Southeast Asian countries are increasingly concerned about the intensifying great power rivalry, competition, and decoupling between the United States (U.S.) and China, which have caused spillover effects in the region. For the past 20 years, scholars have agreed that East and Southeast Asian countries have been adopting the “hedging” strategy. However, recent analyses express concerns that this long-held “hedging” strategy by Southeast Asia may soon be either abandoned or rendered ineffective if a major U.S.–China armed conflict emerges across the Taiwan Strait (Marston and Bruce, 2020; Ngeow, 2024).

Since the Taiwan Strait is geopolitically connected to the South China Sea, where Beijing, Taipei, the Philippines, Vietnam, Brunei, Malaysia, and Indonesia have overlapping territorial claims and sovereignty disputes, many Southeast Asian countries are concerned that the Taiwan contingency will likely trigger wider armed conflicts and crises across the South China Sea and Southeast Asia. The entire region could then be drawn into a U.S.–China conflict. Southeast Asia's long-practiced “hedging” strategy would be rendered ineffective or obsolete, forcing Southeast Asian countries to take sides with either the U.S. or China. The Taiwan contingency would significantly undermine the cohesion and functions of the Association of Southeast Asian Nations (ASEAN), divide the ASEAN region, and bring unprecedented crises, disruptions, and chaos to the countries in the Indo–Pacific region.

In response to these strategic and policy concerns, this article will first review the theoretical development of the “hedging” strategy among Southeast Asian countries in the English-speaking scientific literature. It will identify research gaps and envision a suitable methodological approach for Southeast Asian policymakers to better practice hedging amid increasing structural uncertainties resulting from intensifying U.S.–China rivalry and decoupling.

The review of key theoretical developments and research gaps identified above sheds light on future studies of hedging in Southeast Asia. In addition to generating “knowledge of understanding”, which previous studies have achieved, the relative shortage of “knowledge of anticipation” is necessary to fill the actual policy gaps of “contingency”, “worst scenario”, and “anticipate possibilities” (Goh, 2005; Matsuda, 2012). To effectively ascertain the security risks arising from the structural uncertainties in the U.S.–China great power rivalry, “knowledge of anticipation” should enable policymakers to envision different possible future scenarios and identify the plausible and probable scenarios in actual policy planning. These insights are essential for preparing for and pre-empting contingencies and avoiding worst-case scenarios. Therefore, the anticipatory approach and methodology of hedging strategy are warranted. To address these research gaps, the following questions will be explored in this article:

Since 2023, a growing body of analyses contributed by American and British think tankers and scholars has aimed at foreseeing and anticipating the possible future scenarios resulting from a potential “Taiwan contingency” (Boyd et al., 2023; Mazarr et al., 2023; Taylor and Guan, 2024). A strategic and policy consensus has emerged: should the U.S. and China engage in armed conflict over Taiwan, the U.S. would no longer be able to guarantee a military victory with absolute certainty, due to the closing structural–strategic gap and military capabilities of the two great powers in recent years. Nonetheless, because Taiwan is an integral part of the “East Asian first island chain”, the U.S. would eventually need to garner diplomatic support and military assistance from Asian allies and partners for joint intervention in a Taiwan contingency. The U.S. clearly has a security interest and strategic intent in preserving the divided-rule status quo across the Taiwan Strait by preventing Beijing from unifying Taiwan by force or consent (Allison and Glick-Unterman, 2021; Davis, 2022; Evans, 2021; Freeman, 2021; O'Hanlon, 2022a,c; O'Hanlon et al., 2022).

In Asia, U.S. allies and military bases and facilities are mainly located in Northeast Asia (i.e., Japan and South Korea), Southeast Asia (e.g., the Philippines, Thailand, and Singapore), and the Indo–Pacific region (e.g., Australia and the Diego Garcia Islands). When planning for a Taiwan contingency, it is impossible to separate future scenario planning from the geostrategic flashpoints in the Korean Peninsula, East China Sea, South China Sea, South Asia, and the Indian and Pacific Oceans (Boyd et al., 2023; Mazarr et al., 2023; Taylor and Guan, 2024).

According to a 2023 research report published by the American defense think tank RAND Corporation, when considering whether Asian allies and partners would decide to participate in a U.S.-led joint military campaign in a Taiwan contingency, this question is actually geopolitically connected with the situation and stability on the Korean Peninsula and the territorial disputes in the South China Sea. In other words, when deciding whether to join the U.S. in militarily intervening in a Taiwan contingency, an Asian ally would need to factor in its own national security interests and the specific, more immediate flashpoints it is facing (Table 1).

The security and stability of the Korean Peninsula involve at least four countries that possess nuclear weaponry: the U.S., China, North Korea, and Russia. To pre-empt the worst-case scenario of a nuclear war, anticipating the Taiwan contingency should also involve anticipating the Korean Peninsula contingency.

