ASEAN’s Evolving Institutional Strategy: Managing Great Power Politics in South China Sea Disputes

This article argues that a change in institutional strategy enables The Association of Southeast Asian Nations (ASEAN) to manage its great power relations and prevent their abrupt political intrusion into the region by providing the policy options of pur- suing institutional balancing, bandwagoning, hedging, or co-option. ASEAN’s strategy is not only to choose optimal policy under a changing security environment, but also to create an institutional division of labour by proliferating ASEAN-led institu- tions to ensure, as far as possible, regional autonomy and Member States’ security. Changes in ASEAN’s institutional strategy occur when its Member States expect a change in the regional distribution of power. However, due to constraints created by the existing institutional design it is difﬁcult to make any drastic alteration to the institutional strategy unless a radical change in the regional power conﬁguration occurs. This article examines the cases of East Asia Summit and ASEAN Defence Ministers Meeting (ADMM)/ADMM-Plus during the period 2005–2016, the compari- son of which illuminates the causes and processes of their strategy change and helps to deepen our understanding of the roles of regional security institutions.


Introduction
The Association of Southeast Asian Nations (ASEAN) is considered one of the most successful regional security institutions (RSIs). 1 However, scholars and practitioners have long debated ASEAN's utility as regards traditional security issues. This question has become particularly salient in view of the regional power shift caused primarily by China's rise, and in the context of recent debates over These explanations, however, are partial and unsatisfactory, because they fail to capture the evolving nature of the strategic roles of ASEAN and ASEAN-led institutions. For example, having secured a relatively high degree of interstate stability among ASEAN Member States during the Cold War, ASEAN's institutional effort to ensure security and stability in the post-Cold War period is no longer confined to Southeast Asia. As security interdependence in Northeast Asia and Southeast Asia has deepened, ASEAN has attempted to incorporate external powers into its rules and norms, creating multilateral political and security institutions such as the ASEAN Regional Forum (ARF), the East Asia Summit (EAS), and the ASEAN Defence Ministers Meeting Plus (ADMM-Plus). Although their institutional norms, such as the 'non-interference principle' and the 'consensus decision-making process', endure, ASEAN has also formulated a web of multilateral political and security institutions in East Asia that encompasses great regional powers, which implies the existence of a strategy that will enable the institution to cope with the external strategic environment. 6 However, this strategy shift has yet to be explored in the International Relations (IR) literature. The question, then, is: how does ASEAN, as an RSI, formulate/reformulate a strategy to manage its relations with regional great powers?
This article constructs an analytical model of the concept of an RSI institutional strategy and how it can change, in order to understand ASEAN's management of a traditional security issue, namely, that of the South China Sea. Here, institutional strategy refers to a collective security policy that RSI Member States pursue under the belief that such a policy can enhance their short-or long-term security. While Member States need to come to an agreement on forging an institutional strategy, given the principle of state sovereignty, such a strategy does not necessarily dictate the security policies of individual Member States. RSIs employ four types of institutional strategy-institutional balancing, bandwagoning, hedging, and co-option-and the one in use would likely change should the Member States expect either a radical or a moderate change in the regional balance of power.  80-95. 6 Here, security institution refers to a global or regional organisation that has a set of securityrelated rules and norms, which the Member States believe can translate into material or normative power useful to ensure their security. As this definition is broad enough to encompass various security arrangements, such as bilateral or multilateral 'collective self-defence', 'cooperative security', and 'collective security' arrangements, it enables us to examine and compare a broad range of security institutions in the international realm.
By means of this analytical model, the article argues that a change in institutional strategy enables ASEAN to manage its great power relations to prevent regional great powers from committing any abrupt, unsolicited political intrusion into Southeast Asia. ASEAN's strategy is not only to choose the optimal policy under a changing security environment, but also to create an institutional division of labour by proliferating ASEAN-led institutions to ensure regional autonomy and Member States' security. Changes in ASEAN's institutional strategy occur when Member States expect a change in the regional distribution of power in Southeast Asia. However, it is difficult to make any drastic alteration to institutional strategy due to the 'stickiness' of the existing institutional design.
This article examines the cases of EAS and ADMM/ADMM-Plus during the period 2005-2016. There are three primary reasons why these two institutions have been selected. First, they are the only multilateral strategic and security institutions at the government level to focus geographically on the same relatively narrow definition of 'East Asia.' The ARF was the first ASEAN security forum to include external states; however, its 27 members, as compared with the 18 countries in EAS and ADMM-Plus, constitute considerable geographical diversity, encompassing several regions of the world that include East Asia, South Asia, and Europe, which lessens the strategic focus on East Asia. Secondly, the two institutions share similar institutional formats, insofar as they have the same membership and have both undergone institutional developments involving their agendas, functions, and membership. Nevertheless, they have experienced different institutional growth-and the specific timing and functions of their institutional development highlight the process of divergences in the evolution of institutional strategy. Thirdly, these two institutions are ASEAN-led but exist independently within ASEAN. Therefore, the decisions they make do not significantly influence each other because the institutions are not organisationally linked. In this sense, the comparison between EAS and ADMM/ ADMM-Plus highlights the causes and processes of their strategy shift, which deepens our understanding of the roles of RSIs.
The article is in four sections. The first discusses the concept of institutional strategy, including types of strategies, the strategies' linkage with institutional change, and the degree of such changes. This section also introduces a theoretical model for the conditions and processes of changes in institutional strategy, employing the parsimonious version of agent-centred historical institutionalism. The second and third sections apply this theoretical model to EAS from 2005 to 2016 and to ADMM/ ADMM-Plus from 2006 to 2016, and illustrate the similarities and differences in their strategy shifts. Finally, the fourth section examines the results of the case studies and discusses ASEAN-led institutions' strategic implications for East Asia.

