1 Introduction

On September 15, 2021, leaders of Australia, the United Kingdom, and the United States released a joint statement announcing the creation of an enhanced trilateral security partnership called “AUKUS.” The three countries pledged to “deepen diplomatic, security, and defense cooperation in the Indo-Pacific, including by working with partners to meet the challenges of the twenty-first century” (The White House 2021). The statement highlighted a few modes of cooperation, including deeper integration of security and defense-related science, technology, industrial bases, and supply chain; deeper information and technology sharing; and the enhancement of joint capabilities and interoperability. Initially, the three parties’ areas of cooperation would include cyber capabilities, artificial intelligence, quantum technologies, and undersea capabilities. The most noteworthy was the decision of the US and UK to support Australia’s acquisition of nuclear-powered submarines (SSNs).

The announcement of AUKUS immediately sent shockwaves through many political and policy circles throughout the world. France reacted with fury, because its existing deal with Australia to develop diesel-powered submarines for Canberra would now be cancelled, and Paris had been kept in the dark when the tripartite arrangement was being discussed. China responded with strong criticisms of the new security partnership. A Chinese Foreign Ministry spokesperson charged that the SSNs’ cooperation among the three countries was “extremely irresponsible,” escalating the regional tensions and arms race while threatening international nuclear non-proliferation efforts (Xinhua 2021). Many US allies in Asia, including Japan and South Korea, displayed a positive attitude toward AUKUS. The initial reactions from the EU and its member states were mixed: some states expressed disappointment with the secrecy in the AUKUS negotiations, while others showed continued support for the trans-Atlantic alliance (Marafona 2021). Many discussions on AUKUS have focused on the reactions of the Association of Southeast Asian Nations (ASEAN) and its ten member states.

Such a high level of attention to ASEAN and its member states can be understood from a few perspectives. First, for many years, ASEAN has endeavored to position itself as the central player in regional security multilateralism by convening meetings and helping to set the agenda for various regional multilateral institutions: ASEAN Ministerial Meetings with dialogue partners, ASEAN Regional Forum (ARF), East Asia Summit, and ASEAN Defense Ministers’ Meeting Plus. ASEAN has a very strong interest in sustaining its centrality in regional security multilateralism. In this sense, the fate of AUKUS, an emerging minilateral (involving a small number of nations or parties) security arrangement, may not be totally independent of the responses of ASEAN and its member states. Second, some of the most notable critical views have come from Southeast Asia. Indonesia and Malaysia, for instance, registered significant concerns after the announcement of AUKUS. Other regional states have either provided tacit support to this security pact or remained silent. And it is quite possible that regional views on AUKUS may evolve over time under different circumstances. In this regard, it is important to examine the factors contributing to the diversity of positions among regional states toward AUKUS.

Third, amid the current geostrategic contestations in the Asia-Pacific or Indo-Pacific, the ten-member ASEAN grouping has become strategically important for all major powers. There has been a discernible and strong rivalry among major powers in wooing ASEAN and its member states. The way regional states in Southeast Asia navigate in the ever-growing strategic competition between China and the US-led security coalition, as exemplified by AUKUS, can shape the strategic landscape in the Indo-Pacific. Finally, through the implementation of AUKUS, the operations of Australia’s nuclear-propelled submarines may mainly take place in Southeast Asia, particularly in the South China Sea. Thus, the way regional states respond will affect AUKUS’s capability to deter or constrain China in the region.

This paper attempts to analyze how and why regional states in Southeast Asia have responded to AUKUS in specific ways. Despite the divergence in regional states’ views, we can perhaps draw this conclusion: 1 year after the pronouncement of AUKUS, ASEAN as a collective entity has already cautiously accepted AUKUS as a new reality. Facing ASEAN now are two highly challenging tasks: first, how to carefully address the intensifying US–China rivalry; second, how to deal with the threats to its unity and centrality posed by this new tripartite security arrangement. Also, it is quite clear from ASEAN’s grudging embrace of AUKUS that this minilateral security pact will instigate many new dynamics in Indo-Pacific regional security. Certainly, it will not be easy for AUKUS to achieve the balance of power or the deterrence effect that its initiators intended any time soon. However, many signs suggest that AUKUS may continue to expand its influence through the building of partnerships and the promotion of practical cooperation that may involve many regional states, including AEAN member states, in the future. Amid the US–China strategic rivalry, regional strategic alignments may become even more divisive and competitive.

2 ASEAN countries’ different responses to and cautious acceptance of AUKUS

The most salient development in the Indo-Pacific region in recent years has been the intensification of strategic realignments due to the reinvigoration of the quadrilateral security dialogue (QUAD) between the United States, Japan, Australia, and India. The significant enhancement of cooperation among the QUAD members since 2017 has been aimed at balancing China’s influence in the Indo-Pacific region. This can be seen in the increased intensity of military exercises, sharing of technological standards (such as 5G), assistance programs for COVID-19, and climate change mitigation.

Compared to QUAD, AUKUS is a much more consequential development in regional security relations. It has been described as the “tectonic plates of geopolitics shifting,” comparable to events such as Suez in 1956, Nixon’s China visit in 1972, and the fall of the Berlin wall in 1989 (The Economist 2021). The emergence of AUKUS is widely interpreted as a dramatic escalation of US strategic commitment to deal with the challenges posed by China’s rise, particularly in the Indo-Pacific region. In the words of one analyst, AUKUS “marks a shift in US global strategy, redistributing its forces by empowering its allies to strengthen military capabilities around the Indo-Pacific” (Cheng 2022). This strategic move symbolizes a major transformation in US alliance policy in Asia. In this context, it becomes important to understand ASEAN and its member states’ responses to AUKUS.