Since the Cold War, North Korean threats have been South Korea's main national security concern. However, in recent years, Seoul has become increasingly aware of the worsening U.S.–China relations and the growing strategic–military gaps between the two great powers. In 2021, for the first time, Seoul made a joint announcement with the U.S. government regarding the importance of maintaining peace and stability across the Taiwan Strait. In 2023, another U.S.–South Korea joint statement publicly declared that maintaining peace and stability in the Taiwan Strait is essential for the region's security and stability. As of 2023, U.S. military bases in South Korea host about 28,500 U.S. troops. Given South Korea's geographical proximity to mainland China, Taiwan, the East China Sea, the Yellow Sea, and the Sea of Japan, South Korea is a key littoral hub of the “Sea Lines of Communication” (SLOCs) connecting Northeast Asia with the Indo–Pacific region. These recent geopolitical and geo-economic developments have gradually increased South Korea's vulnerability, making it more susceptible to being drawn into a major U.S.–China armed conflict over Taiwan (Lee, 2024).

During the Cold War period (1947–1989), South Korea (Republic of Korea; ROK), Taiwan, and South Vietnam (Republic of Vietnam, 1955–1975) were U.S. allies on the Asian frontlines. While the three smaller Asian states commonly sought to reunify their nations with the lost or partitioned territories controlled by their communist competitors, South Korea and Taiwan actively sought to establish their own multilateral security alliances. During the Korean War (1950–1953), Taipei's Chiang Kai-shek government offered to send 33,000 troops to South Korea. During the Vietnam War (1955–1975), South Korea's Park Chung–Hee government deployed 300,000 troops to Vietnam to support South Vietnam. These actions indicated that Taipei and Seoul had similar policies in collaborating with the U.S. to counter the spread of communism in the region (Lee, 2024, p. 20–21).

Nonetheless, because of the U.S.-led “hub-and-spokes” alliance system in Asia, Seoul and Taipei rarely engaged in bilateral strategic coordination or mutual military arrangements. In the early 1970s, the U.S. formally recognized the People's Republic of China and established diplomatic ties with Beijing. The U.S. policy shifted from previously recognizing the Republic of China in Taipei to recognizing only the People's Republic of China as the legitimate government of China. The U.S. also withdrew troops from Vietnam in 1975. The Cold War ended in 1989. From 1991 to 1992, the end of the Cold War witnessed increasing domestic political pressure demanding the withdrawal of U.S. military bases from the Philippines, leading Manila to decide to close the U.S. military bases in the country. In 1992, South Korea also changed its recognition from the Republic of China (Taipei) to the People's Republic of China in Beijing as the legitimate government of China. These events reflected that the ideology of anti-communism was no longer effective in unifying the U.S., South Korea, Taiwan, and other Asian allies (Lee, 2024, p. 20–21). The importance of the U.S. alliance system was also in decline.

The U.S.-led “hub-and-spokes” alliance system implied that South Korea did not need to consider the defense needs of other U.S. allies. The 1953 Mutual Defense Treaty signed by the U.S. and South Korea stipulated that mutual defense was only applicable to scenarios in which either American territory or South Korean territory in the Pacific Ocean was attacked by a third-party country. In other words, the U.S.–South Korea security treaty neither covers the scenario in which a U.S. ally or partner country is under attack (such as Taiwan) nor applies to situations where U.S. military bases or personnel in Taiwan are attacked.

To many South Koreans, the purpose of the U.S. alliance was to mitigate threats from North Korea (Democratic People's Republic of Korea; DPRK). Fighting a war with America over Taiwan was outside the scope of the U.S.–South Korea treaty. In 2023, South Korean scholars suggested that it would be highly unlikely for South Korea to militarily intervene in a Taiwan contingency (Lee and Lee, 2023, p. 157). However, American think tank scholars did not rule out the possibility that U.S. military bases and/or American troops stationed in South Korea, Japan, the Philippines, Singapore, and Australia could be used to support a potential Taiwan Strait conflict (O'Hanlon, 2022b). Scholars also cautioned that because Seoul would want the U.S. to honor its security guarantee to defend South Korea against North Korea and to avoid undermining the U.S.–South Korea alliance, Seoul would not prevent the U.S. Forces Korea (USFK) from intervening in a Taiwan conflict. A close strategic interconnection exists between the Taiwan Strait and the Korean Peninsula. It is evident that South Korea will inevitably be impacted by a Taiwan contingency (Cho, 2023; Hsiao, 2023; Lee, 2024, p. 24).

According to the anticipations presented in Table 2, if China and the U.S. engage in armed conflict over Taiwan, South Korea (Republic of Korea; ROK) would find it very difficult to adopt the policy options of “complete neutrality” and “partial neutrality”, simply because these options would conflict with South Korean national security interests. These two options would not only damage the U.S.–ROK alliance and strategic trust but would also undermine the security guarantee that the U.S. provides to defend South Korea from North Korean threats. In a scenario where North Korea exploits a Taiwan contingency to launch attacks against South Korea, South Korea would need U.S. military support to aid in its defense.