The Concept of Institutional Strategy and Change
Mainstream IR theories, namely, neorealism, institutionalism, and social constructivism, have different points of focus on international security institutions. Neorealism discusses the microcosm of a hierarchical order in the international politics of the day that exists within an institution, and assumes that states strategically establish security institutions to manage the balance of power essentially by balancing against or bandwagoning with dominant or rising powers. 7 Institutionalism and social constructivism discuss the creation of regulatory and constitutive norms whose diffusion is intended to influence external actors, as well as the intra-member relations of security institutions. 8 Although these insights are important, the IR literature rarely discusses the evolving strategic utility of security institutions, except in a few rare instances. 9 Among them, Wallander and Keohane sought a nuanced understanding of evolving institutional strategy by introducing two types of institutional objectives: counter-threat and counter-risk. 10 However, this analytical framework focuses more on the internal dynamics of the security institution that sustains itself, rather than on institutional strategy, employing the experience of the North Atlantic Treaty Organization (NATO) as a sole empirical case, which is not necessarily applicable to the institutions led by non-great powers. 11 Building on these preliminary analytical models, Cottrell developed a theoretical model of institutional change in security institutions. He articulates the evolving strategic roles of security institutions through institutional replacement by arguing that institutional continuity and change depend on whether institutional legitimacy is sustainable at a given moment in time. 12 His emphasis on the importance of legitimacy, moreover, provides us with new insight into the variances of institutional change in the security field. Still, Cottrell's focus is confined to a particular process of institutional changereplacement-and does not illustrate the formulation of or change in institutional strategy. 13 In short, IR studies face a paucity of conceptual and theoretical institutional strategy frameworks.
To fill such a gap in the literature, this article constructs an analytical model to deepen the understanding on institutional strategy. However, before doing so, it is necessary to clarify the basic functions of security institutions. First, the primary objective of a security institution is to ensure Member States' security. 14 Given the anarchic international environment, security is regarded as a scarce commodity. Member States within a security institution, therefore, value that institution's security utility. However, because both the concept of security and the degree to which 'security' is satisfactorily ensured depend on the actors' subjective judgment, an institution's sustainability is also subject to Member States' belief in its credibility. 15 Accordingly, if this belief weakens or collapses, Member States will consider either initiating an institutional change or discarding the institution entirely.
In the traditional security field, states build a security institution, such as a military alliance or diplomatic coalition, to formulate an 'institutional strategy' that shapes the balance of power in their favour. Institutional strategy is thus a collective security policy that the Member States of a security institution pursue under the belief that such a policy can enhance their short-or long-term security. There are four main types: institutional balancing, institutional bandwagoning, institutional hedging, and institutional co-option. 16 Institutional balancing refers to collective actions by members of a security institution that aim to neutralise, or at least minimise the current and expected power differences of a hegemon or rising power that is situated outside the institution. This concept is similar to the realists' 'external balancing', where a security institution mobilises political, economic, and military resources to create a balance against a target state(s). 17 However, due to their limited military capabilities, medium-or small-power-led security institutions, such as ASEAN, generally use political means to conduct balancing. This strategy can send a political signal not only to the target state(s) but also to the international community that the target state(s) is behaving 'illegitimately' or 'unjustly', potentially attracting international support, including that of the external great powers. Such a signal would then increase the possibility (which can function as a threat) that the international community will impose material punishment upon the target state(s). ASEAN's unified criticism (a joint statement) of Vietnam's invasion of Cambodia in 1979 is a case in point. Institutional bandwagoning refers to collective alignment with great powers, including the potential source of a threat, to gain benefits and ensure security at the expense of their institutional authorities and opportunities to cooperate with other powers. Institutionally, all Member States attempt to adopt a common stance with a target state(s), or at least not to object to such a stance, thus enhancing military, economic, and political cooperation. Member States also incorporate a target state(s) into the institution, providing it with authority and an opportunity to lead the institution, so that members can decrease the threat emanating from the target and gain benefits from the target's military, economic, and political resources. An example of this phenomenon is the Trans-Pacific Partnership (TPP), which originated in a 2005 economic agreement concluded by small powers such as Brunei, Chile, and Singapore, which were not necessarily formal allies of the United States. In 2008, the TPP included the United States, in the hope of increasing the agreement's security, economic, and political influence in the Asia-Pacific region and beyond. 18 Institutional hedging is an institutional action that incorporates a target state(s) into the institution as a member state, aiming to constrain the target state's behaviour by creating or consolidating institutional norms and rules. This strategy can maintain strategic ambiguity in order to reduce or avoid the risks and uncertainties of negative strategic consequences that would be produced by institutional balancing or bandwagoning alone. Institutional balancing and bandwagoning entail risks of clear policy failure. On the one hand, the failure of institutional balancing can lead Member States to experience severe punishment because such actions provoke the target state(s). On the other hand, failed institutional bandwagoning can lead Member States to confront the target state(s)' domination, and the loss of their autonomy and security. Both strategies also face the risk of the problem of commitment on the part of the ally or bandwagoned state. Therefore, security institutions combine balancing and bandwagoning to reduce these types of risks. How, then, can RSIs hedge against such risks? They generally do so through 'institutional power', which aims to 'exercise [control] indirectly over others through diffuse relations of interaction' by mobilising material or symbolic/normative resources. 19 In other words, RSIs use existing or new institutional rules and norms to constrain target state(s)' behaviour. This strategy can maintain a strategic ambiguity towards the target state(s) because the behaviour of all other Member States is similarly regulated by the same rules and norms. For example, ASEAN created the Treaty of Amity and Cooperation in Southeast Asia (TAC) in 1976, which set six basic principles as the code of conduct (COC) with regard to intra-Member State relations, including 'non-interference in the internal affairs of one another' and 'renunciation of the threat or use of force', and imposed these rules on new Southeast Asian members, such as Vietnam, during the 1990s. 20 As the institutional rules indiscriminately pose certain behavioural constraints on Member States, such actions, unlike institutional balancing or bandwagoning, are unlikely to be considered to target a particular state. However, this strategy is not entirely risk free. Strategic ambiguity may induce target state(s)' scepticism, and increase their incentive to defect from such institutional norms and rules whenever possible.
