ASEAN: still the zone of peace, freedom and neutrality?

ABSTRACT The Association of Southeast Asian Nations’ (ASEAN) pursuit for a Zone of Peace, Freedom and Neutrality (ZOPFAN) first began during the Cold War, at a time of intense superpower rivalry in Southeast Asia. ASEAN reaffirmed the importance of this principle in 2020, amid growing concerns of instability in the Asia-Pacific region as a result of increasing tensions between the United States (US) and China. Through an examination of the ZOPFAN principle, this paper seeks to develop a greater understanding of ASEAN’s ability to respond to periods of geopolitical crisis and Great Power rivalry. It asks whether a ZOPFAN in Southeast Asia has ever been successfully realised, and what is the likelihood of one being achieved in the future. As analysis of recent security challenges will show, ZOPFAN falls short as both a framework for regional security and as an expression of regional autonomy. This raises serious questions about ASEAN’s coherence in the post-Cold War era, and its ability to uphold regional order in light of renewed Great Power security competition.


Introduction
The Association of Southeast Asian Nations (ASEAN) is a regional organisation established during the Cold War to promote cooperation and integration amongst the states of Southeast Asia. Established in 1967, it celebrated its 53 rd anniversary on 8 August 2020. The organisation marked this day by releasing a Foreign Ministers' joint statement on the importance of maintaining peace and stability in Southeast Asia. Highlighting the 'growing uncertainties resulting from the changing geo-political dynamics in the regional and global landscape' the statement expressed concern over the 'detrimental ramifications' of these challenges for the region (ASEAN 2020a(ASEAN , 2020b. In a plea for 'all countries to exercise self-restraint', the statement reiterates ASEAN's commitment to 'maintaining Southeast Asia as a region of peace, security, neutrality and stability' (ASEAN 2020a(ASEAN , 2020b. In doing so, it reaffirms the importance of upholding ASEAN's principles encapsulated within its Treaty of Amity and Cooperation in Southeast Asia (TAC) and Zone of Peace, Freedom and Neutrality (ZOPFAN) (ASEAN 1976;ASEAN 1971 respectively). ASEAN first declared a ZOPFAN in Southeast Asia in 1971 at the height of the Cold War. In a declaration signed by ASEAN's five founding states, 1 the regional states at that time stressed their commitment to 'the principles of respect for the sovereignty and territorial integrity of all states' and 'the right of every state, large or small, to lead its national existence free from outside interference in its internal affairs' (ASEAN 1971). To this end, 'the neutralisation of South East Asia' was viewed as a 'desirable objective' that should be explored and realised (ASEAN 1971).
ASEAN's recent reaffirmation of ZOPFAN is indicative of the increasing instability in the Asia-Pacific region as a result of superpower rivalry between the US and China, and ASEAN's growing fears of becoming embroiled in a potential 'new Cold War' in Asia (Westad 2019). Since the end of the Cold War, the states of ASEAN have pursued largely positive relations with both China and the US, to their own economic and political benefit (Medeiros 2005, 146). Whether this status quo can be maintained in light of deteriorating US-China relations is less clear. As Prime Minister Lee Hsien Loong of Singapore warned in 2018, tensions in the US-China relationship may create circumstances 'where ASEAN will have to choose one or the other', something which he hoped 'does not happen soon' (Muzaffar 2018). To explore these themes in more detail, this paper will examine a number of contemporary crises that have impacted the region as a result of deteriorating US-China relations. Pinpointing a precise date of this downturn in relations is difficult. The paper uses the 2011-2012 timeframe as a starting point. This coincided with the Obama administration's 2011 Asia 'Pivot' foreign policy strategy and the more assertive Chinese foreign policy following Xi Jinping's promotion to President of the People's Republic of China (PRC) (Godbole 2015). Acknowledging China's renewed assertiveness, both the Obama and Trump administrations have sought to counter China's growing regional and international ambitions through foreign policy initiatives such as the Asia 'Pivot' and the Free and Open Indo-Pacific strategy, increased patrols in the South China Sea, and through economic and trade competition.
