood the complex legal situation in Korea, and whether it was a traditional war or novel police action, will be elaborated later below. For now, note that, consistent with the above description, Britain's Attorney-General observed that the rules of war would likely apply in Korea because such rules “have been applied in civil wars” in the past.Footnote 92 UK military action in this conflict, we saw Prime Minister Attlee stress earlier in public, was justified because North Korea's attack was denounced as aggression by the Security Council, and Britain was acting pursuant to this body's resolutions. In addition to these statements, there is further evidence that international legal considerations were relevant to explaining Britain's use of force to the UK public, and to securing the support of the international community.
In response to concerns from the public and left-wing Labour Party members regarding the international legality of Britain's military reaction,Footnote 93 a sophisticated legal defence was developed and articulated by the Attlee government, and prolonged and careful legal analysis of the situation was ordered. One concern was that, although South Korea was recognized by the General Assembly in 1948, it was not yet a UN member. Article 51 of the Charter, however, states that nothing in that treaty “shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a member of the [UN]”. At a meeting on 4 July 1950, the Cabinet observed that, although South Korea was not a UN member, “the action taken on her behalf was clearly in accordance with the principle embedded in [Article 51]”.Footnote 94 As Attlee explained in Parliament the following day, the purpose of this provision was “not to create a new right but merely to make it clear that an inherent right vested in every State is not prejudiced”.Footnote 95
Cognisant of this argument, the Cabinet decided that, while Attlee “should not ignore the constitutional points which were being made, [he] should argue that the action … in South Korea was fully in accordance with the spirit of the … Charter and was in fact the first significant demonstration of the principle of collective security against aggression”.Footnote 96 Moreover, the Cabinet held, “it was the duty of peace-loving nations to make the machinery of the [UN] work effectively, despite legal quibbles, and not to allow it to be frustrated by the abstentions of a single member”.Footnote 97 To this end, such nations “were entitled to take advantage of procedures which, though they might appear to conflict with the strict letter of the Charter, had been accepted as reasonable by member States”. As Attlee stated the next day, he hoped that Parliament would not focus on these “legal subtleties”, and instead concentrate on the central reality: if the UN “is not to go the way of the League of Nations, the members must be prepared to act when the need arises. If the peoples wish to avoid another world war they must support their Governments in asserting the rule of law.”Footnote 98
In Attlee's arguments, note that he articulates a slight contradiction, namely that Parliament should not focus on the international legal nuances of America's and Britain's use of force in Korea, but governments and their constituents should be upholding the rule of law there. This suggests that the broad substantive aims of the collective security regime were likely relevant to Attlee's thinking on the Korean conflict, but he was less concerned about implementing this regime according to the “black letter” procedural details of the Charter's text. That said, the legal concerns that were raised about these details appear to have shaped the public justification that Attlee could give in Parliament regarding Britain's use of force.
Perhaps because the military response to North Korea's attack might, as noted above, “appear to conflict with the strict letter of the Charter”, further legal analysis of the situation was ordered in the autumn of 1950 and winter of 1951. The role of this analysis in Britain's effort to create new collective security law will be described in the next section. For now, note that, like the Cabinet Ministers, UK Attorney-General H.W. Shawcross and Lord Chancellor Viscount Jowitt also recognized how international law could help legitimate Britain's use of force. As Shawcross remarked to Jowitt on 4 September 1950:
[F]rom one point of view it does not much matter what the law is: we are committed to a certain course of action and we must pursue it without any unduly nice argument about the legal position. But for the purpose of rallying world opinion it is … important to show that the steps we take are firmly based on the rule of law and for our own domestic purposes … it is essential to know on what view of the law we take our stand. (emphasis added)Footnote 99
In these remarks, note that Shawcross believed that, from one perspective, Britain's response must be pursued without excessive legal debate. However, he also thought that, to secure international support, Britain should show that its actions are based firmly on the rule of law.