Institutional co-option is an institutional action that nurtures cooperative norms and rules by incorporating a target state(s) in the hopes of changing its preference. This strategy is based on 'productive power', a term that refers to 'the constitution of all social subjects with various social powers through systems of knowledge and discursive practices of broad and general social scope'. 21 Similar to institutional hedging, this strategy is also exercised by incorporating a target state(s) as a member and providing opportunities for Member States to interact diplomatically with each other. It is entirely possible for this policy to be strategically motivated, creating security norms and principles that are advantageous to core Member States. However, it does not aim to constrain the behaviour of the target state(s) through regulative norms. Rather, it expands channels of communication, facilitates cooperation generally in non-contested areas, and increases the possibility of nurturing cooperative norms and rules with all parties' consent. To this end, Member States can avoid addressing any contentious issues that may exist between them, such as territorial disputes. The functions of a 'cooperative security' arrangement, which emphasises the importance of confidence-building measures (CBMs) through diplomatic interactions and policy discussions towards potential cooperation, provide examples of institutional co-option. The case in point is the ARF. While ASEAN initially considered the establishment of the ARF as an institutional hedging tool by including in it both China and the United States, its agreed primary and initial objectives were to act as CBMs, and not to impose rules on Member States, as was consensually decided in the second meeting that issued the concept paper. 22 These four strategies provide a security institution with options for ensuring Member States' security. An institutional strategy can be altered, depending on the strategic situation and Member States' security interests.
One important caveat is in order. Institutional strategy, unlike state strategy, is relatively inflexible when it comes to change. This is because the collective action issue makes it difficult for Member States quickly to achieve a certain consensus or agreement on changing institutional objectives, functions, rules, or norms. Additionally, a change in institutional strategy would affect the institution's design and format, so creating significant security implications for each member state that would make them highly cautious of such a move. 23 For example, a cooperative security institution based on institutional co-option, such as the ARF, will find it difficult to transform itself into a collective self-defence system based on institutional balancing, such as NATO, unless there is a radical shift in the strategic environment that defies Member States' belief in and commitment to the institution. There are close links between institutional strategies and institutional change, as breaking through this type of 'stickiness' of institutional strategy requires institutional change.
Then, when and how does such an institutional change occur? While the frequency of institutional change is not high, assuming that there are two types of institutional change that affect institutional strategy, namely, radical and moderate, we can observe that there are more moderate changes than radical ones. 24 22 ASEAN Secretariat, 'Chairman's Statement of the 2 nd Meeting of the ASEAN Regional Forum, Brunei Darussalam, 1 August 1995', http://aseanregionalforum.asean.org/library/arfchairmans-statements-and-reports.html?id¼131; ASEAN Secretariat, 'The ASEAN Regional Forum: A Concept Paper', http://aseanregionalforum.asean.org/files/library/Terms%20of %20References%20and%20Concept%20Papers/Concept%20Paper%20of%20ARF.pdf. 23 Examining internal political dynamics of decision-making procedures inside ASEAN, Tan argues that despite consensus-decision-making procedures and lack of an enforcement mechanism, ASEAN utilizes peer pressure to create a unified political stance and policy, which might generate institutional change; therefore, such a process is always painstaking. See Seng Tan Incorporating four types of institutional strategy in this context, we can draw a conceptual map of the occurrence of change ( Figure 1).
There is only one type of radical change, and that is to shift the institutional strategy from balancing to bandwagoning, and vice versa. The radical shift in institutional strategy derives from an expected radical change in the strategic environment, such as an expectation of war, or collapse of a great power. However, an institution can experience a variety of moderate changes in its strategy. This moderate shift occurs when Member States expect either an abrupt or a gradual change in the strategic environment. Under a gradually changing environment, institutions would likely avoid disrupting the strategic environment by abruptly shifting their institutional strategy. Therefore, rather than radically shifting their institutional strategy between balancing and bandwagoning, Member States will gradually modify their strategy from balancing to hedging or cooption, or lean from hedging or co-option towards bandwagoning or balancing. At the same time, it is also possible that, when Member States face immediate change in the strategic environment, the institution could make a moderate change abruptly.
That said, some institutional strategies can co-exist while others cannot. Specifically, a shift between hedging and co-option represents an institutional adjustment rather than an institutional change, because little institutional modification is required between creating regulative norms and rules on the one hand, and nurturing cooperative norms on the other. As such, institutional hedging and co-option can co-exist. However, institutional balancing functions only when the institutional membership is exclusive to the target states, which contravenes other strategies. Furthermore, institutional bandwagoning and hedging/co-option cannot co-exist. As institutional bandwagoning includes the target states and defers institutional authority, such as decision-making power and the leadership role, there is a little room for the original Member States to use the institution politically vis-à -vis the target states. Indeed, as Figure 1 shows, once an RSI conducts institutional bandwagoning, it will be more difficult to shift its policy back to any

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The Chinese Journal of International Politics, 2018, Vol. 11, No. 1 of the other strategies. This is because the target states eventually have authority over the institution, and unless the target states defect from the institution, or the original Member States somehow manage to purge the target states, it will be difficult, if not impossible, to change its institutional strategy. Likewise, once the institution includes the target states, it becomes more difficult to shift from institutional hedging/co-option to institutional balancing. Generally, these changes in institutional strategy occur when Member States of an RSI expect a change in the regional balance of power. However, an expected strategic environmental change is not the sole determinant of a shift in international strategy, because ultimately it occurs from within, thereby implying agency. As agent-centred historical institutionalism illustrates, institutions are 'ontologically prior to agency', but it is emphasised that agency is 'a prime mover in institutional change processes'. 25 Accordingly, it does not give complete primacy to agents over institutions or the environment. Agents do not act on a tabula rasa when there is an environmental change; instead, they strategically act under the influence of previous and existing institutional rules and norms. This approach sheds light on the process of change in institutional strategy-an environmental change opens the window of opportunity for a change in institutional strategy; Member States reassess its existing institutional utility or raison d'etre and alter or maintain the strategy to cope with a new strategic environment.
More specifically, an environmental change can be equated with a perceived change in the regional distribution of power. This is because a security institution's fundamental objective is to ensure Member States' security by maintaining strategic stability in the immediate environment. Strategic instability, such as the emergence of a power vacuum or a change in a major power's foreign policy, propels Member States to respond effectively to restoring stability. Strategic instability is 'perceived' because a security institution's sustainability is ultimately based on Member States' belief that the institution is useful for their security. To sustain this belief, it is necessary for members to evaluate the institution's utility vis-à-vis the changing strategic environment. In addition, the type of security institution is significant. For example, it is highly unlikely that ASEAN will be useful in managing other regions' security, such as Africa's, because ASEAN's core geographic focus is on Southeast Asia. In this sense, Member States' perception of the regional distribution of power and their belief in an institution's security utility have become two important factors that can cause a change in international strategy.