ASEAN countries’ responses can be generally divided into three groups. First, Malaysia and Indonesia have openly demonstrated concerns and anxieties over the risks of nuclear proliferation and arms race but have not explicitly opposed AUKUS. Second, Thailand, Cambodia, Laos, Brunei, and Myanmar have decided to refrain from making open and unambiguous comments. Their low-profile posture can be interpreted as tacit acceptance of AUKUS. Third, Philippines, Vietnam, and Singapore have been ostensibly supportive of the new security pact. At the ASEAN level, there has been no common position and very limited joint diplomatic action in response to AUKUS. One year after the emergence of AUKUS, it is now perhaps safe to conclude that ASEAN and most ASEAN member states have cautiously accepted AUKUS.

Almost immediately after the announcement of AUKUS, the Indonesian Ministry of Foreign Affairs issued a five-point statement. According to the policy statement, Indonesia “takes note cautiously” of the Australian Government’s decision to acquire SSNs. “[D]eeply concerned over the continuing arms race and power projection in the region,” Indonesia “stresses the importance of Australia’s commitment to continue meeting all of its nuclear non-proliferation obligations” (Ministry of Foreign Affairs of the Republic of Indonesia 2021). Clearly, Jakarta was displeased with the prospect of Australia possessing SSNs and worried about the potential negative impact of AUKUS on regional stability and nuclear non-proliferation.

Interestingly, Indonesia’s statement did not mention AUKUS by name, and its views were “articulated in a rather tepid undertone” (Jaknanihan 2021). Moreover, Jakarta’s statement only emphasized concern but not hostility toward Canberra. It is also interesting to note that the Indonesian Ministry of Defense has been far less vocal than the Ministry of Foreign Affairs. At the ASEAN-Australia Summit in late October 2021, Indonesian President Joko Widodo expressed his worries to the then-Australian leader Scott Morrison about AUKUS, particularly the possibility of increased rivalry in the region (Iwamoto 2021). Meanwhile, many Indonesian officials and policy analysts complained about the fact that Indonesia and ASEAN had not been consulted before the AUKUS announcement and expressed serious concerns about the negative impacts on ASEAN’s capacity for managing regional security. In a nutshell, Indonesia’s position toward AUKUS reflects its displeasure, elements of concern, neutrality, and “deeper fear of being sidelined if similar moves unfold in the future” (Jaknanihan 2021). Notwithstanding these concerns, it should also be noted that there is a minority view in the country that Indonesia and ASEAN should instead welcome AUKUS (Supriyanto 2021).

Stronger negativity against AUKUS has come from Malaysia. Malaysian Prime Minister Ismail Sabri Yaakob stated that AUKUS could be a “catalyst for a nuclear arms race in the Indo-Pacific region” (The Sydney Morning Herald 2021). He made it clear that his government rejects any alliances that share nuclear weapons or related technology. In a media interview later, the Malaysian leader said that “we are worried that some other major economies will take advantage of AUKUS….For example, if China wants to help North Korea purchase nuclear-powered submarines, we can’t say no because AUKUS has set a precedent” (Associated Press 2022). On September 19, 2021, the Malaysian Ministry of Foreign Affairs issued a press release, which was much longer than the Indonesian five-point statement and also explicitly mentioned AUKUS. The press release included the Malaysian Foreign Minister’s “concerns that the establishment of AUKUS could lead to the escalation of arms race in the region,” adding that “it could also potentially spark tension among the world superpowers, and aggravate aggression between them in the region, particularly in the South China Sea” (The Malaysian Ministry of Foreign Affairs 2021). Malaysian Defense Minister Hishammuddin Hussein also gave a negative response to AUKUS, and even stated that Malaysia might consider consulting China on the AUKUS issue (South China Morning Post 2021). His remark on consultation with China invited criticism from other political leaders in Malaysia. It is worth noting that a senior Malaysian official has explicitly informed Australia that a special approval must be obtained from the Malaysian government before Australian SSNs can enter Malaysian waters, dock at Malaysian ports, or conduct joint-military exercises (Tan et al. 2021).

As a treaty ally of the United States and a close strategic partner of China, Thailand felt that it was caught in-between by the announcement of AUKUS. Fearing being perceived as taking sides, Thai leaders and government agencies have not issued any formal statement regarding AUKUS. Another factor for Thailand’s circumspection was its leaders’ preoccupation with domestic affairs. Notwithstanding acquiescence, Thai Prime Minister Prayut Chan-o-Cha did emphasize in his UN speech that his country would support the Treaty on the Prohibition of Nuclear Weapons and the Nuclear Non-Proliferation Treaty (NPT). According to analysts, this part of his speech suggests that Thailand has some reservations about AUKUS (Choong and Storey 2021). The Thai government’s caution is shared by prominent analysts in the country. For instance, Kavi posits that “Bangkok views the latest US move as a destabilizing factor, as it will put every nation in the region on high alert” (Chongkittavorn 2021). A few other regional states shared Thailand’s elusive posture. Cambodian Foreign Minister Prak Sokhonn expressed his government’s hope that AUKUS would “not trigger unnecessary and ‘unhealthy’ competition and tension in the region” (Niseiy 2021). A senior Bruneian official underscored ASEAN’s central role in regional security arrangement and noted ASEAN’s worry that “the pact may provoke further tension between western powers and China” (Bandial 2021). Both Myanmar and the Laos have abstained from making any open comments on AUKUS. It is very unlikely that these countries will question AUKUS in any meaningful manner in the future. They will treat the existence and development of AUKUS as a reality in regional security.