The paper seeks to explore this complex relationship in more detail through examination of ASEAN's use of the ZOPFAN principle. The paper asks whether a ZOPFAN still exists in Southeast Asia. In doing so it addresses two interrelated questions: has ASEAN's pursuit for a ZOPFAN in Southeast Asia ever been successfully realised? And, what is the likelihood of one being achieved in the future? In doing so, it examines the way in which the changing geopolitical interests and policies of the Great Powers impact the states of Southeast Asia, and how this collection of small regional states align themselves during periods of geopolitical crisis and heightened superpower rivalry. ASEAN's reaffirmation of the ZOPFAN principle in response to deteriorating US-China relations is puzzling considering the Association's limited adherence to the concept to date. Its continued usage has served a purpose, forming part of the Association's strategy at hedging between the Great Powers. As suggested here, use of the concept in this context is increasingly untenable as security competition between the US and China forces ASEAN states to engage in more balancing behaviour. Conceptualised as both a regional security framework and as an expression of regional autonomy, the paper argues that ZOPFAN has ultimately failed to achieve either. ASEAN's unsuccessful attempts at a regional multilateral security dialogue and its inability to prevent external interference in the region make the achievement of a ZOPFAN more a fantasy than a reality. The paper will begin by examining ZOPFAN in more detail. This includes a brief background of the declaration, and an examination of the principle's core aims. The paper will then consider some of the core security challenges to have impacted ASEAN-US-China relations since 2011. Special attention will be given to identifying how these crises have undermined ASEAN's development of a regional security framework and quest for regional autonomy. The paper will conclude with an assessment of the challenges facing ASEAN's pursuit of a ZOPFAN, including the long-term impact for the region of entrenched US-China relations.

Unpacking the ZOPFAN principle
ZOPFAN was born out of a collective desire amongst the states of Southeast Asia for regional autonomy following a protracted period of external interference in the form of Western and Japanese colonialism and US-Soviet Great Power security competition. The implementation of ZOPFAN in 1971 represented a compromise amongst the ASEAN states. Malaysia first proposed a policy of 'neutralisation' in 1970. The proposal had two components: to seek explicit guarantees from the US, Soviet Union and China that they would abstain from involving the region in their security competition; and that regional states would pursue policies of non-interference in each other's internal affairs and avoid inviting external interference into Southeast Asia (Narine 1998, 198). This proposal was not well-received, internationally or regionally. Rather than pursue a policy of disengagement in Southeast Asia, both the US and the Soviet Union actively sought an enhanced presence in the region. Indonesia opposed any proposal that relied on the guarantees of external powers and viewed Malaysia's proposal as a vehicle to facilitate China's influence regionally (Leifer 1989, 56). For Thailand, the Philippines and Singapore, the US was a vital component in their own security strategies. This was something they were unwilling to relinquish at a time of increased instability. The result was a watered-down ZOPFAN, one that 'avoided the legal rigour of the concept of neutralisation and excluded any prerogative role in South-East Asia for major powers' (Leifer 1989, 7). By 1976, ZOPFAN had largely been superseded by the Association's Treaty of Amity and Cooperation. ASEAN's founding peace treaty, the TAC encapsulated a number of core principles that have served to guide member state behaviour. This included formalising a number of objectives designated under ZOPFAN, most notably 'the right of every State to lead its national existence free from external interference' (ASEAN 1976). ZOPFAN was also overshadowed by events in Indochina during the Cold War. The invasion of Cambodia by a Soviet-backed Vietnam in 1978 spread concern throughout the region. Fearing further Vietnamese expansion, ASEAN actively sought security guarantees from the US and China to prevent a Vietnamese fait accompli (Southgate 2019, 71-116). Vietnam's occupation of Cambodia lasted until the end of the Cold War in 1991, allowing ASEAN 'to hold the convenient position that the realisation of ZOPFAN had to await the resolution of the Cambodia conflict' (Acharya 2001, 56). The end of the Cold War injected a renewed sense of hope in ZOPFAN (Alagappa 1991, 271). The principle has since become an embedded part of ASEAN's lexicon. The 2003 Bali Concord II Declaration, the Association's blueprint for future integration, confirmed that political instruments such as ZOPFAN would 'continue to play a pivotal role in the area of confidence building measures, preventive diplomacy and the approaches to conflict resolution' (ASEAN 2003).
This brief history highlights a puzzle central to ZOPFAN. On the one hand, the principle has repeatedly been contravened. ASEAN states prioritised alliances with external Great Powers such as the United States and China as a means of achieving state and regional security during the Cold War. This would suggest that the ASEAN states held little faith in the concept and did not regard it as a means for upholding regional security and stability. At the same time, ASEAN has continued to use ZOPFAN in the post-Cold War period, going so far as to integrate and reaffirm its core principles when it could have been dropped from the Association's lexicon altogether. This suggests that ASEAN perceives the concept as having some utility. It also suggests that the two seemingly opposing positions may not be antithetical. This perspective will be explored in more detail through an examination of the ZOPFAN concept in both the Cold War and post-Cold War period.