The corollary of this is four-fold. First, Member States' perception of the degree of a change in the regional distribution of power corresponds to the degree of institutional change. This does not mean, of course, that the perception of change is a sufficient condition for a shift in institutional strategy. It only creates a window of opportunity because the decision on such change is ultimately made among Member States. However, the larger the degree of change that Member States perceive, the wider the window of opportunity is likely to open. Secondly, the speed of environmental change would affect the speed of change in institutional strategy. For example, moderate change can be either abrupt or gradual, depending on how Member States perceive a change in the regional distribution of power. Radical change, however, occurs only in the face of an abrupt change in the regional distribution of power, because a gradual environmental change cannot provide incentives sufficient for RSIs radically to change institutional strategy at the risk of political provocation of great powers. Thirdly, Member States' reassessment of the institution's security utility directs a certain type of institutional strategy, because Member States must recalculate whether and how the security institution can mitigate the potentially negative effect of a strategic shift, and employ a cost-benefit analysis to evaluate the level of institutional utility. Fourthly, institutional design-be it cooperative security, collective selfdefence, or collective security-functions as a political constraint on institutional strategy. Therefore, the only institutions that can make a radical change are those that engage in institutional balancing or bandwagoning. If institutions engage in hedging or co-option by design, their strategic changes all become moderate. Two unanswered questions arise regarding Member States of ASEAN-led institutions: who is the main agency; and once ASEAN includes external powers in the institutions, do the dynamics of their decision-making process change? To answer the former question, the agency is ASEAN. As ASEAN's institutional norms-ASEAN Centrality, which ensures ASEAN's privileges of chairpersonship and agenda-setting of the meeting, and the consensus decision-making principleensure that any decision made in the ASEAN-led institutions should reflect Member States' consensus, ASEAN is the pivotal player. The answer to the latter question is mixed. On the one hand, ASEAN has created and embedded the principle of ASEAN Centrality to prevent external powers from hijacking ASEAN-led institutions. So far, this principle has been applicable to all ASEAN-led institutions, including ARF, ASEAN þ 3, EAS, and ADMM-Plus, and thus, ASEAN remains the main actor in the decision-making process in ASEAN-led institutions. 26 However, ASEAN's decision-making process is consensus-based, and each member virtually possesses a veto power. In this sense, it becomes more difficult to reach consensus on contentious issues, such as territorial disputes, because the number of participants with divergent interests increases. Therefore, ASEANled institutions would likely face difficulty in reaching consensus over such issues. According to this analytical framework, the next section examines the evolution of the institutional strategy of EAS and ADMM/ADMM-Plus. Methodologically, identifying a change requires at least two points of reference within a certain time frame. These two points can be referred to as the 'reference point' (t1) and the 'comparative point' (t2). The 'reference point' is the original point of assessment, whereas the 'comparative point' is the point of comparison. Because change is inherently defined in relative terms, these two points must be clearly identified and compared. Both t1 and t2 identify the institutional strategy. Next, the nature of the perceived regional strategic shift from t1 to t2 will be examined. The application of this method helps to compare each case clearly and systematically, and uncovers a general causal inference of change in institutional strategy. The method mainly uses official documents, including joint communiqués and joint declarations, pertaining to EAS, ADMM, and ADMM-Plus from 2005/2006 to 2016, while also examining media reports appearing in newspapers and magazines to understand the nuances of those changes. Given ASEAN's strict consensus decision-making mechanism, ASEAN-led institutions will not issue any consensual documents, such as joint communiqués and joint statements, if there is clear disagreement by a member state. Therefore, it is safe to assume that the contents of these documents The East Asia Summit (EAS) was established in 2005 (t1). EAS was essentially a byproduct of political compromises among Member States, and initially there was no consensus with regard to its institutional objectives, agendas, or modality. This is partly because proposals by ASEAN Member States differed from what was originally planned in the recommendations submitted by the East Asia Vision Group (EAVG) and the East Asia Study Group (EASG), the study groups under the ASEAN þ 3 authority-which envisioned a long-term upgrade of ASEAN þ 3 into an East Asian Summit. 28 Soon after the EASG report came out, however, Malaysia took the initiative to establish an East Asian summit. China supported this initiative while also aiming to play a leading role in the ASEAN þ 3-centred community-building in the region by holding the first (after rejection, then second) summit. 29 Fearing China's growing influence over ASEAN and East Asia, Japan and Indonesia moved to water down this political initiative by proposing membership expansion and emphasising ASEAN as a driving force in the institution. 30 These divergent political stances created a political tug-of-war among members of ASEAN þ 3, particularly Malaysia and China, on the one hand, and Indonesia, Singapore, and Japan on the other. 31 Eventually, this resulted not only in membership expansion to include Australia, India, and New Zealand, but also enormous political confusion, to the extent that Member States were unable to reach consensus on the initiative's core objectives. The first summit produced only a vague declaration, and focused on non-contentious potential cooperation, avoiding traditional security issues that would create diplomatic tensions between Member States. 32 EAS eventually sought areas of cooperation, rather than behavioural constraints on Member States; therefore, ASEAN adopted institutional co-option vis-àvis the regional great powers, namely, China and Japan, through EAS.
By 2016 (t2), EAS had extended its membership to the United States and Russia, while leaving its internal principle, ASEAN Centrality, intact. Furthermore, its agenda explicitly included specific security issues, such as maritime security, emphasising freedom of navigation and the principles of international law in the East and South China Seas. 33 Having expanded its membership and included traditional security agendas, EAS thus became a leaders-led forum that could discuss traditional security issues more than possible in the past, and which involved institutional hedging vis-à -vis the United States and China while maintaining institutional co-option.  34 EAS was no exception. EAS's non-traditional security cooperation was developed into 'priority areas of cooperation', such as energy, climate change, and disaster relief, which would likely induce cooperative behaviour from Member States. This framework resulted in EAS declarations and statements, such as the 'Cebu Declaration on East Asian Energy Security' in 2007, the 'Singapore Declaration on Climate Change, Energy and the Environment' in 2007, and the 'Cha-am Hua Hin Statement on East Asia Summit Disaster Management' in 2009. Discussion of the possibility of a Japan-proposed East Asia free trade area among Member States later evolved into the Regional Comprehensive Economic Partnership. Furthermore, none of the Chairman's Statements or documents touched on sensitive issues among EAS members, which implied that members did not discuss the South China Sea in the meetings. This is partly because EAS would likely lose its political momentum towards regional cooperation and be cut adrift if further confusion occurred as a result of addressing traditional security issues, in the context of the 2006 and 2009 postponements of the summit due to the typhoon in the Philippines, and the Songkran political crisis in Thailand, respectively. Therefore, ASEAN Member States avoided being overly contentious and attempted to facilitate cooperation in those non-contentious fields. The initial objective of establishing the EAS-nurturing cooperative norms among EAS members-thus remained the same during this period. Obviously, the United States was concerned about its exclusion from EAS membership; however, the country was also cautious about joining the EAS at that point due to its political concerns about signing ASEAN's TAC, one of the criteria for EAS membership, and which, because it was similar to a non-aggression pact, might constrain US behaviour in East Asia. 35 This US non-involvement, in turn, made ASEAN Member States sceptical about the US's long-term commitment to Asia, particularly Southeast Asia. 36 For this reason, ASEAN Member States continuously pursued institutional co-option with Japan and China.