Singapore’s response to AUKUS was generally positive. During a telephone conversation with the Australian leader on September 16, 2021, Prime Minister Lee expressed his hope that “AUKUS would contribute constructively to the peace and stability of the region and complement the regional architecture” (Ministry of Foreign Affairs (Singapore) 2021a). In his response to a question from Parliament on the AUKUS issue in October 2021, Minister for Foreign Affairs Vivian Balakrishnan repeated Lee’s position, commented positively on the relations between the AUKUS countries, Singapore, and ASEAN, as well as on the Five Power Defense Agreement. Besides stating that regional architecture should be open and inclusive, he also commented positively on relations with China and emphasized the importance of cooperation and constructive engagement among all stakeholders in the region (Ministry of Foreign Affairs (Singapore) 2021b).

Vietnam viewed AUKUS through an even more positive lens. According to Vietnamese Foreign Ministry spokesperson, AUKUS will be a positive force for regional stability: “All countries strive for the same goal of peace, stability, cooperation and development in the region and the world over.” Regarding Australia’s plan to acquire nuclear-propelled submarines, Vietnam’s response demonstrated a sense of mild, almost irrelevant caution: “The nuclear energy must be developed and used for peaceful purposes and serve socio-economic development, ensuring safety for humans and the environment” (Anh 2021).

In the Philippines, former President Duterte appeared to be the only main political leader in the country who displayed some reservations about AUKUS. Following the AUKUS announcement, Presidential Spokesperson Harry Roque said that Duterte was worried that the pact could trigger a “nuclear arms race” (Gita-Carlos 2021). Duterte also stated that AUKUS should not complicate the working methods of cooperation between ASEAN and the United States during his virtual appearance at the 9th ASEAN-United States Summit, adding that all stakeholders should exercise self-restraint to avoid unintended consequences in the South China Sea (Office of the Press Secretary (Philippines) 2021). However, the senior foreign and security policy officials in the Philippines have provided clear and strong support to AUKUS. Defense Secretary Delfin Lorenzana told his Australian counterpart that Australia had the right to improve its submarine defense capability. Lorenzana further noted that “as a country strategically situated in Southeast Asia, the Philippines is also building its own capability to protect its territories” (Nepomuceno 2021). In an official statement, Secretary of Foreign Affairs Teodoro L. Locsin Jr. explicitly said that “The Philippines welcomes Australia’s decision to establish an enhanced trilateral security partnership with the United States primarily and the United Kingdom,” stressing the point that the increased military strength of such a security pact would help to address the balance of power in the region and to cope with security challenges in the South China Sea (National Government Portal Philippines 2021). With the inauguration of Ferdinand Marcos Jr. as the Philippines’ new president in June 2022, Manila’s receptive position on AUKUS has remained.

In the months after the announcement of AUKUS, a few attempts were made to push for collective discussion among ASEAN member states and to come up with a group position. However, these efforts have been unsuccessful. Malaysian Senior Minister (Security) Datuk Seri Hishammuddin Hussein noted that AUKUS must be collectively addressed by the ten members of ASEAN. He stated that he would contact his Cambodian and Filipino counterparts on the issue and encourage group discussion on AUKUS at the ASEAN Defense Ministers’ Meeting (ADMM) retreat in November 2021 (Tan et al. 2021). In October 2021, the foreign ministers of Malaysia and Indonesia held bilateral talks to discuss the AUKUS issue. After the meeting, the two ministers reiterated the same concerns they had expressed immediately after the AUKUS announcement (Strangio 2021a).

At the ASEAN Summit in late October 2021, almost all leaders from the regional grouping emphasized the importance of maintaining ASEAN centrality and getting other major powers to respect the ASEAN Outlook on the Indo-Pacific. At the end of the Summit, there was no mentioning of AUKUS in the ASEAN Chairman’s Statement. According to Malaysia Prime Minister Ismail Sabri Yaakob, “Malaysia finds it regrettable that there was a lack of unity on issues that could impact regional peace, stability and security, namely AUKUS and [the Southeast Asia Nuclear Weapon-Free Zone] treaty” and “that ASEAN was unable to come up with a statement on the establishment of the trilateral security arrangement” (Iwamoto 2021).

3 Explaining ASEAN’s cautious acceptance of and varied responses to AUKUS

Clearly, ASEAN and its member states have cautiously accepted the existence of AUKUS as a new reality. It would then be necessary to understand the rationales behind ASEAN’s grievances, concerns, default acceptance, and refusal to offer explicit opposition or support. Various factors, including perceived challenges to ASEAN’s centrality, the strategic nature of AUKUS, and most ASEAN countries’ shared views about China, have led to ASEAN’s mixed reactions to AUKUS.