In sum, UK leaders and advisors justified Britain's military intervention in Korea using the Security Council resolutions on the crisis, and the relevant treaty and customary law on self-defence. This supports the idea that, when states use force, international law helps permit and legitimate certain behaviour that otherwise might not be permitted.
D. International Law Helped Structure the Development of New Rules and Legitimate Practice
Finally, Britain's reaction to the Korean crisis suggests that, when states use force, international law helps structure the process by which agents seek to develop and promote new legal rules and legitimate conduct for international actors. An important example of this phenomenon is the Security Council's novel response to North Korea's attack, and the efforts of UK leaders to justify and study this response, and to create new collective security law.
When the Security Council authorized UN members to restore peace in Korea, it did so in a manner not anticipated by the drafters of the UN Charter in 1945. At that time, it was expected that members would provide permanent military forces to the Council under Article 43 of the Charter.Footnote 100 By June 1950, however, no such forces had been granted. Thus, following North Korea's attack, the Council authorized an ad hoc response that saw UN members provide their own forces towards a collective cause. As Thomas Franck notes: “Far from being paralyzed by the failure to realize the potential of Article 43, the system, in actual practice … developed new ways to deploy force to secure peace and resist aggression.”Footnote 101 The USSR said this reaction was invalid.Footnote 102 This was due mainly to the absence of the Soviet representative at the Council meetings when the Korean resolutions were passed. In response to this concern, UK leaders argued that the Council's actions were a necessary reinterpretation of the Charter's text, and consistent with altered state practice on the issue.
As the Cabinet noted on 4 July, under Article 27 of the Charter, Security Council decisions on non-procedural matters required the affirmative votes of seven members, including the concurring votes of permanent members; and it was argued that the Council's second resolution was invalid because the Soviet representative was absent.Footnote 103 On the other hand, the Cabinet observed, the Council had previously taken decisions despite the abstention of a permanent member: “the Soviet Government had at least acquiesced in that procedure; and it was arguable that the written constitution of the Council was in process of modification by practice.”Footnote 104 Moreover, they reasoned, it was relevant to this argument that forty UN members had subsequently supported the resolution.
Attlee drew on this thinking the next day when he updated Parliament on Britain's response to the Korean conflict. As he argued: “If a member of the Security Council, and in particular a permanent member, chooses to refrain from exercising its right of voting, not by failing to vote when present, but by refraining from attending the meeting at all, that member must be regarded as having deliberately abstained from voting.”Footnote 105
In sum, the above suggests that, during the Korean War, British leaders sought to alter existing understandings of (a) Article 27 of the Charter and (b) Security Council voting procedures in order to help develop and promote a new legal rule—i.e. that refraining from attending a Council vote is equivalent to abstaining from that vote—and new legitimate practice for the organization. Further, leaders aimed to strengthen their efforts by citing the Council's continuing practice, and the supporting views of forty states.
As the crisis in Korea progressed, UK leaders also, as we will see below, ordered extensive and sophisticated legal analysis of the conflict. Further, they consulted with other Commonwealth states and the US about using the situation to create new collective security law. Finally, leaders believed that, depending on how the conflict ultimately came to be understood by Britain and the international community, the UK might need to pass new legislation to address the domestic legal effects of such situations.