The remaining policy option for South Korea would then be “partial involvement”. Originally, this option was mainly intended to decrease the likelihood that the ROK military would become tactical targets of the Chinese military. However, it would also make ROK military facilities and USFK assets potential tactical targets of the Chinese military. Because the U.S.–China conflict over Taiwan is unlikely to be resolved quickly, a protracted war could escalate into the “direct intervention” policy option, leading to a scenario where the ROK military joins the U.S. military to fight China over Taiwan. This situation would also increase the likelihood of North Korea attacking South Korea and the USFK, dragging the entire Korean Peninsula into a Taiwan military conflict. This policy option of “horizontal direct intervention” in a regional war would not only represent the “worst scenario nightmare” for South Korea but also raise the risk of an international nuclear armed conflict in Northeast Asia and beyond.

Whereas Beijing would strive to contain potential armed conflict with the U.S. to Taiwan, the U.S. would seek to internationalize the Taiwan conflict to encourage joint military intervention from its regional allies. A Taiwan contingency would likely spill over into Northeast Asia and the South China Sea, where Beijing, Taipei, the Philippines, Vietnam, Brunei, Malaysia, and Indonesia have overlapping territorial claims. However, from the perspective of South Korea, the worst scenario to avoid would be the spillover effects of the Taiwan conflict on the Korean Peninsula. The preferred future scenario would be the absence of any U.S.–China armed conflict over Taiwan. Therefore, it is in South Korea's interest to proactively prevent a Taiwan contingency from occurring. Proactively preserving the current peaceful status quo across the Taiwan Strait appears to be the best policy option for Seoul to consider.

As the Taiwan Strait is also geopolitically connected to the South China Sea, when South Korea considers devising a proactive policy to prevent a Taiwan contingency, Seoul would naturally need coordination and input from Southeast Asia. This would require a closer examination of the Philippines' hedging strategies, which have elicited divergent views among scholars.

Whilst the majority of scholars agree that the Philippines has been practicing evolving strategies of hedging (which include varying extents of balancing and bandwagoning acts) (Askari and Tahir, 2021; Banlaoi, 2021; De Castro, 2009, 2021; Liou and Hsu, 2017; Liu, 2024; Rodier, 2022; Tang, 2021; Weerasena, 2024; Wong, 2018: Chapter 2), a minority but influential scholarly position has persistently argued that the Philippines has actually been practicing (pure) balancing against China, which may imply containment (Kuik, 2016b: 169; Kuik, 2024). This minority position of “Philippine exceptionalism” deserves closer examination, promising a more comprehensive understanding of hedging strategies in Southeast Asia and allowing us to conceptually distinguish hedging from balancing and containment. Using the current administration of President Ferdinand “Bongbong” Romualdez Marcos Jr. (2022–present) for ethnographic fieldwork investigation, anticipation, and scenario planning, the following paragraphs illustrate why the Philippines has indeed stood out as an exception in Southeast Asian hedging.

Shortly after Marcos Jr. was inaugurated as the Philippine president in June 2022, I was invited by City Mayor Mrs. Maila Rosario Ting-Que to visit Tuguegarao City, the capital of Cagayan Province and the Cagayan Valley (Administrative Region II) in northern Luzon, in August 2022. After landing at Tuguegarao City airport, I was met by Mayor Ting-Que and the Philippine National Police regional commander. A government vehicle drove me to the mayor's residence—the Hotel Delfino. After I checked into the hotel, the mayor communicated with the Roman Catholic Archbishop of Tuguegarao, the Most Reverend Ricardo Baccay, for me to visit his office in the afternoon. In the following days, I met and discussed matters with other Philippine officials, professionals, lawyers, researchers, and businesspeople in meetings inside the hotel, the mayor's office, and other designated venues.

A field trip was also arranged to visit the Archdiocese-administered higher learning institutions—the Lyceum of Aparri and the Thomas Aquinas Major Theological Seminary—along the northern coast of Cagayan Province. In Aparri, in addition to meeting with faculty members, I engaged with students, informed researchers, senior clergy, and parishioners about the evolving geopolitical situation facing the coastal community. I was accompanied by clergy to visit selected locations along the northern coast, including government offices, mining fields, construction sites, coastal farmlands, parishes, and abandoned buildings and machinery left by China-related entities. From the 1st day's contacts and conversations with the mayor, police, and the Archbishop, I understood that this trip involved governmental representatives and the Catholic Church's policymakers. While I assessed the local situations against the backdrop of superpower geopolitics, I was able to engage with various local perspectives and offer my initial assessments during this trip for the Philippine government and the Catholic Church.¹

As a cultural pattern in Philippine local and national politics, Mayor Maila Ting-Que's family members have also served in the governments of Tuguegarao City and Cagayan Province, as well as in the Philippine Congress, as elected mayors, councilors, and congressmen since 1986. During the martial law regime (1972–1986) under former President Ferdinand Emmanuel Edralin Marcos Sr. (current President Marcos Jr.'s late father), northern Luzon was the political stronghold of the Marcos family, which hails from the adjacent Ilocos Norte Province. Mayor Maila Ting-Que's late father, former Tuguegarao City Mayor (1988–1998; 2007–2013) Mr. Delfin Telan Ting (1938–2022), aligned with the Marcos Sr. government's anti-communist ideology and counter-insurgency policies when Cagayan Province was troubled by communist insurgency. Since then, the two political families have become long-time allies.