3.1 Challenges to ASEAN centrality

In the post-Cold War era, ASEAN took on the role of steering various regional institutions to help mitigate the competition between extra-regional powers in the region. This regional grouping assumed this role when no major power was interested in taking the lead in forging security cooperation. In the process, ASEAN leaders decided to promote their own norms and aspirations in their interactions and relations with other major powers, as seen in the Treaty of Amity and Cooperation in Southeast Asia, the Zone of Peace, Freedom and Neutrality (ZOPFAN), and the Southeast Asia Nuclear Weapon-Free Zone (SEANWFZ).

In the past few years, however, concerns in Southeast Asian countries about the growing challenges for ASEAN’s central role in managing regional security multilateralism have ostensibly grown. The growth of such concerns has to do with the dramatic increase in US–China strategic rivalry and the emergence of various minilateral arrangements, such as the QUAD. ASEAN leaders have been frustrated with being unable to help mediate major-power competition and set the agenda at various regional institutions such as the East Asian Summit. There have been discernible signs of disunity among ASEAN countries on some regional issues as well, for instance the South China Sea disputes. The emergence of AUKUS poses another significant, perhaps even greater, challenge to ASEAN’s position in the driver’s seat of regional multilateralism.

When Australian Prime Minister Scott Morrison issued the statement on AUKUS, ASEAN was mentioned only once in an insignificant manner: the trilateral agreement “will complement Australia’s network of strategic partnerships, including with our ASEAN friends” (Bisley 2022). This suggests that AUKUS serves as a strong reminder that ASEAN faces daunting obstacles in its effort to address regional strategic challenges. It also signals to the rest of the world that significant developments in regional security architecture could happen without ASEAN being consulted. For example, the ASEAN Regional Forum (ARF), which is designed as a platform for all relevant parties to engage in open dialogue on regional security issues, was dealt a big blow by AUKUS, because two important participants, the US and Australia, moved to build the trilateral security pact without giving any prior notice to ASEAN or ARF partners (Ankersen 2022). Indonesia, in particular, feels very uncomfortable for being “made publicly redundant” (Laksmana 2021).

In the words of regional observers, “AUKUS is a wake-up call to ASEAN that it needs to be more proactive on security issues and cannot take its centrality for granted” (Choong and Storey 2021). Former Indonesian Foreign Minister Marty Natalegawa noted that AUKUS served as a reminder for ASEAN of “the cost of its dithering and indecision on the complex and fast-evolving geopolitical environment” (Thakur 2021). A view that is widely shared in the region is that if ASEAN cannot function as a “buffer and broker” among the major powers, there would be a significant rise in regional geopolitical tensions and ASEAN’s driver’s seat in the Indo-Pacific would be sidelined “as major Western powers expand their presence and maneuvers in the region” (Pongsudhirak 2021).

Specifically, these challenges could manifest along three dimensions. First, minilateral security arrangements such as AUKUS denote the adoption of hard balancing by the United States and its regional partners and their lack of interest in relying on ASEAN’s normative influence when dealing with China. Second, because of its small and nimble membership, AUKUS aims to be a lot more effective than ASEAN institutions “in delivering tangible results and effective responses to regional security challenges.” Third, AUKUS may “accentuate the pre-existing strategic incoherence within ASEAN in the face of Great Power competition” (Ha 2022). AUKUS also poses a challenge to the ASEAN Way, which places emphasis on consensus-building, dialogues, peaceful means to solve problems, inclusiveness, and informality in diplomatic and political processes (Ronodipuro 2021). The erosion of ASEAN centrality and normative power may produce a vicious cycle for this regional grouping. For a long time, all member states have been interested in supporting ASEAN, primarily because it could help each individual state exercise a much bigger diplomatic and political role. The weakening of ASEAN’s functionality would exacerbate the already existing differences among member states, leading to further challenges to its regional centrality. The discernible challenges to ASEAN unity and centrality help explain why ASEAN countries have been cautious and reluctant to provide open support to AUKUS.

3.2 AUKUS’ balance of hard power versus ASEAN’s hedging

ASEAN countries’ unwillingness to openly support AUKUS is also related to the strategic nature of AUKUS. AUKUS was established to pursue a balance of hard power and potentially military confrontations with China. Such a strategic move is incompatible with ASEAN countries’ hedging strategy toward China and US–China rivalry. At the same time, the strategic misgivings that some regional states harbor in their relations with China help explain why they do not intentionally oppose AUKUS either.

Many pundits have argued that the AUKUS pact is intended to work in symbiosis with the QUAD and the Build Back Better World (B3W) and the Blue Dot Network (BDN) to counterbalance Beijing’s growing influence in the Indo-Pacific region (Reisinezhad 2021). Moreover, “AUKUS explicitly signaled its intent to deter China militarily” (Chong 2021). And apparently, Washington has succeeded in enmeshing its allies, including the United Kingdom and Australia, for this strategic purpose for decades to come. This strategic interpretation is based on a few observations. For instance, many analysts highlight the fact that the United States only transferred the nuclear-propulsion submarine technology to the United Kingdom, one of the five nuclear weapons states, at the height of the Cold War. Equipping a non-nuclear weapons state, albeit a close ally, with this technology suggests that Washington may be prepared to engage in a Cold War with China, an option that US leaders have so far attempted to openly deny (Roggeveen 2021). In the words of one analyst, “The larger significance of this is that the United States is doubling down on its allies, and its allies are doubling down on the United States” (The Economist 2021).