ZOPFAN as a regional multilateral security framework
To conceptualise ZOPFAN, this paper adopts an approach utilised by Hanggi (1991). In this view, states are presented with three approaches to national security when threatened by external powers: security through an international alliance, security through regional order and cooperation, and security through non-alignment and neutrality (Hanggi 1991, 1). ZOPFAN is an example of the latter two. It is both a 'prescription for an ideal regional order' (Hanggi 1991, 1) and a 'profession of nonalignment as an ultimate regional goal' (Simon 1982, 3). In examining the former, there is clearly general agreement within the ASEAN security literature that ZOPFAN represents an early attempt at a framework that seeks to promote regional peace and stability in Southeast Asia (Simon 1982;Leifer 1989;Alagappa 1991;Narine 1998). However, deeper analysis shows the limited success of ZOPFAN as a framework for regional security. This has created a weak basis from which ASEAN has expanded its security architecture. Indeed, those factors which limited ZOPFAN's applicability during the Cold War have persisted, undermining ASEAN's more recent attempts at multilateral security. One of the major stumbling blocks for ZOPFAN was that as a framework for state relations it did 'not propose any obligations' on either ASEAN member states or external powers and as such lacked 'operational relevance' (Hanggi 1991, 22, 21). As such, the concept was 'devoid of immediate utility other than to serve as a reference point for and symbol of intra-ASEAN solidarity' (Leifer 1989, 7-8).
For some authors, the latter is an achievement in itself. For Ba (2009, 76), ZOPFAN served to 'reaffirm common principles' within ASEAN, acting as 'a common commitment to one another' during an uncertain period in the region's history. Acharya (2001) adopts a similar approach, viewing ZOPFAN as an early example of ASEAN norm development designed to regulate member state behaviour and enhance regional order. However, evidence suggests that ZOPFAN is more an example of regional state divergence than commonality. ZOPFAN served to highlight the differing threat perceptions amongst the ASEAN states. During the Cold War period, Thailand largely viewed Vietnam as a primary threat following the latter's invasion of Cambodia and Thailand's geographic proximity to the threat. As a front-line state, Thailand was proactive in attempting to secure US and Chinese security guarantees at that time (Southgate 2019). This approach can be contrasted with Indonesia. Believing China responsible for supporting communist elements within its borders, Indonesia viewed China as a primary threat (Southgate 2019, 81). Vietnam was viewed more sympathetically in light of its shared history of external interference. Such differences in threat perception clearly undermined ZOPFAN's utility as a framework for regional security during this time period.
In the post-Cold War, these differing threat perceptions have become even more pronounced. This is in part due to ASEAN enlargement following the end of the Cold War. Between 1995 and 1999, ASEAN expanded to include Vietnam, Laos, Cambodia and Myanmar. These states demonstrate clear differences in their approach to external powers. For example, Cambodia has pursued close relations with China in return for economic and political benefits (Ciorciari 2013). Vietnam, on the other hand, has increasingly sought to strengthen relations with the US as a response to its maritime sovereignty dispute with China in the South China Sea (Heibert, Nguyen, and Poling 2014). These differing perceptions of threat and opportunity underpin a further flaw with ZOPFAN, which is its uneven application vis-a-vis the external powers. Whilst the proposal ostensibly sought to limit all external interference in Southeast Asia during the Cold War, ASEAN's attempts to engage the US and China in a containment strategy of Vietnam indicate that ZOPFAN was actually directed exclusively against the Soviet Union (Simon 1984, 530). This is a point not lost on China, which may view ASEAN's recent reaffirmation of ZOPFAN as an attempt to exclude China regionally. This will be exacerbated by ASEAN's post-Cold War stance towards the two great powers, comprising of a 'generally favourable appraisal of the United States . . . and a more cautious attitude towards China' (Ganesan 2000, 258).
Such divisions and inconsistencies have compromised ASEAN's more recent attempts at multilateral security cooperation. One example of this is the ASEAN Regional Forum (ARF), ASEAN's post-Cold War vehicle for multilateral security dialogue established in 1994. Currently comprising 27 member states, including the US, China and all ASEAN member states, the ARF's aim is to 'foster constructive dialogue and consultation on political and security issues of common interest and concern' (ASEAN 1994). Former Indonesian foreign minister Ali Alatas stated in 1994 that the ARF would provide an opportunity to realise ZOPFAN 'in consultation with friendly countries, taking into account changing circumstances' (Alatas 1994, 13). The ARF's attempt to work with outside powers rather than excluding them represented a departure from the original ZOPFAN blueprint. For Acharya (2001, 172), this erosion of the norm of regional autonomy is an example of ASEAN's prioritisation of the new norm of cooperative security. The ARF's success as a vehicle for cooperative security can be debated, however. Whilst Heller (2005, 123) claims that the ARF is a forum 'that reflects the convergence of strategic interests of both the regional actors and external actors', Narine (1997, 965) highlights that when ARF member state interests diverge ASEAN 'can, at most, create only the appearance of unity'. Differing state interests and threat perceptions, coupled with the Association's inclination to sweep more intractable issues under the rug (Khoo 2004), mean that the ARF ultimately has a limited utility as a framework for regional security. Rather than realise ZOPFAN, the ARF has distorted the principle, making its current application in the contemporary context unclear.