In the 2022 national election, the Ting family campaigned for Marcos Jr.'s presidency. For more than two decades, my relationships with the Philippine political elite have deepened as my research on the Philippines continues (Wong, 2024). My August 2022 field trip to northern Luzon and Manila, along with post-fieldwork research, generated several key findings for anticipating Philippine responses to a Taiwan contingency.

In the first place, Taipei has already controlled three disputed islands in the South China Sea. The first is the Pratas Islands (Tungsha Islands; 東沙群島), which are administered by Taiwan's Kaohsiung City government and disputed by the Guangdong Provincial government of the People's Republic of China. The Pratas Islands occupy a geostrategically sensitive location as the maritime mid-point connecting southern Taiwan (410 km), Hong Kong (320 km), and northern Philippines (490 km); they connect the SLOCs leading to (1) the Taiwan Strait, (2) the Luzon Strait, and (3) the South China Sea (Figure 5). As of November 2020, about 500 Taiwanese marines were stationed on the Pratas Islands. The main island has a network of underground bunkers. Given the geostrategic location of the Pratas Islands, recent PLA military exercises in nearby areas were perceived to show an intent to cut off supply lines connecting Taiwan and the Pratas Islands in a Taiwan contingency scenario.

The second Taipei-controlled disputed island is Taiping Island, which is the largest in the entire disputed Spratly Islands (Figure 6). While it is administered by Taiwan's Kaohsiung City government, it is also disputed by Beijing, Vietnam, and the Philippines. On Taiping Island, Taiwan authorities have maintained electricity generators, an aircraft runway, a hospital, radar equipment, a lighthouse, and military facilities. Through Taiping Island, Taipei has also maintained control over the adjacent uninhabited Zhongzhou Reef by regularly having it patrolled by Taiwan's Coast Guard Administration.

The strategic value of Taiping Island for the Taipei government is significant; it serves as Taiwan's pivot in the South China Sea. In January 2013, the Philippines initiated arbitration proceedings against China in the Permanent Arbitration Court (The Hague) under the United Nations Convention on the Law of the Sea (UNCLOS), including China's historic rights and sovereignty claims over parts or all of the Spratly Islands. The Philippines won the case in 2016, but like Beijing, Taipei also did not recognize the ruling.

The second finding concerns how changing U.S.–China dynamics in recent years across the Taiwan Strait have caused major changes in the Philippines' assessment of its external security environment. Manila has had to deal with at least three anticipated future scenarios of complex security challenges (Patton, 2022).

First anticipated scenario: If armed conflict occurs over Taiwan, the Philippines will inevitably be impacted due to its geographical proximity to Taiwan. During the Vietnam War (1955–1975), thousands of South Vietnamese soldiers and refugees evacuated from Vietnam to the Philippines, causing humanitarian crises. It was estimated in 2022 that there were at least 200,000 overseas Filipino workers (OFWs) living and working in Taiwan. The families of these OFWs in the Philippines would likely have a significant influence on the Philippine government's decision-making in a Taiwan contingency. Philippine government officials have already outlined emergency evacuation plans from Taiwan (Patton, 2022).

Second anticipated scenario: If Beijing succeeds in reuniting Taiwan, Manila's territorial claims in the South China Sea will be jeopardized. The 2016 Philippines' international legal arbitration victory over Beijing under UNCLOS was not recognized by Beijing. This arbitration outcome, however, worsened China–Philippines relations. Since the Philippines filed the arbitration case in 2013, China has built military-use artificial islands in the South China Sea, which further constitutes serious national security threats to the Philippines. When Beijing seeks to take control of Taiwan and the Taiwan Strait, the Chinese military will also seek to control the disputed islands and islets in the South China Sea occupied by Taipei. This would aim to expand China's military control in the South China Sea, which would be detrimental to Philippine national security. The Philippines would therefore wish to preserve the current divided-rule status quo across the Taiwan Strait (Patton, 2022).

Third anticipated scenario: The U.S. military's controversial withdrawal from Afghanistan in August 2021 significantly weakened America's credibility among its Asian allies. The Philippines was also concerned about the diminishing military-strategic advantage that the U.S. previously held over China (Allison and Glick-Unterman, 2021; O'Hanlon, 2022b). As the Philippines is America's treaty ally, there is a high risk that it could be affected by, if not dragged into, a cross-Strait conflict between Beijing and Taipei, as well as America. However, if the U.S. decides not to aid Taiwan, Manila would need to seriously consider adopting a stance of neutrality in a Taiwan contingency. Additionally, if the Philippine government decides to militarily support the U.S., Manila is likely to be accused by Beijing of collaborating with the U.S. to contain China militarily. The Philippines would then become a tactical target for the Chinese military. Under the ongoing trend and turbulent dynamics of U.S.–China decoupling, a Taiwan contingency scenario has created a significant security dilemma for Manila, leading to strategic passivity that limits the Philippines' options for maneuvering and hedging between the U.S. and China.