Also, on the part of Australia, it made a bold decision to ditch the existing deal with the French Naval Group, a company with the French state as the majority stakeholder. This decision reflected Canberra’s strong interest in acquiring a stealthier and more capable fleet of submarines that have a much longer range than the diesel–electric ones. Australia’s defense capability will be significantly boosted by the addition of the eight nuclear-powered submarines given the fact that only six countries in the world operate such SSNs and they all have a civilian nuclear industry and possess nuclear weapons. Thus, this decision fundamentally reflected Australia’s strategic resolve to join the US encirclement strategy against China in the Indo-Pacific region.

Moreover, beyond submarines, AUKUS has proposed a very ambitious and radical plan to compete with China in the technology sector by pooling resources and integrating technologies and supply chains among the three countries. Under AUKUS, the three partners are supposed to cooperate closely on some cutting-edge technologies, including artificial intelligence, quantum computing, and cyber technology, which will be tremendously relevant for upgrading military power. The United States has chosen the UK and Australia for this comprehensive strategy to counter China largely because all three countries are members of the Five Eyes intelligence alliance. In the assessment of Washington, the UK and Australia, unlike the other two Five Eye members Canada and New Zealand, are more strongly committed to the Free and Open Indo-Pacific vision. Decades of cooperation, including collecting and sharing intelligence data under the Five Eyes framework and joint-military operations in the Iraq and Afghanistan wars, deepened the trust between the three countries. Otherwise, it would be unthinkable that Washington would be prepared to share such sensitive technologies with ally countries (Tarapore 2021).

Considering AUKUS’s strategic intention to pursue a balance of hard power and potentially provoke a Cold War against China, it is almost impossible for most ASEAN countries to openly support it. In the past decades, ASEAN countries have practiced a socialization or omni-enmeshment strategy with China, trying to integrate China into the regional multilateral institutions, build economic interdependence, and pursue hedging strategies of various types, hoping to both engage with China to maximize their national interests and balance China to prevent the emergence of a Sino-centric regional order. Apparently, the rationales behind the hedging strategies of almost all regional countries are not aligned with the strategic logic underpinning AUKUS.

Such strategic differences are significant. Most ASEAN countries understand the political, economic, and security challenges associated with the rise of China, but they do not regard China as an extant threat. Socio-political elites in Southeast Asia also realize that China has already emerged as the most influential strategic and economic player in the region, as seen in the annual survey reports released by ISEAS-Ishak Institute. The State of Southeast Asia 2021 report suggests that 49.8% of respondents believe China has become the most influential strategic and political power in the region, and this figure rose to 54.4% in the 2022 survey. The two surveys also show that China is now the most influential economic power in the region, with 75.9% and 76.7% of respondents acknowledging this in 2021 and 2022, respectively (Seah et al. 2021, 2022). Clearly, strategically confronting China or engaging with China in an adversarial relationship is not in the interest of ASEAN countries.

In many respects, the United States is important for ASEAN countries, but regional states highly value the strategic status of ASEAN as an institution. This is not the case for Australia, because Australia places much more of a premium on the United States, than on ASEAN or ASEAN-led regional multilateralism in its foreign policy making (Laksmana 2021). ASEAN leaders understand that AUKUS may not threaten any regional country directly, but it will inevitably generate strategic responses from China and significantly escalate US–China rivalry in the region. Such intensified military contentions will only increase insecurity for many Southeast Asian countries (Darmawan 2021). A retired senior diplomat in Indonesia explained this view well:

ASEAN welcomes open competition between the big powers within the region, of the right kind (namely competition in peace and for progress). ASEAN countries stand to benefit from positive competition among China, the United States and Japan, for example, for trade, investment, and educational opportunities. What ASEAN does not want is the kind of bitter zero-sum rivalry that would create tension, mistrust and division and thus (once again) pull the region apart (Djalal 2021).

3.3 ASEAN countries’ strategic misgivings toward China

At the same time, Southeast Asia is keen to rely on the United States and its allies to balance China’s expanding influence in the region and beyond. The ISEAS 2021 and 2022 surveys show that 86.5% and 76.4% of respondents in the two respective years are concerned about China’s growing political and strategic influence. The two surveys also indicate that 68% and 64.4% of them in the two respective years have concerns about China’s economic influence in the region. Regarding regional states’ trust toward major powers, respondents in both the 2021 and 2022 surveys ranked China significantly behind Japan, US, and EU. In the 2022 survey, as many as 58.5% of respondents agreed or strongly agreed that the strengthening of the QUAD, including through practical cooperation, will be constructive for the region, while 36.4% of them believe that AUKUS will help balance China’s growing military power (Seah et al. 2021, 2022).These concerns and distrust toward China can explain why ASEAN does not explicitly oppose AUKUS, why some ASEAN countries are more supportive of AUKUS, and why even the negativities from Malaysia and Indonesia have been moderate.

The supportive views on AUKUS coming from Hanoi and Manila, for instance, can be understood through this lens, as these two countries have complex territorial and maritime disputes with China in the South China Sea. It is perhaps only natural that the foreign policy and security communities in the two countries would be happy to see the balancing and even deterrence effects of AUKUS against China in the South China Sea region. Likewise, there is a notable view in Indonesia that AUKUS, despite some of the negative impacts on Indonesia and regional security, may not be entirely bad. Some Indonesian analysts argue that under the “free and active” foreign policy guidelines, Jakarta’s strategic autonomy and priority should not rely solely on ASEAN, because ASEAN member states are no longer showing the same level of solidarity on many key regional issues. Privately, some Indonesian security officials might feel relieved that ASEAN countries could leverage AUKUS against China. At least one Indonesian Parliament member opined that the Indonesian government should back AUKUS mainly because of the activities of China’s naval and coast guard vessels in the waters near Natuna (Jaknanihan 2021).