Second Phase: 2010-2016
The year 2010 witnessed a visible shift in the EAS's institutional strategy, but this was a trend that had become apparent in 2009. ASEAN Member States' expectations of a shift in the regional distribution of power in East Asia became more acute when China demonstrated its economic resilience to the 2008 global financial crisis and began to gain confidence by virtue of its alternative economic style, the 'Beijing Consensus', which would be seen as a challenge to the existing US-led 'liberal international order'. 37 Furthermore, the United States was inclined to increase its commitment to East Asia, primarily due to scepticism about China's intentions and behaviour with regard to the South China Sea after Chinese vessels harassed the US naval ship Impeccable on 8 March, 2009. In response, the United States insisted that freedom of navigation should allow military vessels to engage in non-threatening activities without the permission of littoral states, and that the safety of such practice be ensured in the Exclusive Economic Zone (EEZ) in accordance with the United Nations Convention on the Law of the Sea (UNCLOS). China interpreted the convention differently, and demanded that foreign states ask China's permission to conduct military activities within China's EEZ. 38  subsequently assertive behaviour, such as sending its largest and most modern patrol ship Yuzheng 331 to the South China Sea, became regionally recognised. 39 Furthermore, the 2009 Commission on the Limits of the Continental Shelf (CLCS) incident increased tension among claimant states. The CLCS deadline for submissions concerning, 'the outer limits of the continental shelf beyond 200 nautical miles' created the political momentum for claimant states to conduct a fait accompli strategy. For example, the Philippines' domestic law to ensure its territory, maritime border, and EEZ-the 'baseline bill'-was passed in April, creating diplomatic disputes with China. 40 The Vietnam-Malaysia joint submission also raised concerns among China and other claimant states, resulting in China's rejection of the joint claims and counterclaims regarding its own historical title over the South China Sea, the so-called 'nine-dash-line'. 41 The year 2009 thus sowed the seeds of behavioural change among regional states.
More visible diplomatic disputes and tensions over the South China Sea appeared at the beginning of 2010. When China enhanced its maritime patrol and captured Vietnamese fisherman, Vietnam declared its firm intention to defend its territories, and began to strengthen its air and naval capabilities by acquiring 6 Kilo-class submarines and 12 Su-30s. 42 The United States began to address the South China Sea issue more directly after Secretary of State Hillary Clinton was informed that high-ranking Chinese officials considered the South China Sea to be China's 'core interest'. 43 This manoeuvre was implied when Secretary Clinton raised the issue in the 2010 ARF meeting, and was supported by 12 Member States, including Japan, Indonesia, Vietnam, and Australia. 44 In this context, ASEAN Member States gradually began to have doubts about the feasibility of the implementation of the 2002 DOC, China's future behaviour in East Asia, and thus the status quo stability of East Asian security which had been affected by the gradual shift in the distribution of power. 45 Initially, ASEAN Member States considered EAS's institutional co-option sufficient to ensure China's compliance with EAS norms. As previously discussed, China had signed the TAC in 2003, well before the establishment of EAS, whose principles included the 'settlement of differences or disputes by peaceful means' and 'renunciation of the threat or use of force'. 46 China also accepted ASEAN Centrality, and supported ASEAN's effort to facilitate cooperation among EAS Member States. 47 Consequently, in 2007, ASEAN was able to create five EAS 'priority areas'. 48 ASEAN subsequently concluded the 2007 Cebu Declaration, which institutionalised the energy ministers' meeting, 49 along with the 2007 Singapore Declaration, which focussed on climate change, energy, and the environment. 50 Accordingly, ASEAN recognised some institutional merit in facilitating functional cooperation among EAS Member States, including China.
Nevertheless, rising diplomatic and military tensions in the South China Sea demonstrated that ASEAN's initial efforts had not been effective in shaping China's behaviour, because the existing arrangement failed to induce China's selfrestraint. Accordingly, ASEAN leaders, by and large, became increasingly uncertain about EAS's security utility. Some ASEAN Member States, particularly Vietnam and the Philippines, were even more alarmed by developments in the South China Sea situation, and seriously considered expanding EAS membership to external great powers, specifically the United States, to check China's rise. At this point, the United States also showed a clear interest in reaffirming its political and security commitment to East Asia, partly in response to China's assertiveness, and partly in an attempt to dispel Asian concerns about potential US disengagement. Secretary Clinton signed the TAC on 22 July, 2009, pursuant to which the United States became eligible for EAS membership and communicated US interest in joining EAS. In April 2010, ASEAN discussed the potential membership of the United States. Considering Vietnam's traditional strategic linkage with Russia, Vietnam was also willing to include Russia, as its participation would serve Vietnam's security interest. Thus, in October 2010, ASEAN decided to issue a formal invitation to both Russia and the United States to join EAS. 51 Incorporating two regional powers into EAS constitutes ASEAN's strategy shift from institutional co-option to institutional hedging, whereby ASEAN endeavoured to constrain the behaviour of its Member States, particularly that of the United States and China, through political means. ASEAN thus attempted to lock in US commitment to Southeast Asia, but in the context of Clinton's contentious speech at the 2010 ARF, and the subsequent US 'pivot' and 'rebalancing' policy towards Asia, US involvement in EAS also underlines the US willingness to check China's behaviour, particularly in the South China Sea. 52 This diplomatic signal of US inclusion, however, was not strong enough to alter China's assertive behaviour.