The third key finding was established through my field research in the northernmost Philippine coastal province of Cagayan in August 2022. Cagayan is the nearest Philippine province to Taiwan, with its islands located only about 190 km from the southern coast of Taiwan. The geostrategic islands of Cagayan (e.g., Fuga Island) control access to the Luzon Strait shipping lanes, which connect the Pacific Ocean, the South China Sea, and the Taiwan Strait, as well as the trans-Pacific submarine cables. In April 2022, for the first time, the U.S. military and the Philippine military conducted their joint “Balikatan (Filipino language meaning: shoulder-to-shoulder)” military exercise along the coast of Cagayan Province (Editorial, 2022; Mangosing, 2022a,b; Ong, 2022). It is safe to suggest that Cagayan Province and its islands in the Luzon Strait are part of the “East Asian first island-chain”.

Philippine analysts reported that in recent years, Chinese enterprises attempted to invest in Fuga Island and the nearby maritime area. These proposals were opposed by the Philippine military and the Philippine Department of National Defense (Crismundo, 2020; Heydarian, 2019). Since 2007, mining operations by China and other East Asian countries have existed in the Cagayan River Valley and the Luzon Strait. Coastal mining activities by Chinese companies also caused disputes involving the government and the church, along with protests and conflicts from local farmers, fishermen, and communist insurgents (Saludes, 2021; Wong et al., 2013, 2015). My August 2022 fieldwork suggested that attempts to purchase coastal farmland by alleged Chinese proxies were rejected by local Filipino landowners. Monetary gifts made by these alleged proxies to the Roman Catholic Church were also intercepted and rejected by the Archbishop of Tuguegarao.

For more than two decades, businesspeople of Chinese citizenship have operated offshore online gaming and physical gambling facilities in the Philippines, specifically in the northeastern port town of Cagayan Province, Santa Ana. These offshore gaming and gambling facilities were licensed by the Philippine government. They were allowed to operate exclusive casinos solely for foreign tourists, particularly those coming from mainland China. According to sources in the Philippine Catholic Church, in recent years, as tensions across the Taiwan Strait grew, parishioners noticed an increased presence of military-aged Chinese individuals in Santa Ana. One day in 2022, a parishioner found a wallet on the street that contained an unverified identity card of the People's Liberation Army (PLA). While the wallet was handed to the Philippine police, the Catholic Church also reported the unusual incident to Philippine military intelligence. Local suspicions had already suggested that alleged PLA intelligence agents or scouts were present in Santa Ana and the adjacent coastal areas. The perceptions I gathered in Cagayan Province and Manila indicated that because Cagayan Province's geographical proximity to the Taiwan Strait and its geostrategically sensitive location, if an armed conflict were to occur over Taiwan, Cagayan Province would likely become a battlefield, and the entire Luzon Island would inevitably be impacted.

The fourth key finding concerned the Marcos Jr. government's 2023 decision to install new U.S. military bases in Cagayan Province and northern Luzon (Figure 7) (Cepeda, 2023; Editorial, 2023; Venzon, 2023). In 2014, former Philippine President Benigno Aquino III signed the “Enhanced Defense Cooperation Agreement (EDCA)” with the Obama administration. EDCA was judged by the Philippine judiciary to be constitutional in 2016. By allowing the U.S. to use five Philippine military bases for training, infrastructure construction, storage facilities, and other mutually agreed activities, EDCA aimed to strengthen U.S.–Philippines security cooperation. In 2020, the Duterte government requested Beijing to comply with the 2016 South China Sea international arbitration outcome, which worsened Philippines–China relations. From 2016 to 2022, in an attempt to avoid escalating conflict with Beijing, former Philippine President Rodrigo Duterte did not implement the respective EDCA clauses that allowed U.S. access to and use of Philippine military bases.

When Marcos Jr. was elected president in 2022, some Philippine scholars suggested that the Philippines' hedging strategy regarding the U.S.–China relationship necessitated a review and fine-tuning. A main driver was that the intensifying U.S.–China competition had recently evolved into economic–technological decoupling and a new Cold War. As Southeast Asia's major treaty ally, the Philippines faced increasing structural pressures and uncertainties to take sides. However, continued turbulence in American domestic politics, the U.S. military's chaotic withdrawal from Afghanistan in 2021, and the growing military-strategic distance between the U.S. and Chinese militaries have led the Philippines to recognize that the U.S. may not be able to guarantee a decisive military victory in a Taiwan contingency. If the Philippines chooses to fully align with the U.S., an open war scenario with China will bring tremendous misery and suffering to the Filipino people.

Therefore, in contrast to Duterte's hedging strategy aimed at de-escalating conflict with China, the Marcos Jr. government's hedging strategy has clearly shifted toward a more specific anticipatory strategic purpose of balancing against a Taiwan contingency worst scenario, which also aims to prevent the Philippines from being dragged into a regional war (Table 3). In particular, Marcos Jr.'s major decision was to allow the U.S. military access to the following three new Philippine military bases in the Cagayan Valley Region:

I consider these to be President Marcos Jr.'s primary strategic and security considerations: a Taiwan contingency would likely lead to the following undesirable/worst scenarios. The Philippines had to resort to the above EDCA-approved U.S. military basing measures to prevent or deter the anticipated escalations of armed conflict from occurring across the Taiwan Strait and into the South China Sea.