Reflecting on whether the Korean conflict constituted a traditional war or novel police action, Attorney-General Shawcross advised the Cabinet on 14 September 1950 that, because the situation was so unprecedented, Britain would to some extent be “able to make new law about it and the position we take up must have significant political and legal consequences”.Footnote 106 Elaborating on this view with Lord Chancellor Jowitt earlier that month, Shawcross expressed ideas that resonated with Attlee's speech to the UN General Assembly in 1946:
We have in effect the law-making function of declaring what the law is, [and] it may be that the present is … a proper … opportunity of distinguishing between war as a private, and now illegal, contention between States … and collective action for restraining the aggressor and enforcing the law. Just as in the field of domestic law action which would, as between private citizens constitute an illegal assault may, when taken by the State, constitute a legal use of force, so we must elevate collective action on behalf of the [UN] to the dignity of a legal institution higher than war …Footnote 107
Perhaps because this argument was without clear precedent, Shawcross advised the Cabinet along more traditional lines. He and Jowitt agreed that “English laws apply to the present conflict as if it were a war in the ordinary sense”, and Jowitt further thought that “the conflict is a war in the ordinary sense, both under municipal law and internationally”.Footnote 108 This view, Shawcross noted, contrasted with the position of US President Truman and Canadian Prime Minister Louis St. Laurent, who had both declared that their countries were engaged in a UN police operation. In the light of these declarations, Shawcross recommended that Britain should decide what position to adopt, and arrange for high-level consultation and potential agreement with other Commonwealth countries and the US.
After discussing this legal advice, the Cabinet decided that the practical aspects of the international status of the Korean conflict would be further examined by the Departments concerned, and that relevant Ministers and officials would discuss the legal and practical issues involved with their American and Commonwealth counterparts.Footnote 109 Summarizing the results of these efforts, Foreign Minister Bevin noted on 11 December 1950 that the “strong political arguments” for avoiding saying that Britain is technically at war with North Korea were reinforced by China's intervention that autumn.Footnote 110 Moreover, he said, the balance of practical advantage lay in treating the situation as an international police operation.Footnote 111 Commenting on this summary at a Cabinet meeting on 2 January 1951, Shawcross noted that “further investigation of the domestic implications of … regard[ing] such conflicts as police operations might reveal the need for legislation empowering the King to declare [that] … the consequences of being at war should follow the undertaking of police operations under [UN] auspices”.Footnote 112 Accordingly, the Cabinet ordered further study of the issue, and asked for a report to be written on the required legislation.Footnote 113
In sum, the above supports the observation that, when countries use force, international law helps structure the process by which agents seek to develop and promote new legal rules and legitimate practice for states and other international actors. This was seen in the Security Council's novel response to North Korea's attack, and the efforts of UK leaders to justify and study this response, and to create new collective security law.
VI. HOW INTERNATIONAL LAW WAS UNDERSTOOD
The aspects of Britain's involvement in the Korean War above support this study's main argument about how international law can influence the use of force by states. By contrast, the discourse and behaviour of UK leaders during the conflict offer mixed support for the idea that, when states use force, policy-makers understand international law as a distinct and binding set of legal rules, and the legal status of these rules impacts their decision-making. As will be seen below, leaders and officials tended to interpret the Security Council resolutions on the Korean crisis more in political and moral, rather than distinctly legal, terms. Moreover, while a key rule in the Third Geneva Convention on Prisoners of War (POWs) was seen in binding terms, the perceived requirements of this rule conflicted with other political and moral considerations at the time, and these factors appear to have ultimately exerted a greater impact on the government than the law at issue.
A. Britain's Interpretation of the Security Council Resolutions on the Korean Crisis
As previously mentioned, the main substantive provisions of the UN Charter animating Britain's understanding of the Security Council resolutions on the Korean crisis were Articles 39, 41, and 42. Recall that, under Article 39, the Council “shall make recommendations, or decide what measures shall be taken in accordance with Articles 41 and 42” to restore peace. And under Article 25, UN members “agree to accept and carry out” Council decisions. During the vote for the second Council resolution on 27 June 1950, the Egyptian delegate refused to participate because of the Council's “previous laxities and delays” on several other aggressions, particularly the conflict in Palestine.Footnote 114 Gladwyn Jebb, Britain's UN delegate, expressed disappointment at Egypt's decision. However, Jebb conceded that because the resolution “was only a recommendation, Egypt was free to make this decision if she so chose”.Footnote 115
By noting that the resolution “was only a recommendation”, Jebb was implying that it was not a decision. Consistent with this view, Jebb received advice from the Foreign Office beforehand that, for legal and expediency reasons, the resolution should be viewed “as a recommendation under Article 39 and not action under Article 42”.Footnote 116 This position, recall, also reflected acting Foreign Secretary Younger's subsequent comments to Jebb that “we are all agreed” that we are acting under the first-half of Article 39.