Consequently, EAS strengthened its institutional principles, and in 2011 ASEAN members created institutional guidelines for state behaviour, the so-called 'Bali Principles.' 53 Although it made no mention of the South China Sea, the document reiterated the importance of international principles, such as respect for international law, renunciation of the threat or use of force, and peaceful settlement of differences and disputes. 54  document, while intimating that there would be informal discussions on the South China Sea issue despite China's objection to US 'interference'. China then offered to engage in further negotiations with ASEAN over the COC. 55 In so doing, EAS Member States gradually institutionalised the 'informal' South China Sea agenda and consolidated institutional principles that may be used as justification for other great powers, such as the United States and Japan, to criticise China's assertive behaviour as and when it occurs. 56 Further, EAS has consistently discussed South China Sea issues in both the foreign ministers meeting and the summit since 2013. 57 This change was apparent. US involvement in EAS encouraged some ASEAN Member States and non-ASEAN Member States, such as Vietnam, the Philippines, and Japan, to discuss the issues because they shared similar concerns about the development of the situation. In 2015, the 10th anniversary of EAS, EAS foreign ministers discussed additional details regarding the situation in the South China Sea, such as land reclamation, and created the 'the South China Sea' category in the Chairman's Statement to provide an opportunity for extensive discussion of the issue. 58 Admittedly, EAS has still fallen short of issuing a joint statement, and has faced political difficulties in maintaining a unified front among ASEAN Member States.
Indeed, even within ASEAN, Member States' views on the South China Sea have differed, as in the instance of the 2012 Philippines-Cambodia disagreements over the statement on the South China Sea issue in the ASEAN joint communiqué. 59 The 2016 South China Sea Arbitration award failed to create sufficient political momentum for ASEAN to issue a joint statement. However, this does not mean that ASEAN will continue to be hesitant about discussing the matter. Depending on the strategic situation, ASEAN still has diplomatic room to use EAS extensively to ensure stability in the South China Sea. As such, ASEAN has gradually consolidated institutional hedging policy within EAS.
In sum, in 2010 ASEAN aimed to lock in US commitment to East Asia and increase EAS's political credibility. In the face of China's growing assertiveness, ASEAN's strategic objectives included ensuring the US presence in East Asia, informing the United States of China's manoeuvring in the South China Sea, and signalling to China that the United States and East Asian states would be able to monitor and check its behaviour in the maritime domain. Consequently, the South China Sea agenda has been informally yet gradually institutionalised in EAS in the wake of the formal US participation in 2011. In this sense, from 2005 (t1) to 2016 (t2), the expected change in the regional distribution of power caused by the rise of an assertive China moved ASEAN Member States to reassess whether EAS's existing institutional co-option was effective in taming China. As China's increasing assertiveness implied the limitations of EAS's effectiveness, uncertainty emerged about EAS's security utility. Therefore, with the aim of pursuing institutional hedging vis-à -vis China, ASEAN created an institutional structure within which the United States and China could check and balance each other's geopolitical influence in the region.
Nonetheless, it is also important to note that EAS's institutional strategy is more of an adjustive than a radical or moderate change. Since its original institutional strategy is co-option, institutional hedging is relatively easier for EAS to conduct than institutional balancing or bandwagoning. In 2006, ADMM aimed to nurture ASEAN Member States' cooperative behaviour by creating defence-related norms and rules among ASEAN Member States. Therefore, ADMM was an intra-ASEAN cooperative security arrangement, conducting institutional co-option towards intra-member relations. As the concept paper stipulated, ADMM was intended to be open to external actors, namely, its dialogue partners. A decade later, in 2016 (t2), two main institutional changes were observed. One was the establishment of ADMM-Plus in 2010, which was also institutional co-option due to the inclusion of eight ASEAN dialogue partners, namely, Australia, China, India, Japan, New Zealand, Russia, South Korea, and the United States. Given its strict adherence to ASEAN Centrality, ADMM-Plus focuses on promoting defence cooperation related to non-traditional security issues, such as maritime security, counter-terrorism, disaster management, peacekeeping operations, and military medicine (MM). ADMM-Plus became a regionwide, defence-oriented cooperative security arrangement whose aim was to become an action-oriented institution that would facilitate practical defence cooperation among its Member States. 62 These areas are also supported by the Experts' Working Groups (EWGs) under the supervision of ADMM-Plus. The second institutional change involves ADMM's political functionality. Since 2011, ADMM has begun actively to discuss the South China Sea issue in its joint declarations. Therefore, ASEAN members have added a new strategic role for ADMM to enact wherein it politically conducts institutional balancing vis-à -vis China by expressing its shared concern over the South China Sea while continuing to pursue institutional co-option towards ASEAN Member States.
Two Under this strategic environment, ASEAN decided to establish ADMM-Plus. Therefore, China's rise was not the immediate motivation for the creation of ADMM-Plus. This is implied by ASEAN's discussions in the pre-ADMM period, including the Bali Concord II statement on 'actively engaging ASEAN's friends and Dialogue Partners', the VAP statement on 'engagement with Dialogue Partners and friends', and ADMM's emphasis on the importance of interaction with dialogue partners, all of which envisioned the establishment of a defence-link with external states well before ADMM was established. 63 Moreover, ASEAN aimed to obtain material assistance for capacity building from economically and militarily capable dialogue partners to address 'transnational security' issues. 64 In this context, ADMM-Plus had three-fold situational utility for ASEAN Member States. First, ADMM-Plus allows ASEAN members with 'differing capacities' in 'addressing shared security challenges' to tap into the economic and defence resources of dialogue partners such as China, Japan, and the United States, which could 'work with ADMM to build capacity'. 65 Secondly, ADMM-Plus provides a focal point to promote confidence building and actual defence cooperation in the non-traditional security fields. Thirdly, ASEAN can maintain strict adherence to the norm of ASEAN Centrality in ADMM-Plus. 66 Whereas ASEAN Member States considered interaction with external states in East Asia to be beneficial, they also needed to prevent political marginalisation by external states. Accordingly, they took a firm stance in placing the ADMM at the 'centre of ADMM-Plus' so that it could institutionally prevent dialogue partners from hijacking it. 67 With these three institutional utilities, ASEAN Member States attempted to pursue institutional co-option vis-à -vis extra-regional great powers through ADMM-Plus.