First, a Taiwan contingency will cause ~200,000 Filipinos/OFWs in Taiwan to return to the Philippines. This scenario will negatively impact the Philippine economy by cutting off remittance incomes and economic benefits coming from Taiwan.

Second, a Taiwan contingency will result in an unprecedented number of war refugees and political asylum seekers flooding from Taiwan into the Philippines. This would not only lead to major humanitarian crises and suffering but also weaken the Philippines' national security and internal social stability.

Third, a Taiwan contingency will prompt the U.S. and its allies to impose sweeping economic and financial sanctions on China. Because mainland China has been the largest trading partner of the Philippine economy, the China–Philippine trade flows and economic volumes will be severely curtailed by these sanctions. The Philippine economy will be significantly damaged, leading to widespread unemployment, a major economic crisis, devaluation of the Philippine peso, and social unrest.

Fourth, in a Taiwan contingency, Beijing would seek to militarily take over the Taipei-controlled islands in the South China Sea, which the Philippines and Vietnam also claim. A U.S.–China armed conflict over Taiwan could easily escalate and spill over into an international conflict in the South China Sea. This would significantly undermine ASEAN's unity and ongoing efforts to resolve maritime–territorial disputes peacefully and orderly, and it could potentially weaken the Philippines' sovereignty claims and legal rights in the South China Sea disputes.

Fifth, in a Taiwan contingency, because of the Philippines–U.S. alliance and the EDCA military basing arrangements that already grant the U.S. access to Philippine military bases, it is nearly impossible for the Philippines to adopt a “complete neutrality” or “partial neutrality” policy. It is reasonably anticipated that, in the escalations from the point of “partial involvement” onward, the Philippines will eventually join U.S. forces in a full-fledged war against China over Taiwan and the South China Sea, and potentially in Northeast Asia (Table 3).

In summary, President Marcos Jr.'s decision and motivation to allow the U.S. military back into Philippine bases were neither to express support for the “Taiwan independence” forces, nor primarily aimed at helping the U.S. offshore-balance or contain China, nor to exhaust China's resources. Instead, Marcos Jr. intended to leverage the U.S. alliance and security guarantees to deter a Taiwan contingency, in order to protect the Philippine national economy and security interests, maintain domestic social stability, and uphold the country's legal rights in the South China Sea. These were essential for the legitimacy of Marcos Jr.'s regime.

Unlike Japan, South Korea, Australia, and the Philippines, most Southeast Asian countries today are not U.S. treaty allies. They are less constrained by factors such as the U.S. alliance treaty, the stationing of U.S. forces, and military basing arrangements. When anticipating how Southeast Asia would respond to a Taiwan contingency, the considerations of these Asian partners warrant our attention. Vietnam is therefore chosen for examination. A primary reason is that, as one of the competing claimants of the disputed Spratly Islands in the South China Sea, like the Philippines, Vietnam also has overlapping sovereignty claims on the Taipei-controlled Taiping Island (Chinese: 太平島; Itu Aba) and Zhongzhou Reef (Chinese: 中洲礁; Ban Than Reef). Taiping Island is adjacent to three Vietnam-controlled islands: Namyit Island, Sand Cay, and Petley Reef, which are also disputed by Beijing, Taipei, and Manila (Nguyen, 2024, p. 53).

If the U.S. and China engage in armed conflict over Taiwan, the Philippines will likely be militarily involved (as anticipated in the previous section), which would likely trigger further armed conflicts in the disputed South China Sea. Vietnam would naturally fear that the dual conflicts in Taiwan and the South China Sea will weaken its existing interests, sovereignty claims, and rights in the region. Moreover, because the South China Sea disputes involve multiple parties, despite Vietnam considering staying neutral at the beginning, Hanoi would soon find itself possibly entangled in a series of concomitant conflicts with various parties across multiple theaters. However, the outcome of such a multi-frontal conflict scenario would not necessarily be favorable to Vietnam. A Taiwan contingency has therefore created an anticipated series of security dilemmas for Vietnam.

I believe that Vietnam does not wish to see a Taiwan contingency occur because such a crisis would likely escalate conflicts and lead to multiple crises for Vietnam (Table 4). These conflicts and crises would bring substantial uncertainties and security risks to Hanoi, which would seriously damage Vietnam's internal stability and economic development.

In the first place, Vietnam supported Beijing's “One China principle”. Hanoi did not maintain formal diplomatic relations with Taipei. During the Vietnam War (1955–1975), given their common anti-communist cause, Taipei's Kuomintang government maintained formal relations with the government of South Vietnam (Republic of Vietnam; 1955–1975). After the Vietnam War, North Vietnam (Democratic Republic of Vietnam) unified South Vietnam and established the “Socialist Republic of Vietnam”, which exists to the present day.