ZOPFAN as an expression of regional autonomy
ASEAN has equally struggled to achieve national security through non-alignment and neutrality (Hanggi 1991, 1). During the Cold War, neutrality was defined by ASEAN as the prohibition of foreign military bases within ASEAN states, abstention from entering into any military alliance or military pact, and prohibition from using, storing or testing nuclear weapons within the region (Hanggi 1991, 26). Neutrality can therefore be understood as an attempt by the ASEAN states to insulate the region from Great Power security competition. For Emmers (2018), the concept of ASEAN neutrality is not static, but evolving. Whilst during the Cold War neutrality was evoked in an attempt to exclude Great Powers from the region, the concept has since been reconceptualised in an attempt to engage the Great Powers in a more inclusive and cooperative way (Emmers 2018, 351). Emmers (2018, 351) goes on to define neutrality according to 'impartiality, to be understood as not taking sides in Great Power dynamics; and autonomy, which refers to an attempt to limit external interference in Southeast Asia's affairs'. Defining neutrality through the notion of autonomy is prevalent elsewhere in the literature. Emmers (2003, 16) has claimed in the past that ASEAN 'in essence . . . registered a call for regional autonomy' through ZOPFAN. Similarly, Ba (1997) states that the signing of ZOPFAN in 1971 'illustrates the transcendent ideal of regional autonomy'.
ASEAN's ability to achieve neutrality in the Southeast Asian region has been complicated by the differing strategic interests of the ASEAN member states. Its ability to act as a unitary actor during the Cold War was continuously challenged. It was most cohesive during the Cambodia conflict, when the threat of Vietnamese aggression and expansion into Southeast Asia helped promote ASEAN cooperation. However, containment of Vietnam was only possible in collaboration with the US and China, thus undermining neutrality. Also, as noted by Emmers (2018, 354), 'the neutrality of a region is likely to depend on its ability to resolve or manage its own potential or actual conflicts'. This view of regional autonomy as a 'regional solution to regional problems' (Acharya 2001, 51) has also been undermined in Southeast Asia, both during the Cold War and in the post-Cold War period. The region has suffered a number of regional crises since 1991, including the Asian Financial Crisis, the humanitarian crisis in East Timor, the South China Sea dispute and the Rohingya refugee crisis, none of which have been resolved regionally. An international peacekeeping force was required to end conflict in East Timor (Cotton 2004). ASEAN have also abdicated any responsibility for the resolution of the Rohingya crisis, necessitating involvement from the United Nations. ASEAN's inability (or unwillingness) to provide regional solutions to regional problems has therefore invited external interference into the region, undermining regional autonomy in the process. Recognising the difficulties in upholding regional autonomy, Emmers (2018, 362) argues that ASEAN shifted from a position of regional autonomy towards a position of impartiality in the post-Cold War period. In this view ASEAN has sought to achieve impartiality by institutionalising regional relations through forums such as the ARF, promoting diplomatic rules of engagement and remaining a central actor in the regional security architecture (Emmers 2018, 362-363). For Emmers (2018, 363) preservation of this impartiality is crucial to prevent being drawn into security competition between China and the US.
The view that ASEAN's institutions and principles have had a positive impact on regional relations and state autonomy is shared by a number of ASEAN scholars. Stubbs (2008, 452) claims that ASEAN's paradigm 'presents an increasingly distinctive and influential option' for regional and global governance. Johnston (1999) goes one step further, arguing that ASEAN's institutions have provided the conditions for the socialisation of external actors, particularly China. This view of ASEAN achieving impartiality through regional multilateral initiatives and centrality has been challenged, however. ASEAN's diplomatic rules of engagement are based upon the 'ASEAN Way', a method of managing state relations through informality, consensus, and non-binding decision making. Whilst ASEAN hoped that its unique organisational structure would provide a non-threatening environment in which to engage external powers over regional challenges, the reality has meant that 'the politics of the lowest common denominator has tended to prevail and difficult problems have been avoided rather than confronted' (Beeson 2016, 10). This preference to shelve intractable disputes has benefited China, which has adopted ASEAN's nonconfrontational style whilst securing its own interests in the region (Jones and Smith 2007, 179). As noted by Jones and Smith (2007, 179), 'conflict avoidance plays into China's hegemonic ambition of returning the region to its precolonial order' whilst 'effectively exclud[ing] the United States'.