To be sure, the ADMM-Plus establishment process was still under consideration in 2007, because it needed to be undertaken 'at a pace comfortable to all [ASEAN Member States]'. 68 Postponement of ADMM-Plus's establishment was entirely possible, and a relative sluggishness in materialising formulation of ADMM-Plus was indeed observed during the 2007-2009 period, even though the idea of the organisation had existed since 2007. 69 Furthermore, the third ADMM meeting, which was to be held in Thailand in 2008, was postponed because of the 2008 political crisis. 70 The most important change to occur, however, was that with regard to the speed of ADMM-Plus's establishment. As China's growing assertiveness over the South China Sea became gradually apparent in 2009, ASEAN members expected ADMM's utility to be positive, because ADMM-Plus was largely seen as a defence-oriented cooperative security arrangement that would be able to function as CBMs, enhance defence cooperation with China in a multilateral setting, and potentially diffuse tensions over the South China Sea.
From 2009 to 2010, therefore, ASEAN members expedited the process of establishing ADMM-Plus on the basis of ASEAN Centrality and institutional cooption. In 2009, ADMM created three criteria for membership-a full-fledged dialogue partner, significant interactions and relations with ASEAN defence establishments, and the ability to work with ADMM to build capacity to enhance regional security in a substantive manner-and determined that ADMM would have full control over the membership admission process. 71 In 2010, discussion on ADMM-Plus gained further political momentum when Vietnam became the Chair of ASEAN. Vietnam was concerned about China's behaviour in the South China Sea due to its direct involvement in the dispute, and was eager to bring external powers-Russia and the United States-to the region. 72 Vietnam thus took the initiative and reached consensus on recommending eight states for ADMM-Plus, including the United States and China, all of which became founder members. 73 As originally planned, ADMM-Plus was established, based on institutional co-option, to nurture cooperative behaviour among members.
In fact, the Ha Noi Joint Declaration, the first ADMM-Plus joint statement, did not discuss the South China Sea issue. Instead, the declaration emphasised defence diplomacy and joint exercises to facilitate comprehensive confidence building among members. 74 The 2010 ADMM joint declaration indicated that the role of ADMM-Plus was to assist ADMM in matters of regional security in Southeast Asia and beyond to the field of transnational security issues, stating that ADMM-Plus was 'a robust, effective, open, and inclusive component of the regional security architecture that would enable ADMM to cooperate with non-ASEAN countries to build capacity and better prepare ASEAN to address the complex security challenges'. 75 Therefore, there was less of an expectation within ADMM that ADMM-Plus would directly address traditional security issues such as disputes over the South China Sea. In addition, ASEAN defence ministers reconfirmed that ADMM-Plus could serve to facilitate confidence building, capacity-building, and cooperation on non-traditional security issues. 76 Nevertheless The establishment of ADMM-Plus affected ADMM's original institutional strategy-institutional co-option-and has shifted its political posture since 2011, when the South China Sea issue became more contentious. This shift is clearly illustrated in ADMM's joint declarations from 2011. From 2006 to 2010, ADMM joint declarations consistently focussed on the importance of defence cooperation over non-contentious, non-traditional security issues, proposing several initiatives for cooperation, such as Indonesia's 'Roadmap for the Use of ASEAN Military Assets and Capacities in Humanitarian Assistance and Disaster Relief', Thailand's 'approaches and mechanisms for enhancing the cooperation between ASEAN defence establishments and civil society organisations in the region', and Malaysia's 'cooperation in defence industry among ASEAN Member States'. 78 However, it was the 2011 joint declaration that first discussed the South China Sea by stating that the issue should be managed through international law, including UNCLOS, while encouraging the adoption of a regional Code of Conduct in the South China Sea (COC). 79 Since then, ADMM joint declarations have repeatedly emphasised the importance of implementing the DOC and adhering to international law. 80 Particularly since 2013, these declarations have cited in detail relevant official documents vis-à -vis stability in the South China Sea, including ASEAN's Six-Point Principles on the South China Sea, the Joint Statement of the 15th ASEAN-China Summit on the 10th anniversary of the DOC, and the 22nd ASEAN Summit's support for the early conclusion of the COC. Bearing in mind that a joint declaration is a consensual document that no ASEAN member state opposes, such a statement demonstrates ASEAN's general stance on the South China Sea and implicitly indicates its institutional stance visà -vis China.
To buttress its political statements, ADMM has also begun to create practical mechanisms to facilitate stability in the South China Sea among ASEAN Member States. ADMM's foremost contribution is the establishment of a direct communications link (DCL), which enables each member state to communicate bilaterally with another. 81 The DCL's primary purpose is to manage non-traditional security crises such as terrorism and natural disasters, yet ADMM noted that the DCL could be utilised as a crisis-avoidance mechanism, even in the traditional security field. 82 In addition to the DCL, ADMM attempted to consolidate its efforts through the Code for Unplanned Encounters at Sea (CUES), and by creating new protocols. 83 Considering the divergent interests existing within 'Plus' states, ADMM spearheaded the creation of its own common ground by creating a crisismanagement mechanism.
This type of ADMM behaviour indicates its cautious institutional balancing towards China. Repeated statements on the South China Sea, beginning in 2011, showed ASEAN's increasing political concern about the tense situation as a result of China's land reclamation and militarisation of the occupied shoals and reefs, and called for 'self-restraint', 'non-use of force', and to 'refrain from taking actions that would further escalate tension'. 84 One serious limitation was that ADMM continued to avoid naming-and-shaming even after serious events such as the 2012 Scarborough Shoals incident, and there has been no alternative policy whereby ASEAN may address the issue directly and effectively. ASEAN members hoped that such a loosely unified stance would act as a diplomatic signal to induce China's self-restraint. Nevertheless, ADMM behaviour can be still considered as a more advocative posture vis-à -vis the South China Sea issues than other institutions, namely, ADMM-Plus and EAS.