It was only in 1992 that Taipei re-established informal relations with Hanoi by setting up the “Taipei Economic and Cultural Office” in Hanoi and Ho Chi Minh City. In 1993, while successfully signing a bilateral investment agreement with Taipei, Vietnam established its own economic and cultural offices in Taiwan. Since then, Taiwan has been a major investor in Vietnam. By the end of 2022, it was estimated that there were 2,900 Taiwan-invested projects in Vietnam, with a total value of 36 billion U.S. dollars. From 2019 to 2022, Taiwan was also among Vietnam's top five importing countries, surpassing the U.S. and the European Union (E.U.) (Table 5). The main commodities in Taiwan–Vietnam bilateral trade included computers, electronic products, parts and components, and machinery. Vietnamese local governments actively attracted Taiwanese companies to invest in the electronics and semiconductor industries by offering special policy concessions and administrative convenience to Taiwanese enterprises (Nguyen, 2024, p. 48).

As of 2023, Vietnam's economic and cultural office in Taiwan estimated a total of 400,000 Vietnamese living in Taiwan. Approximately 250,000 of them were part of Taiwan's active labor force, mainly serving in the manufacturing, healthcare, and home care service sectors. Under the Taipei government's active implementation of the “New Southbound Policy” (Chinese: 新南向政策) since 2016, Vietnam aimed to deepen relations and expand cooperation with Taiwan in education, tourism, trade, and talent exchange (Nguyen, 2024, p. 49).

Since 1986, when Vietnam adopted Deng Xiaoping's policy to implement economic reforms (Vietnamese: Ðôi Mói), Hanoi has pursued a multilateral and “omnidirectional foreign policy” (Nguyen, 2024, p. 54). Since then, Vietnamese policy has aimed at establishing itself as a reliable partner and friend to all nations. Vietnam has not only managed to mend relations with the U.S. and China but has also normalized its relationships with Southeast Asian neighbors. This policy has helped Vietnam create a stable external security environment for national economic development. The economic pragmatism behind this policy explains why Vietnam seeks to deepen its economic and trade relations with Taiwan. Moreover, Vietnam is eager to learn from Taiwan's successful industrialization experience and economic development miracle, enabling Vietnam to become another high-end industrialized, developed economy (Nguyen, 2024, p. 50).

For Vietnam, a Taiwan contingency would likely lead to at least three overlapping crises. First, the fate of the 400,000 Vietnamese living in Taiwan would be in question. In February 2022, when the Russia–Ukraine War began, Vietnam managed to evacuate 2,600 citizens from Ukraine. However, this evacuation process faced difficulties, as these citizens needed to find their own ways to reach airports in Poland and Romania before boarding the arranged flights. In a Taiwan contingency, Vietnamese citizens would likely request the Hanoi government to evacuate the 400,000 Vietnamese from Taiwan. This challenging mission could lead to serious humanitarian crises and refugee problems that would undermine Vietnam's domestic political stability (Nguyen, 2024, p. 51–52).

Second, a Taiwan contingency would seriously disrupt or even halt trade and investment flows between Taiwan and Vietnam. This disruption would cause significant shortages of critical commodities, negatively affecting Vietnam's production and exports. One of the most affected sectors would likely be Vietnam's fast-developing semiconductor industry. Taiwan is a major production base for semiconductors and chips, accounting for 92% of the world's most advanced semiconductors and one-third of high-end complex chips. A Taiwan contingency would severely impact global chip flows and semiconductor supply chains. Vietnam's ambitions and plans to become a future manufacturing base for semiconductors would likely be frustrated and suspended (Nguyen, 2024, p. 52).

Third, a Taiwan contingency would prompt many foreign investors and enterprises to withdraw from the markets of mainland China and Taiwan. While Vietnam might benefit from the reallocation of these investments in the long run, it would immediately suffer significant losses in its trade with China, its largest trading partner in recent years (Table 4). Western financial sanctions against China would also severely impact global trade, from which Vietnam has benefited. A Taiwan contingency would likely lead to surging unemployment rates, drastic economic contraction, and significant currency devaluation, resulting in a multi-layered national economic crisis for Vietnam.

Fourth, a Taiwan contingency would likely spill over into the disputed islands in the South China Sea. For instance, Vietnam would need to prepare contingency plans to respond to any armed incidents on the Taiwan-controlled Taiping Island (Nguyen, 2024, p. 53). If China and the U.S. engage in armed conflict over Taiwan, Vietnam's national development strategy, which depends on a stable external security environment, would be jeopardized. The Hanoi government would be forced to alter Vietnam's multilateral diplomacy and omnidirectional foreign policy adopted since 1986. Vietnam would then face greater structural pressures from a new Cold War, forcing it to take sides. Such a policy shift could trigger uncertainties, diplomatic conflicts, domestic instabilities, and political crises.

In sum, Vietnam does not consider a Taiwan contingency scenario to be in its interest at all; Hanoi has good reasons to want to prevent such a scenario. A Taiwan contingency would lead to multiple crises for Hanoi. Naturally, Hanoi would wish to collaborate with ASEAN and external partners to prevent it from occurring. Preserving the current divided-rule status quo across the Taiwan Strait and pre-empting a Taiwan contingency seems to be a viable, if not the only, way forward that ASEAN member-states and external partners should consider in order to reach consensus and resolutions.