Recent events provide further evidence that ASEAN's ability to maintain impartiality has been repeatedly undermined. As the case analysis will show, the South China Sea dispute has divided ASEAN and driven its different members deeper into the arms of the Great Powers. Under the presidency of Rodrigo Duterte, the Philippines has been less vocal in pursuing its claims to sovereignty over maritime territory in favour of deepening engagement with China. In doing so it has unravelled the former Aquino administration's balancing agenda with the United States (De Castro 2016a). Vietnam on the other hand has been incentivised to deepen security ties with the US. ASEAN's struggle to maintain impartiality has increased commensurate with tensions in US-China relations. Whilst ASEAN has attempted to pursue a hedging strategy to balance relations with the great powers (Kuik 2016), this has had mixed success (Ciorciari 2019). As the case of the South China Sea shows, doubts regarding US commitment to defend Southeast Asian maritime security has undermined regional attempts at hedging, forcing claimant states to pursue alternative strategies such as balancing or accommodation towards China (Ciorciari 2019, 526). This became more pronounced as US commitment to the security of the Asia-Pacific region under President Donald Trump waned. ASEAN's 'persistent commitment to hedging' vis-à-vis the great powers in light of increased great power security competition and 'in face of external pressure to take sides' appears increasingly untenable (Tan 2020, 131).
Taken together, this suggests little evidence for a ZOPFAN ever being realised in Southeast Asia. ASEAN state increasing recourse to balance of power politics to secure their own interests, as evident in the South China Sea region, supports the argument that ASEAN views ZOPFAN as a failed and irrelevant concept. This makes its usage as recently as 2020 perplexing. However, continued application of ZOPFAN makes sense when viewed through ASEAN's persistent attempts at hedging since the end of the Cold War. Unlike balancing behaviour, where states are responding to 'clear and present threats' that states must 'resist or accommodate', hedging instead implies the 'cultivation of protective options', that 'do not involve attaining a security commitment, let alone a security guarantee' (Ciorciari and Haacke 2019, 369). Kuik (2016, 504) similarly defines hedging as 'insurance-seeking behaviour' that prepares a 'fallback position' vis-à-vis the competing powers. One of the three main policy elements of any hedging strategy is 'an insistence on not taking sides among competing powers' (Kuik 2016, 504). ASEAN's statements reaffirming ZOPFAN can be viewed as another form of risk management that acts as a protective option positioning ASEAN equidistant between the Great Powers. As hedging makes way for balancing behaviour, utilisation of the concept becomes increasingly unsustainable. What is the likelihood of a ZOPFAN being achieved in the future? The following analysis will consider this question by examining the major challenges that ASEAN has faced as a result of deteriorating US-China relations since 2011. These include the Obama and Trump administrations' changing foreign policy strategies towards the region, the South China Sea dispute and the US-China trade war.

Testing ZOPFAN: contemporary ASEAN-US-China relations
The Obama administration's 'Pivot' to Asia strategy appeared on the surface to be a good example of ASEAN reaping the benefits of engagement with the US without fear of antagonising China. In reality however, the strategy divided ASEAN and raised regional fears of being drawn into a US-led, Chinese encirclement strategy. First articulated by then-Secretary of State Hillary Clinton in an address in Hanoi in 2010, the strategy was formally outlined by President Obama in an address to the Australian Parliament on 17 November 2011. Recognising the 'the vast potential of the Asia Pacific region' (White House 2011), Obama pledged to rebalance US priorities towards Asia by enhancing commitment to regional security, re-engaging with regional organisations (particularly ASEAN), and advancing US-Asia shared prosperity through free trade and the Trans-Pacific Partnership (TPP). The Obama administration's commitment to re-engaging the region was met with a degree of hesitation from within ASEAN. Wary of triggering a negative response from China, the Indonesian foreign minister warned of the potential dangers of a 'vicious cycle of tensions and mistrust' (Bush 2012). Singapore's foreign minister echoed Indonesia's concern, stating that ASEAN wanted to avoid becoming 'caught between the competing interests' of the US and China (Bush 2012). Despite these concerns, evidence shows a gradual increase in US engagement with ASEAN from 2009 onwards.