Moreover, ASEAN countries would not oppose AUKUS, because their relations with the three countries are very important. For instance, Indonesia has a strong interest in upgrading its defense ties with Australia, as demonstrated at the seventh 2 + 2 meeting between the two countries in early September 2021. Moreover, the realization of Indonesia’s military modernization blueprint will need technological assistance from the AUKUS partners. The license to manufacture two Arrowhead-140 frigates signed by Indonesian Defense Minister Prabowo and UK Secretary of State for Defense Ben Wallace on September 17, 2021 is a good example in this regard. In line with these considerations, some Indonesian analysts have proposed that “future ASEAN strategy should begin to recognize AUKUS, the Quad, and other similar arrangements as useful assets that complement ASEAN institutions and centrality” (Jaknanihan 2021).

It is difficult to say whether bilateral ties between ASEAN and Australia have been substantively affected. On the contrary, the relationship appears to have remained on a positive track. In late October 2021, at the first ASEAN-Australia Summit, the two sides decided to elevate their relations to a Comprehensive Strategic Partnership that is meaningful, substantive, and mutually beneficial. According to the Chairman’s Statement after the summit, leaders from these countries also “discussed the recent AUKUS announcement… including Australia’s decision to acquire nuclear-powered submarines, during which views were expressed on its implications for the region.” In addition, ASEAN countries “welcomed Australia’s continued support and reaffirmation for ASEAN Centrality and commitment to promote regional peace, stability and security, in accordance with the TAC as well as the steadfast commitment to meet all its obligations as a non-nuclear weapons state under the Nuclear Non-Proliferation Treaty” (Chairman’s Statement of the 1st ASEAN-Australia Summit 2021).

4 Potential geostrategic impacts of AUKUS on Indo-Pacific security

At present, AUKUS appears to be at a very preliminary stage. The policy community is aware that the agreement is “a big Australian bet on the future of the United States, at a more uncertain time in American politics than at almost any point in the history of the alliance” (Gyngell 2021). The uncertain geostrategic impacts on Australia itself may also make the implementation of AUKUS not as smooth as many policymakers hope. Despite that, the deal on the SSNs may indeed generate some dynamics akin to a regional arms race. It is also unclear how the specifics of cooperation in so many areas between the three powers will unfold. However, it is possible that with the passage of time and the appeal of various proposals of partnership with other parties, more and more states may realize the usefulness of this security pact.

4.1 Challenges for Australia’s strategic and security interests

One way to gauge the long-term implications of AUKUS for the Indo-Pacific region is to look at Australia’s strategic resolve in leveraging AUKUS to deal with China’s rise. AUKUS, despite many positive assessments of its utility as a strategic tool, has not been without critics either inside Australia or in other parts of the world. In fact, skepticism and critical views have intensified. First, AUKUS represents US strategic intent to work with its allies to strengthen its military balance against China. Through AUKUS, Australia has become a strong participant in the US strategic game, even though many US Asian allies and partners have been vacillating between balancing and hedging (Kapur 2021). At present, the global multilateral economic system is facing many challenges. Given the economic interdependence between Australia and China, Australia’s open economy may become even more vulnerable to major-power geopolitics. According to one analyst, “security arrangements like the recent Australia–UK–US (AUKUS) Pact will become an economic straitjacket” (Westland 2021).

Some analysts argue that AUKUS may not be directly relevant to Australia’s defense of its own territory. According to these strategic skeptics, Australia’s own security and defense could be best served by having a fleet of smaller conventional submarines, given the various geographic advantages that Australia enjoys. The following two questions remain unanswered or only partially answered: “Why does Australia need these long-range submarines to operate in the South and East China Seas?” and “What strategic goals can Australia achieve by leveraging those submarines?” It is also doubtful whether Australia, as a relatively smaller power, has adequate material strength to strive for a three-ocean naval force. If Australia’s intention is to use this new naval capability to help shape a rules-based order in the region, there are many other means to achieve such an objective. Other observers have argued that Australia’s acquisition of the fleet of nuclear-power submarines may take a long time, perhaps nearly 2 decades. By then, it would be too late for Canberra to play a significant naval role in a Taiwan contingency.

Australia does not have a domestic civilian nuclear industry; therefore, technical questions have been raised about the country’s capability to provide all the technical personnel that would be needed to construct and operate the new SSNs. Very likely, Australia would need to outsource its operation of SSNs to the US Navy at the expense of its sovereignty (Wyeth 2021). Moreover, it is argued that by the time Australia obtains the SSNs, China’s anti-submarine capability may have advanced to the extent that the Australian boats could be vulnerable in the waters near China’s coast. Also, operationally speaking, during normal times, the Australian SSNs may very well need the air cover of the US aircraft carrier task force. During war time between the United States and China, the Australian Defense Force, including its SSNs, is likely to be integrated into the US military force. Inevitably, Australia becomes a party in a war with China. If Australia gets involved in a military confrontation between two major powers with nuclear weapons, its national security will be placed at a high risk. In this sense, cancelling the French submarine project and opting for the SSNs would be akin to going “from the frying pan into the fire” (Palazzo 2021).