In the meantime, ADMM-Plus's functionality remained the sameencouraging the 'Plus' countries' assistance for capacity building while promoting confidence building through defence dialogues. It continued to promote cooperative frameworks for non-traditional security issues by creating the five EWGs, US-ADMM dialogues beginning in 2011 and the Japan-ADMM dialogues beginning in 2014. 89 To negate the risk of each great power's excessive influence over ADMM's political control with respect to setting the ADMM-Plus agenda, in 2014 and 2015 ADMM created two official documents, respectively: 'the Additional Protocol on the Concept Papers for the Establishment of an ASEAN Defence Ministers' Meeting (ADMM) and the ASEAN Defence Ministers' Meeting Plus (ADMM-Plus)'; and 'Guidelines to Respond to the Request for Informal Engagements or Meetings by the ADMM-Plus Countries'. Both documents emphasised the norm of ASEAN Centrality, making 'ADMM þ 1' meetings informal, limiting the number of meetings to two a year, and strictly limiting the decision-making authority of external powers. 90 Thus, ADMM-Plus remained a cooperative security arrangement compelled to remain politically uncontentious with respect to strategic dynamics among Member States.

Conclusion
How does ASEAN, as an RSI, formulate and reformulate its institutional strategy to manage its relations with regional great powers? With regard to EAS and ADMM/ADMM-Plus, ASEAN employed different strategies in these institutions. The commonality lies in ASEAN's view on the strategic environment in Southeast Asia. This is evident in the timing of the development from 2005 to 2016 of EAS and ADMM/ADMM-Plus, which, given their shared geo-strategic focus on East Asia, was similar. Both institutions had been affected one way or another by the rise around the year 2010 of an assertive China. This expected change in the regional distribution of power opened a window of opportunity for a change in the EAS and ADMM institutional strategies. However, due to differing institutional designs, China's assertiveness produced different outcomes at different times. ASEAN Member States became increasingly uncertain about EAS's cooperative security utility vis-à -vis China, and pursued institutional hedging by including the United States and Russia in its membership. However, ADMM expected a positive effect from ADMM-Plus, and conducted institutional co-option because this offered tangible military cooperation, and would accelerate the establishment of ADMM-Plus. Nevertheless, as China's assertiveness continued, Member States perceived ADMM-Plus's security utility as limited, and ADMM formulated a weak form of institutional balancing vis-à -vis China. In other words, ASEAN utilised different institutions in an attempt to cope with regional great powers.
This cross-case analysis also reveals that each security institution formulated a new institutional strategy to shape ASEAN's relations with regional great powers in its favour, in the context of an expected shift in the distribution of power in East Asia, which produced six major findings. First, not all ASEAN-led institutions have avoided traditional security issues. Although ASEAN's military weakness vis-à -vis regional great powers remained constant, the expected change in the strategic balance as a result of China's increasing assertiveness created an incentive for ASEAN Member States to manage China's behaviour politically through EAS and ADMM-Plus. Admittedly, the limited practicality of this persists, even though some ASEAN Member States have attempted to create a stronger coalition vis-à -vis China with regional powers, including the United States and Japan. However, ASEAN responded to and attempted to manage traditional security issues by shifting its institutional strategy, which was contrary to the conventional wisdom that emphasises ASEAN's avoidance of traditional security issues. ASEAN adopted various political means either to mitigate tension or to reinforce the principles that illegitimatise a potential intruder into Southeast Asian affairs.
Secondly, an original security arrangement affects Member States' reassessment of security utility. The original purpose of the institution is significant because it becomes the reference point through which to assess whether the institutional objective is being appropriately pursued by the existing institutional arrangement. As illustrated by the ADMM/ADMM-Plus cases, ADMM-Plus was designed and established to pursue institutional co-option toward East Asian states. Given this original purpose, it became difficult to shift ADMM-Plus's institutional strategy abruptly to that of institutional balancing without causing an abrupt change in the regional distribution of power, even when ASEAN Member States perceived the limited utility of ADMM-Plus in the face of China's assertiveness in the South China Sea. ADMM was able to improvise its external policy without institutional constraints because its fundamental organisational approach was to strengthen intra-member relations, and it had no specific external policy. The existing arrangement, therefore, functions as a constraint and narrows the range of policy options it can adopt.
Thirdly, a strategy shift is generally difficult because divergent interests exist among Member States. A number of political compromises have hence been made among Member States that permit the issuance of consensual statements. Given this, Member States are generally cautious about strategy shifts, since they would have a profound effect on the utility of the institution. This partly explains why ASEAN Member States do not attempt to expand ASEAN's membership to external powers outside Southeast Asia. ASEAN fears that Southeast Asian states might ultimately lose the strategic option of institutional balancing, which would be difficult to attain once ASEAN incorporated target states. Therefore, ASEAN Member States instead conducted institutional layering-establishing ASEAN-led institutions-to manage ASEAN-great powers relations, because they can function as either institutional hedging, co-option, or bandwagoning without sacrificing ASEAN's strategic option.
Fourthly, ASEAN developed a weak division of labour among its affiliated institutions to ensure its Member States' security. As many scholars have articulated, ASEAN's emphasis on cooperative security is present in most of the Expansion of EAS's membership and the establishment of ADMM-Plus have served this purpose.
Sixthly, each ASEAN-led institution conducts a different institutional strategy to achieve ASEAN's security objectives, even in the traditional security field. It is evidently difficult for ASEAN to engage in power politics, but ASEAN has used political means to shape the actions of great powers in East Asia through both EAS and ADMM/ADMM-Plus. It is paradoxical that ASEAN has included all regional great powers in the maintenance of regional security and autonomy in Southeast Asia. However, this modus operandi is possible due to the norm of ASEAN Centrality. These fundamental institutional interests have so far been successfully protected, although ASEAN faces difficulty in resolving specific security issues per se, including the South China Sea issue. Indeed, although ADMM's institutional balancing and EAS's institutional hedging have drawn political attention to the South China Sea issue, the maritime situation has yet to become stable. The key challenge for ASEAN will thus be the degree to which ASEAN and ASEAN-led institutions can continue to attract regional great powers, particularly the United States, China, and Japan, and thus achieve stable balance over the South China Sea, in the context of gradual change in the regional distribution of power.
In conclusion, ASEAN cases illustrate political implications for RSIs. It is true that the ASEAN case is unique because there are not many RSIs in East Asia; however, given the ongoing proliferation of RSIs in the world, core groups emerge and create those new institutions, a phenomenon that resembles ASEANtype institution building. Emulating them via ASEAN, this study thus illustrates the potential comparative advantages and political constraints of RSIs in the traditional security field.