This began with US accession to ASEAN's TAC in February 2009, a 'symbol of commitment to engagement in Southeast Asia, and to the organization's emphasis on multilateral processes' (Manyin, Garcia, and Morrison 2009). The United States' first resident ambassador to ASEAN was established in September 2010. This was accompanied by an increase in trade between 2012 and 2013, rising from $200 billion to $206.9 billion (Keo 2014). The US also engaged with a number of ASEAN states, including Malaysia, Singapore and Vietnam, through the TPP. President Obama also held an ASEAN Summit at the Sunnylands resort California in 2016 which all ASEAN leaders attended. This was the first time an ASEAN summit was held in the US. Enhanced positive relations with the US was balanced by similar good relations with China. In 2010, the ASEAN-China Free Trade Area (FTA) formally came into effect. This nearly doubled ASEAN-China trade from $192 billion in 2008 to $515 billion by 2018 (Biswas 2018). ASEAN member states were also founding members of the Asian Infrastructure Investment Bank (AIIB), a Chinese-led initiative established in 2016 to counter the TPP. Since establishment, the AIIB committed approximately $670 million of infrastructure loans in ASEAN countries (AIIB 2019). ASEAN's commitment to US and China regional initiatives, in addition to US-China commitment to ASEAN's own multilateral institutions, seemingly supports the assessment by Emmers (2018) of ASEAN seeking to maintain a degree of neutrality in Southeast Asia in accordance with ZOPFAN's core principles. In reality however, this US-China charm offensive has left ASEAN increasingly pulled between two opposing forces. Nowhere is this more pronounced than in the South China Sea, where competing sovereignty claims and increased great power rivalry have stoked disunity and increased external interference in the region.

South China sea dispute: the failure of regional autonomy
One of the Obama administration pledges as part of the Asia 'Pivot' strategy was enhanced commitment to regional security. In Southeast Asia this manifested as support for those ASEAN states engaged in sovereignty disputes with China over territory in the South China Sea. There are a number of overlapping claims to disputed islands in the region. Most notable are the Paracel Islands, claimed by China, Vietnam and Taiwan, and the Spratly Islands, subject to a number of competing claims from China, Malaysia, the Philippines, Taiwan and Vietnam. China claims historic rights to all maritime territory in the region, a claim that it has pursued more assertively over the last decade. Vietnam and the Philippines have been at the forefront of this dispute. Relations between China and Vietnam experienced a downturn in 2007, when China allegedly coerced a number of energy companies to abandon offshore gas development activities initiated by Vietnam (Wikileaks 2007). A standoff between Filipino and Chinese vessels in the Scarborough Shoal in 2012 lasted over two months, triggering anti-Chinese demonstrations in the Philippines (De Castro 2016b). The Obama administration's commitment to regional security came at an opportune time for these states, both of which actively sought US security guarantees in addition to support from regional powers such as India and Australia (Southgate and Khoo 2016).
In 2013 . He reiterated his support in 2015, stating concern that China 'is not necessarily abiding by international norms and rules and is using its sheer size and muscle to force countries into subordinate positions' (The Guardian 2015). As an example of deepening security ties between the two, an Enhanced Defence Cooperation Agreement (EDCA) was signed in 2014 allowing US forces a rotational presence at locations in the Philippines (United States Embassy 2014). The Obama administration also pledged to increase maritime security assistance to the Philippines through the provision of two new naval vessels (Philstar 2015). President Aquino welcomed this greater role for the US in the region, stating 'I think everybody would welcome a balance of power anywhere in the world' (Dancel 2015). Vietnam's relationship with the US also improved significantly at this time. The two implemented a Comprehensive Partnership in 2013, including a commitment of $32.5 million in maritime capacity building, and a Joint Vision Statement in 2015 resulting in a complete lift on the ban of lethal weapon sales to Vietnam. Whilst largely a symbolic gesture, Obama confirmed that this would allow Vietnam 'access to the equipment it needs to defend itself' in the region (White House 2016). Vietnam also looked to strengthen ties beyond the US. It signed a Comprehensive Strategic Partnership with India in 2016, and enhanced bilateral strategic cooperation with Japan, particularly in the area of defence engagement and maritime capacity building (Hiep 2017). These actions taken by the Philippines and Vietnam significantly undermine ZOPFAN. ASEAN's limitations as a conflict resolution actor leave them little choice but to engage external powers in an effort to uphold sovereignty and maintain regional security. A number of ASEAN states disapproved of the Philippines' decision to bring arbitration proceedings against China. These states were particularly disappointed that Manila 'neglected to undertake prior consultation within the grouping' and believed that such an approach 'undermined its efforts towards engaging China multilaterally in striving for a binding Code of Conduct' (Tang 2016). ASEAN's desire to impose regulations on state behaviour in the South China Sea through a legally binding code of conduct has been unsuccessful to date. A non-binding code based on the 'ASEAN Way' principles of restraint and dispute resolution without threat or use of force has been in place since 2002 (ASEAN 2002). However, rather than engage China in a multilateral agreement based on ASEAN norms, the code has been frequently violated. With such divergent positions on the South China Sea, a more binding code has remained elusive. ASEAN has also failed to agree a common stance on the framing of the dispute. Both the Philippines and Vietnam requested that the 2016 ASEAN Foreign Ministers Meeting mention the Arbitral Tribunal ruling in its Joint Communiqué. This was blocked by Cambodia however, which claimed that the dispute should be dealt with on a bilateral basis (Mogato, Martina, and Blanchard 2016). There was a similar outcome at the 2016 Laos Summit, which concluded without an official statement on the dispute. China's ability to utilise its close relations with Cambodia and Laos to undermine ASEAN has further impeded the realisation of a ZOPFAN in the region.