These strategic concerns for Australia and the technical challenges may essentially suggest that the deterrence AUKUS provides against China may be constrained to some extent, even if Washington continues to show a strong commitment to this security arrangement. Significant improvement in China–Australia relations, if this happens soon, may also help to offset Canberra’s strategic incentives in counterbalancing China while increasing risks and opportunity costs for Australia.

4.2 Concerns about nuclear proliferation and regional insecurity

Soon to be the first non-nuclear weapons state to develop SSNs, Australia will need to exploit a loophole in the NPT that allows a non-nuclear weapons state to receive nuclear material for military use, but under the condition that such material is not used for explosive devices. Four countries currently use highly enriched uranium (HEU) naval reactors for their nuclear-powered submarines, including the US, UK, Russia, and India. It is highly likely that Australia’s SSNs will also adopt HEU. According to a professional analysis, “Most existing HEU naval nuclear reactors use weapons-grade uranium (enriched to over 90 per cent) or uranium enriched to at least 20 per cent U-235. For context, a typical civilian nuclear-power reactor uses about 3.5 per cent enriched uranium” (Moloney 2021). Theoretically, a country that uses weapons-grade uranium in its SSNs could potentially develop nuclear weapons at the same time. Thus, there emerges a challenge for Australia to seriously address the concerns that have been expressed by some countries regarding the risks of nuclear proliferation. In this context, the ball is in Australia’s court to create and comply with additional stronger measures for the production, use, and disposal of HEU as required by the IAEA and NPT regimes.

What happens next is that Australia, as a non-nuclear weapons state, will need to make a special arrangement for inspection with the International Atomic Energy Agency (IAEA), a watchdog preventing any non-nuclear weapons states from using nuclear material to build weapons (Wyeth 2021). In September 2022, the IAEA reported that it was satisfied with the technical information that the AUKUS partners have shared. China registered strong protest with the IAEA, stating that it would be wrong and dangerous to “endorse the nuclear proliferation acts of these three countries” (Liu 2022). Deviating slightly from China’s argument, ASEAN countries are not asserting that they are not confident in Australia’s own non-proliferation commitment. ASEAN’s anxiety eased to some extent after the Australian government made strenuous attempts to convince regional states that Australia would not seek nuclear weapons and would remain consistent with its commitments to nuclear non-proliferation (Strangio 2021b). However, ASEAN leaders remain concerned about the spillover effects of Australia’s SSNs. Indonesia, for instance, reportedly made the argument that the transfer of nuclear material for non-explosive military purposes would still constitute a violation of the spirit and objectives found in the NPT regime (Wyeth 2021). Indonesia also “raised its concern that sharing of nuclear technology to power submarines could heighten the risk of new weapons of mass destruction.” Other ASEAN countries, including Vietnam and Thailand, also share these concerns (Tyler 2022). It has been pointed out that some nuclear-ambitious countries may exploit the possible loopholes that may come out of the IAEA’s oversight of Australia’s use of HEU.

Such a scenario is unlikely to happen in Southeast Asia. Financial constraints make it almost impossible for AUKUS to coax Southeast Asian countries into acquiring nuclear-propelled submarines. In response to AUKUS, some ASEAN countries may be tempted to double down on conventional armaments, such as various types of anti-submarine systems: “surface ships optimised for such missions, maritime patrol and reconnaissance aircraft, and seabed hydrophone sensors” (Koh 2021). The Royal Thai Navy has already reportedly expressed interest in using AUKUS as a justification for its plan to purchase two more diesel-powered Yuan class submarines from China (Barua 2021). And China and India, among other powers in the Indo-Pacific region, may be interested in expanding their already existing fleet of nuclear submarines. South Korea and Japan may become more serious in exploring the option of possessing SSNs (Koh 2021). Although it may not be likely that China will attempt to build new alliances in the foreseeable future, Beijing may be tempted to engage in AUKUS-type defense relations with some countries in the region, because AUKUS has removed constraints for China to do so (The Australian Financial Review 2021). North Korea has strongly criticized AUKUS, and the whole AUKUS issue may make it more difficult to achieve any progress in talks regarding North Korea’s nuclear and missiles programs (Economist Intelligence Unit 2021).

Putting aside nuclear proliferation issues, regional states may be concerned about nuclear safety issues emanating from SSNs. The collision of the US nuclear submarine Connecticut and an undersea object in the South China Sea in early October 2021 has been viewed as a warning that too many SSNs in the region may be a potential source of radioactive leakage that may be harmful to the region’s marine ecosystem (Ronodipuro 2021).

4.3 Possible expansion of AUKUS partnerships

Apparently, Washington is already interested in further expanding AUKUS. In a recent interview with the Lowy Institute, Kurt Campbell, the White House’s Indo-Pacific coordinator, referred to AUKUS prospectively as “an open architecture … which other countries might join in time.” AUKUS, according to Campbell, will serve as a platform through which the US seeks to work with “like-minded states in key areas of military innovation.” Jake Sullivan, the US national security advisor, also presented an ambitious vision for AUKUS, which may include the advancement of shared security and the deepening of technological, economic, and climate cooperation in the Indo-Pacific region (Tan 2022). These American policy remarks suggest that AUKUS may become a non-exclusive initiative that “complements rather than contradicts the existing regional architecture and norms,” and thus, AUKUS will be “more boon than bane for ASEAN” (Tan 2022).