This view—i.e. that the Security Council's resolutions on the Korean conflict stemmed from a recommendation and not a decision—would recur in the government's analysis of the crisis. It suggests that, had the Council responded to the conflict by “deciding” to authorize measures under Articles 41 or 42, UK leaders and advisers would likely have believed that this imposed legally binding obligations on UN members. However, because the Council had “recommended” action under Article 39, this constituted more a political or moral request that members were technically free to ignore. As Attorney-General Shawcross noted on 4 September 1950, the operations in Korea “are not the result of any direction by the United Nations”.Footnote 117 This was because, he observed, “The Security Council refrained from action under Articles 41 and 42, which would have given rise to obligations on the part of member Nations, and contented itself with making recommendations under Article 39”.Footnote 118
Again, this suggests that—consistent with Jebb's and Younger's position—Shawcross believed that had the Security Council responded with a “decision”, this would have imposed a binding obligation on UN members. However, because he thought the Council had only made a “recommendation”, one could infer that, like Jebb, Shawcross also thought the first-half of Article 39 does not give rise to obligations in the way that Articles 41 and 42 do. Further, because Britain ultimately argued that UN forces in Korea were acting on a recommendation under Article 39,Footnote 119 this suggests that Shawcross might have contended that Britain contributed to these forces less because it was legally obligated to do so and more because of the political and moral considerations at issue.
B. Britain's Interpretation of Article 118 of the Geneva Convention on POWs
The provisions of the UN Charter described above are part of the jus ad bellum. Again, this body of international law governs the use of force by states, while the jus in bello—the international law of armed conflict—governs the conduct of states in war. As will be seen below, there is evidence that some British leaders and officials viewed a key jus in bello rule regarding POWs in distinctly binding terms. However, the perceived requirements of this rule conflicted with other political and moral considerations at the time, and these factors appear to have ultimately exerted a greater impact on the government than the law at issue.
At the outbreak of the Korean War, the US and North Korea both said they would abide by the Geneva Conventions of 1949.Footnote 120 Like America, Britain was an original signatory to these treaties. Although it did not ratify them until 1957, we saw Attorney-General Shawcross observe earlier that the rules of war would likely apply in Korea because such rules have been applied in past civil wars, and the Geneva Conventions reflect this accepted practice.Footnote 121 Accordingly, he advised, Britain and the UN should perhaps declare that they are prepared “on the basis of reciprocity” to apply the accepted rules of warfare.Footnote 122
A rule that became highly relevant during the Korean conflict was Article 118 of the Third Geneva Convention on POWs. This provision requires that “Prisoners of war shall be released and repatriated without delay after the cessation of active hostilities”.Footnote 123 The language of the Article is clear because, following World War II, the USSR held on to many of its POWs as forced labour.Footnote 124 As such, in arguing for Article 118, the US and its allies aimed to shed light on Moscow's behaviour and prevent such non-repatriation from occurring in future wars.Footnote 125 However, the rule that was agreed to in 1949 had unintended effects less than one year later in the Korean conflict.
During the negotiations aimed at ending the fighting, it became known that some of the North Korean and Chinese soldiers who had been captured by the UN force did not want to be repatriated. In response to this development, the Communist delegation at the truce talks invoked Article 118, while the US proposed an alternative principle, “voluntary repatriation”, which would allow POWs to be interviewed and choose where they would be sent.Footnote 126 In deciding how to respond to the American position, British leaders faced a policy dilemma. Under the political circumstances of the nascent Cold War, with President Truman under domestic pressure to look strong in the fight against communism, it seemed unwise and unrealistic to forcefully send anti-communist POWs back to communist countries.