President trump: competition and weakening multilateralism
The election of Donald Trump in 2016 enhanced ASEAN uncertainty at a time of significant regional instability. The new president's determination to abandon all policies put in place by his predecessor, coupled with his 'America First' policy agenda, raised doubts regarding the level of future US commitment towards the region. These doubts appeared realised when President Trump used his first week in office to remove the US from the TPP. US withdrawal was a blow to those ASEAN states that had joined the trade agreement. Senator John McCain believed the withdrawal would send 'a troubling signal of American disengagement in the Asia-Pacific region at a time we can least afford' (South China Morning Post 2017). Withdrawal from the TPP was one of the first indicators of the Trump administration's indifference towards regional multilateral initiatives. His decision to skip the East Asia Summit in November 2017, and the ASEAN summit and Asia Pacific Economic Cooperation (APEC) Summit in November 2018, signalled to many in the region that 'America has essentially abandoned its traditional presence in the Asia Pacific' (Gallu 2018). The Trump administration's preference for bilateral deals with regional states has undermined ASEAN regionalism. As one regional commentator noted, 'without an altogether more wholehearted embrace of the Asia's ASEAN-centred security multilateralism as well as deeper integration within the Asia-Pacific's emerging community-style economic order, the US will find itself relegated to the sidelines' (Gupta 2018).
Under Donald Trump, the US failed to appoint an ambassador to the ASEAN secretariat. This was viewed as a 'big insult' to the group (Jaipragas 2020), further undermining regional trust. As Singaporean Ambassador Tommy Koh stated in 2018, 'if Asia matters to America, why is your leader, President Trump, not here?' (Garekar 2018). This uncertainty has provided an opening for a Chinese charm offensive in the region, causing ASEAN to become even more divided. The election of Rodrigo Duterte as Philippines' president in 2016 proved an opportunity to weaken the US-led counter strategy in the South China Sea. Duterte stated his intention to abandon the Aquino government's approach to competing maritime sovereignty claims with China. When the PCA ruled in favour of the Philippines in the South China Sea arbitration case, Duterte pledged to set aside the ruling in preference for 'open alliances with China' and in favour of 'business, alliances of trade and commerce' (Heydarian 2017, 1). China tempted Duterte with promises of $24 billion in trade and investment in 2016 alone (Heydarian 2017, 13).
Lack of a credible US commitment to the region has undermined the Trump administration's attempt at a more assertive regional foreign policy that seeks to challenge China directly. The 'Free and Open Indo-Pacific Strategy' articulated in 2018 supports regional states 'to protect their sovereignty from coercion by other countries' and in the 'peaceful resolution of territorial and maritime disputes' (US Department of State 2018). The strategy also seeks to promote 'fair and reciprocal trade' (US Department of State 2018), a concept that underpins Donald Trump's protectionist ideals. Conversely, US trade competition with China has negatively impacted ASEAN by threatening regional supply chains whilst also contributing to the deterioration in US-China relations. ASEAN-China economic cooperation has grown significantly as a result, with ASEAN becoming China's largest trade partner in 2020. In an attempt to push back against US protectionism, ASEAN has established a Regional Comprehensive Economic Partnership (RCEP) between ASEAN and five major trading partners (China, Japan, South Korea, India and Australia). First mooted in 2013 and finally established in November 2020, RCEP is the world's largest free trade area. The partnership originally stalled due to tensions between traditional US allies and China, conflict between India and China, and potential-member state fear that the RCEP may become a vehicle for Chinese influence in Southeast Asia. As a result, RCEP became 'a key test for ASEAN's capacity to deliver on its often-cited centrality' (DW News 2019).