The above case studies have contributed several novel conceptual advances to Southeast Asian hedging strategies. First, hedging is conceptually distinguished from balancing, which suggests containment. The hedger's core strategic self-identity and intent differ from those of the offshore-balancer, who may inadvertently or deliberately work for an external great power to balance against, contain, or weaken the neighboring great power in dispute. The hedger's primary strategic intent is to strategically use the great power rivalry to achieve its own national security goals and enhance its capacity to defend territorial integrity and sovereignty from the disputing great power.

Second, in response to scholarly concerns that the shrinking space for hedging and erosion of maneuverability are being exacerbated by the U.S.–China great power rivalry and the potential for armed conflict, this article demonstrates that a futurist methodology of anticipation can not only mitigate the problems of shrinkage and erosion but can also proactively preserve and pre-emptively enlarge the space, agency of maneuverability, strategic flexibility, and range of hedging policy options.

In other words, anticipation adds a new conceptual dimension to the existing dualism of hedging found in Figure 1. Using the two-axis four-quadrant anticipatory framework for illustration, the advanced hedging model is now represented in Figure 8. With the practice of a new anticipatory hedging strategy (distinguished from non-anticipatory hedging strategy), the anticipator-hedger would be more capable of astutely utilizing selected policy tools from neorealism, neoclassical realism, and norms competition to increase strategic maneuverability, gain flexibility, expand policy options, and enjoy a higher degree of freedom to hedge against future uncertainties, at least pre-emptively identifying and preventing the worst-case scenario from occurring.

In conclusion, several key lessons have been learned. First, on the one hand, the rise of China over the past three decades has brought significant economic and trade benefits, as well as developmental opportunities, for Southeast Asia to enhance national economies and regional development. On the other hand, territorial disputes in the South China Sea and China's growing political influence and military might have also introduced new security risks arising from the structural uncertainties not only of a rising China but also of intensifying China–U.S. geopolitical-economic competition in the Indo–Pacific region. Regional flashpoints in the South China Sea, East China Sea, and the Korean Peninsula are strategically interconnected with stability across the Taiwan Strait. A Taiwan contingency would likely spill over into other regional flashpoints, potentially triggering concomitant armed conflicts in Northeast Asia and Southeast Asia. Depending on the circumstances, a Taiwan conflict might even spill over into flashpoints in South Asia and territorial disputes in the Himalayas.

Second, Southeast Asia's hedging strategies are believed to have brought positive economic gains and significant trade benefits to smaller, medium-sized, and emerging powers in the Indo–Pacific region. Additionally, these hedging strategies have been effective due to U.S. security guarantees, military provisions, and alliance partnerships. The U.S.'s economic and security presence in Asia is regarded as an asset to hedge against structural uncertainties and security risks arising from a rising China, but it could also be a source of geopolitical tension and potential armed conflict because of the intensifying U.S.–China great power rivalry.

Third, a Taiwan contingency would significantly shrink the strategic maneuvering room for small- and medium-sized states in Southeast Asia and Northeast Asia. In the case of U.S. allies like South Korea and the Philippines, assuming U.S. military intervention in a Taiwan contingency against China's armed invasion, these allies would be under unprecedented pressure to honor and uphold the U.S. alliance in defending against national security threats from North Korea and China in the Korean Peninsula and South China Sea, respectively. As a result, they would likely join U.S. forces in armed conflict against China over Taiwan.

Given that a Taiwan contingency would likely spill over into the Korean Peninsula and South China Sea, it is in the interests of both South Korea and the Philippines to prevent such a contingency from occurring. Preserving the current peaceful divided-rule status quo across the Taiwan Strait aligns with the interests of both South Korea and the Philippines.

For non-U.S. treaty allies in Southeast Asia, such as Vietnam, a Taiwan contingency would likely expose Hanoi to increased vulnerabilities and security risks both domestically and internationally. With 400,000 Vietnamese living and working in Taiwan, the Hanoi government would quickly find itself embroiled in multiple overlapping domestic political, economic, humanitarian, and international crises that would significantly undermine the legitimacy of the ruling Communist Party of Vietnam.

As the Philippines would likely be militarily involved in a Taiwan contingency that could spill over into the disputed islands in the South China Sea, Vietnam's claims in the South China Sea and its trade relations with mainland China and Taiwan would also likely be jeopardized. In such a multi-crisis scenario, neither siding with the U.S.-led alliance nor siding with China would guarantee a favorable outcome for Vietnam's claims in the South China Sea. In addition to the domestic and international economic crises that Hanoi would face, further uncertainties regarding Vietnam's claims in the South China Sea would compel Hanoi to reconsider and possibly change its reform-centered foreign policy agenda. Thus, it is also in Vietnam's interest to prevent a Taiwan contingency from occurring.

In conclusion, to maintain the necessary conditions for a peaceful security environment conducive for small- and medium-sized states in Asia to hedge between the U.S. and China, it is in the interests of U.S. allies, partners, and non-allies to work together to preserve the peaceful divided-rule status quo across the Taiwan Strait by developing and adopting new anticipatory hedging strategies. Southeast Asian countries should therefore collaborate with ASEAN partners, including South Korea, to prevent the Taiwan contingency—a common nightmare scenario—from occurring.