Further, leaders believed that it would be morally wrong for them to send men back to face possible punishment or death by what the West perceived to be oppressive regimes. For instance, UK Foreign Secretary Anthony Eden noted in February 1952 that, while the legal grounds for voluntary repatriation might be poor, this “doesn't make me like the idea of sending these poor devils back to death or worse”.Footnote 127 Going farther than Eden, recently elected Prime Minister Winston Churchill stressed one month later that the fate of the POWs in Korea involved considerations of “honour and humanity”, and they could not be turned over for execution or imprisonment.Footnote 128
And yet, notwithstanding the above political and moral concerns, Article 118 clearly stated that POWs shall be released and repatriated without delay after the cessation of active hostilities. To disregard this rule would have been inconsistent with Britain's former position in 1949 and, leaders worried, could have threatened the safety of British and Commonwealth POWs, and set a dangerous precedent for future wars. Resonating with these concerns, the UK Foreign Office expressed considerable scepticism about America's motives. As one official noted in January 1952, while there was an element of humanitarianism in the US approach, it was also strongly influenced by political and ideological factors.Footnote 129 On 23 April that year, a paper was drafted for the Cabinet on the POW issue. In it, J.M. Addis of the FO's Korea department argued that “if it should clearly come to the breaking-point our right course would be to accept an armistice at the cost of agreeing to the forcible repatriation of a number of Chinese and anti-Communist prisoners … I also feel that the humanitarian argument, that we could not have it on our conscience to force prisoners to return to death or slavery, has been given too much importance”.Footnote 130
The above suggests that, in deciding how to respond to America's position regarding POWs during the Korean truce negotiations, UK leaders faced a situation where political and moral factors pointed in one direction—i.e. support the principle of voluntary repatriation—and international law pointed in another—i.e. implement Article 118. If theorizing and observing a distinct nature and effect of international law is possible in IR and IL research, then this is arguably one such situation. Indeed, while Churchill rejected the Foreign Office's view, Eden sympathized with it.Footnote 131 Nonetheless, in the end, the government did not adopt the FO's position and instead decided to support the US stand on POWs. Explaining the decision in a letter to Clement Attlee on 1 May 1952, Eden wrote that “it would in my view be repugnant to the sense of values of the free world to send these men home by force”.Footnote 132
VII. CONCLUSION
The aspects of Britain's participation in the Korean War assessed above offer evidence in support of this study's main argument that, when countries use military force abroad, international law helps define and shape their possible course of action, and the justifications that can be made for their behaviour. More specifically, these aspects help illustrate the four roles that international law can play in the use of force—i.e. the constitutive, regulative, permitting and legitimating, and structuring roles outlined above.
With respect to my second hypothesis, the discourse and behaviour of British leaders and officials regarding the Korean conflict offer mixed support for the view that, when states use force, policy-makers understand international law as a distinct and binding set of legal rules, and the legal status of these rules impacts their decision-making. On the one hand, we saw that leaders and officials recognized that the use of force in Korea and the treatment of prisoners were in part legal issues, in that they were governed by pre-existing rules in the UN Charter and Geneva Conventions. Moreover, leaders and officials discussed the extent to which Britain was legally obligated to consider these rules when deciding whether and how to use force in Korea, and what policy to adopt regarding the repatriation of POWs.
Further, Attorney-General Shawcross acknowledged that the accepted rules of war should apply reciprocally in the conflict. Finally, leaders and officials recognized that Britain's involvement in the US-led intervention in Korea was subject to international legal critique, and required legal justification at the domestic and international level. The foregoing details resonate with most of the observable implications posited earlier, and suggest that many UK leaders and officials, but particularly Prime Minister Attlee and Foreign Secretary Eden, felt bound in part by international law.