If the above analysis turns out to be true, it is highly likely that some ASEAN countries may be willing to engage with AUKUS as partners. ASEAN’s evolving attitude toward the Free and Open Indo-Pacific and QUAD could provide some clues for ASEAN’s future posture toward AUKUS. For many years, ASEAN has been resistant and lukewarm toward the QUAD. However, in recent years, ASEAN countries have become more positive when the QUAD began to propose various practical cooperative initiatives. This change of attitude can be seen in the statement of ASEAN-US special summit in 2022:

Noting that both the AOIP and the Indo-Pacific Strategy of the United States share relevant fundamental principles in promoting an open, inclusive, and rules-based regional architecture, in which ASEAN is central, alongside partners who share in these goals … In welcoming support extended by ASEAN Dialogue Partners through various initiatives, including the Quad Vaccine Partnership, we remain committed to facilitating equitable access to safe, affordable and quality medicine and health services (The White House 2022).

In fact, regional policy analysts have already suggested that ASEAN may be able to initiate a regional dialogue for ASEAN states, AUKUS partners, and China to reduce tensions and build as much trust as possible. Such a dialogue can be arranged within the ASEAN Regional Forum or East Asia Forum. Also, Marty Natalegawa, the former Indonesian Minister of Foreign Affairs, put forward a much bolder idea, suggesting that discussions on AUKUS could be linked to the Indo-Pacific Treaty proposal (Muntasyir and Santoso 2022).

AUKUS has sparked other geostrategic ideas as well. Given the fact that AUKUS will further intensify US–China strategic rivalry in the region and underscore the importance of the Strait of Malacca, Malaysia and other littoral states may consider the possibility of pursuing some creative alignments and partnerships to safeguard their national interests. One such idea is to further revitalize the Five Power Defense Agreement (FPDA) between the United Kingdom, Australia, New Zealand, Singapore, and Malaysia. The FPDA may be a good mechanism for Malaysia for two reasons. First, it is not aimed at active deterrence but centers on building a consultative defense arrangement. Second, it does not include the United States. In addition to the annual Exercise Bersama Lima and other communications activities, the FPDA may consider deepening cooperation in the cyber and electronic domains, as well as in other areas (Sigar 2022).

In the wider Indo-Pacific region, responses to AUKUS have been mainly positive. In Northeast Asia, despite some doubts, South Korea and Japan have welcomed AUKUS (Economist Intelligence Unit 2021). In fact, it has been suggested that Japan—a trusted partner of ASEAN countries, supporter of AUKUS, US ally, and a QUAD member—could help bridge ASEAN and AUKUS. One observer has proposed that Japan could help “establish an institutionalized way of communication and dialogue with like-minded countries surrounding the AUKUS operating area, including with ASEAN” (Irsadanar 2021). Indeed, in recent years, Japan has significantly deepened its security relations with Australia, as seen in the January 2022 signing of the “landmark treaty”: Japan–Australia Reciprocal Access Agreement (RAA) (Koga 2022).

5 Conclusion

AUKUS, despite still being in the early stages of its existence, has become a new geostrategic reality in the Indo-Pacific region, particularly given ASEAN’s cautious acceptance of AUKUS as part of the region’s strategic landscape. Regional states’ responses to AUKUS have been shaped by their concerns about the challenges to ASEAN centrality, possible negative impacts on regional stability, and their strategic approaches to relations with both the United States and China.

The geostrategic implications of AUKUS can be understood from several structural perspectives. Fundamentally, the emergence of AUKUS has to do with the intensification of US–China strategic rivalry and Washington’s new strategic approach to deal with the rise of China. AUKUS signifies a US strategy that centers on the balance of hard power, pursuit of effective deterrence, and, in the worst-case scenario, a Cold War confrontation with China. In this regard, if the US–China rivalry continues to grow, the implementation of AUKUS may become more substantive. As many policymakers and analysts have feared, it is indeed quite possible that AUKUS may spark a regional arms race in certain areas and on a limited scale, bringing about more challenges for regional stability.

Second, with the tacit acceptance of ASEAN and supportive views from other regional powers, it is likely that AUKUS may provide a prototype for a new and potentially more flexible mode of strategic realignment in the Indo-Pacific region. In the long run, more regional powers, including middle powers and smaller ASEAN states, may gradually gravitate toward AUKUS in the form of partnership or ad hoc issue-based cooperation. Different countries may decide to engage with AUKUS in selective areas. This essentially means that while most ASEAN countries will continue to practice their strategic hedging toward China, their tacit acceptance of and informal partnership with AUKUS will, at least to a limited extent, contribute to the strengthening of balance of power dynamics in the Indo-Pacific region. From this vantage point, one can argue that AUKUS is a major development toward the strategic encirclement of China.

Third, for China, there are many policy options. Maintaining relatively stable relations with the United States would be preferable. Improving relations with neighboring states, especially those that have territorial disputes with China, would be equally important. And continuing to consolidate relations with ASEAN and ASEAN member states is also crucial in the context of Beijing’s strategic response to AUKUS. In fact, this is a strategy that China has been practicing for quite some time. To achieve all these goals, leaders in Beijing may need to come up with innovative ways to significantly amend China’s neighborhood policy to handle various political and territorial disputes in the region. With the improvement and consolidation of ties between China and various regional players, it is possible that some of the most dramatic consequences in regional strategic realignment in association with AUKUS could be mitigated.