In the South China Sea, the US has increased the number of Freedom of Navigation Patrols (FONOPs) from two in 2015 to nine in 2019 (Larter 2020), in addition to sending armed drones and spy planes over the region's waters. It has also stepped-up cooperation with Japan, Australia and India through the Quadrilateral Security Dialogue (Quad), a forum for informal strategic cooperation and dialogue. Despite initial discussion of a 'Quad-plus' to include ASEAN countries, the regional grouping has remained wary of being overshadowed by larger powers and drawn into an anti-China initiative (Saha 2018). Rather than support a ZOPFAN in the region, establishment of the Quad has undermined ASEAN centrality, autonomy and a 'regional solution to regional problems', in addition to existing regional security forums such as the ARF. Nor is the Quad an example of ASEAN neutrality. ASEAN's inability to uphold regional order coupled with uncertainty over US commitment has forced ASEAN member states to seek security guarantees from other regional powers. Vietnam and India have arranged a number of maritime defence engagements in addition to training of Vietnamese maritime personnel and funding for capacity building (Parameswaran 2019). A joint Australia-Vietnam statement in 2018 'underscored the importance of UNCLOS dispute settlement mechanisms and called upon the parties to respect and implement the decisions' of the PCA ruling (Dang 2019). Australian support for UNCLOS and the 2016 Arbitration ruling represents a shift away from a position of neutrality on the South China Sea to one closely aligned to the US and ASEAN claimant states (Thayer 2020). Vietnam has also conducted a number of maritime patrols with Japan, with the two expected to sign an advanced defence equipment deal in 2020 (Ryall 2020).

Conclusion
These recent events cast doubt over a ZOPFAN ever being achieved in Southeast Asia in the future. This is compounded by the long-term effects of the covid-19 pandemic on the region and the change in US leadership following the 2020 presidential election. The economic impact of covid-19 on ASEAN member states has been significant, with disruptions to tourism, businesses and supply chains significantly slowing growth (ASEAN 2020a). ASEAN's initial response lacked unity and cohesion across the grouping. The pandemic stoked tensions between Vietnam and Cambodia, with the former unilaterally closing its borders to prevent spread of the virus. Despite a number of summits and the proposed establishment of a covid-19 response fund, regional commentators noted that a 'unified response from ASEAN remains more in rhetoric than in reality, and in form rather than substance' (Demetriadi 2020). There is also little hope in the region for a reduction in US-China tensions. Whilst an electoral win for Joe Biden in the 2020 US elections has restored some confidence in ASEAN through promises of a more engaged foreign policy strategy, there is less hope that the new president will bring a reduction in Great Power rivalry. Biden stated in 2020 that 'the United States does need to get tough with China', and that 'the most effective way to meet that challenge is to build a united front of US allies and partners to confront China's abusive behaviours' (Biden 2020). This more engaged US foreign policy strategy poses significant obstacles to ASEAN's quest for a ZOPFAN in Southeast Asia.
Examination of ZOPFAN from conception to present day raises deeper concerns over the degree to which ASEAN upholds the concept and whether a ZOPFAN in Southeast Asia has ever been truly achievable. As analysis has shown, ASEAN's attempts to utilise the concept as a fallback position, whilst increasingly seeking security guarantees from external actors, is not sustainable. ASEAN is too easily divided by the Great Powers, and the region has become increasingly polarised. ASEAN's ability to respond effectively to entrenched Great Power security competition whilst pursuing a ZOPFAN is therefore doubtful. Despite reiteration of the ZOPFAN principle, it is clear that the core concepts that underpin the declaration are weak and not adhered to in practice. ASEAN-centric security frameworks have proved unable to address heightened regional conflict, and this has paved the way for new security dialogues that side-line the Association. Increased involvement of regional powers in conflict resolution also undermines ASEAN regional autonomy and the ability of ASEAN to uphold regional order. Does this mean ASEAN is destined to remain powerless in the face of renewed Great Power competition? Arguably, without a united approach underpinned by shared threat perceptions, strategic interests and a common purpose, the ability of ASEAN to agree a strategy vis-à-vis the Great Powers appears increasingly unlikely. Note 1. ASEAN's founding member states consists of Indonesia, Malaysia, the Philippines, Singapore and Thailand.

Disclosure statement
No potential conflict of interest was reported by the author(s).

Notes on contributor
Dr Laura Southgate is a Lecturer in Politics and International Relations at Aston University, UK, where she specialises in Southeast Asian regional security, Southeast Asian regionalism, and international relations theory. Her monograph on ASEAN Resistance to Sovereignty Violation was published by Bristol University Press in 2019.