On the other hand, because the Security Council recommended that help be provided to South Korea, leaders and officials tended to interpret the Council's resolutions on the Korean crisis more in political and moral, rather than expressly binding, terms. By contrast, a key POW obligation under the Third Geneva Convention, Article 118, was seen in distinctly legal terms. Recall, however, that the perceived requirements of this rule conflicted with other political and moral considerations at the time, and these factors appear to have ultimately exerted a greater impact on Britain than the law at issue.
In sum, my findings suggest that international law can play important roles in world politics and the use of force by states, but it is unclear whether these effects are ultimately attributable to an obligatory quality in law.
These findings are significant for existing theory in the fields of International Law and International Relations. They also highlight future research that could build on this work. First, insofar as this study demonstrated that international law played a role in situations where realists posit that states should be purely interested in maintaining their relative power position—i.e. in decisions about when and how to use military force—then this further supports the small but growing interdisciplinary research noted earlier that seeks to show that the relationship between international law and the use of force by states is more complex than realism might suggest, and that law can impact even “high politics” issues like war. Future work, however, could examine other cases,Footnote 133 and assess whether realist perspectives on law are more accurate. For example, although I argued that international law influenced Britain's involvement in the Korean War, law may have had less impact on the UK's colonial conflicts in KenyaFootnote 134 and Malaysia in the 1950s, and on Britain's involvement in the Iraq War of 2003.Footnote 135 More broadly, whether the effects of law in Korea can be seen in other examples will admittedly depend on the facts of each historical case, and thus caution should be exercised not to overly generalize this study's findings.Footnote 136
Second, inasmuch as this investigation outlined the four main roles that international law can play in the use force, this helps advance existing IR research that seeks to go beyond (a) demonstrating that normative factors matter in world politics and can affect state behaviour, to (b) specifying how such factors matter.Footnote 137 For example, constructivists have often focused on the constitutive effects of normative factors,Footnote 138 and some neoliberal institutionalist and constructivist work has assessed the constraining impact of such factors.Footnote 139 This study, however, showed that these factors can have two additional effects: they can permit and legitimate certain practices that otherwise might not be allowed, and structure the process by which agents seek to develop and promote new rules and legitimate conduct. The second of these additional influences, I would suggest, has been comparatively understudied in IR research to date, and is a fruitful area for further interdisciplinary work.Footnote 140
Third, in response to an important query posed by Martha Finnemore about whether legal norms are distinct,Footnote 141 this paper found that, in some circumstances, policy-makers do know and do care about the legal status of the rules they consider relevant to their decisions. We saw this when UK leaders and officials discussed, in great detail, whether the Security Council had “recommended” or “decided” under Article 39 of the UN Charter that assistance be provided to South Korea following North Korea's attack. We also saw this when they recognized that Britain's obligations under the Third Geneva Convention on POWs were engaged by the repatriation issue. This gives us reason to think that, in Finnemore's words, “legalness” can matter in compliance with norms. Future work, however, could assess more comprehensively why and when policy-makers do and do not care about the legal status of the rules they deem relevant to their decision-making.
Relatedly, as noted earlier, a number of observers posit that obligation is the defining feature of international law, and this binding nature helps law play a distinct role in world affairs. This paper sought in part to subject this fundamental conceptual assumption to qualitative empirical inquiry. Admittedly, as Martti Koskenniemi notes, the origin and operation of the concept of obligation are at best hard to observe or, at worst, a “mystery”.Footnote 142 Further, although a sense of obligation may be the main reason states tend to comply with international law, it is also likely one of a few reasons why they do so.Footnote 143 Finally, in addition to obligation, law may have other distinct institutional traits or effects.Footnote 144 As seen in the discussion of whether UK leaders saw the Korean conflict as a war or police action, the involvement of legal advisors may affect the way policy-makers view international law, and the impact that law has.Footnote 145 Future research could subject the above ideas to further theoretical refinement and empirical evaluation.
