Navigating Tensions in the South China Sea: A Multidimensional Analysis
By Megan Wei, University of Chicago
The South China Sea has long been a flashpoint for regional tension, with competing territorial claims at the heart of a complex and evolving geopolitical struggle. Stretching from the Strait of Malacca to the Strait of Taiwan, this vital waterway includes hundreds of islands, reefs, and rocks, most notably in the Paracel and Spratly chains. The South China Sea is a cornerstone of global trade, accounting for one-third of all maritime commerce and containing rich undersea resources like oil, natural gas, and fish.[1] Beyond its economic significance, the region serves as a strategic chokepoint for international shipping and offers significant military leverage, making it a flashpoint for sovereignty disputes and concerns over freedom of navigation and regional security.[2] Territorial claims from Vietnam, the Philippines, Taiwan, and China are driven by competing interests in sovereignty, security, and control over key shipping lanes. China’s aggressive military expansion in the region has heightened tensions, forcing neighboring nations to reevaluate their strategies and alliances. Meanwhile, the United States, though not a direct claimant, has voiced concerns about China’s violations of freedom of navigation and regional security. However, the U.S. has struggled to present a consistent and decisive response to China’s assertive actions, undermining its ability to counterbalance China’s growing influence. This power dynamic between major nations has left smaller states like Vietnam, the Philippines, and Taiwan increasingly vulnerable. Ultimately, this combination of China’s growing military presence and the U.S.’s contradictory policies exacerbates the vulnerability of smaller nations like Vietnam, the Philippines, and Taiwan, making the establishment of a cohesive, rules-based order in the South China Sea increasingly unfeasible.
The South China Sea remains a crucial battleground for Vietnam, where territorial disputes and geopolitical maneuvering converge. Navigating this volatile environment requires Vietnam to assert its sovereignty while managing its complex relationship with China, its largest neighbor and the primary source of maritime pressure. Vietnam bears a disproportionate share of coercive incidents in the South China Sea, with Chinese forces consistently targeting its fishing and oil exploration vessels through military intimidation and maritime law enforcement tactics.[3] These actions have made Vietnamese vessels the primary focus of aggression in the region. This persistent harassment extends beyond disputes over maritime rights, reflecting China’s broader regional ambitions and underscoring Vietnam’s vulnerability due to its comparatively smaller military capabilities and limited geopolitical influence. The 2014 HD-981 crisis exemplifies China’s aggressive approach toward Vietnam. By deploying an oil rig within Vietnam’s exclusive economic zone (EEZ), China provoked widespread protests and violent confrontations at sea.[4] This incident showcased China’s reliance on gray-zone tactics, employing irregular forces to assert dominance without triggering full-scale military conflict. Despite Vietnam’s efforts to resolve the crisis diplomatically—such as filing official complaints and publicizing China’s actions—China escalated tensions by ramming Vietnamese ships and deploying water cannons. Vietnam’s response, primarily diplomatic in nature (40% of the time), involved limited confrontations and public communication, reflecting the country’s preference for non-military solutions. However, the crisis demonstrated that when diplomatic measures proved ineffective, Vietnam had no choice but to engage in direct confrontation, underscoring the immense difficulty of countering China’s growing maritime assertiveness with its relatively limited resources.
In recent years, Vietnam has fortified its outposts in the Spratly Islands, reaffirming its commitment to asserting territorial claims amid growing pressure from China.[5] This determination is shaped by Vietnam’s nuanced diplomatic strategy, underscored by its Comprehensive Strategic Partnership with China, established in 2013, and a parallel agreement with the United States in 2023.[6] These contrasting alliances reflect Vietnam’s dual approach of balancing cooperation with resistance in navigating its foreign policy challenges. This period of strategic maneuvering coincides with a significant political transition, as newly elected President Luong Cuong assumed office on October 21, 2024. Bill Hayton, Associate Fellow with the Asia-Pacific Programme at Chatham House, observed that “the new leadership in Hanoi may bring Vietnam closer to China’s strategic interests, as it shares more ideological common ground with China and Russia than with the West.” [7] While Vietnam and China maintain historical ideological ties, deeper cooperation under the new administration could prompt a more cautious approach to maritime disputes, prioritizing stability over direct confrontation. Although this pragmatic stance might temporarily ease tensions, it risks compromising Vietnam’s ability to fully assert its sovereignty in the South China Sea. The enduring legacy of Chinese aggression, however, will likely continue to shape Vietnam’s strategic choices, compelling it to strengthen external alliances, particularly with the United States, to bolster its security. The U.S. supports Vietnam by challenging China’s claims in the South China Sea through Freedom of Navigation Operations, enhancing Vietnam’s maritime capacity, and aligning its regional policies with Hanoi’s interests.[8] While recent political shifts suggest a potential pivot toward greater cooperation with China, the persistent history of coercion ensures that Vietnam will maintain efforts to assert its territorial claims through diplomacy and calibrated confrontation. As a result, the challenge of establishing a rules-based order in the South China Sea becomes even more complex, as Vietnam, along with other stakeholders, must navigate the dual pressures of managing territorial disputes and an increasingly intricate geopolitical landscape in the Indo-Pacific.
The Philippines' role in the South China Sea disputes underscores the growing difficulties of establishing a unified, rules-based order in the region. The country faces a complex set of territorial claims, historical grievances, and shifting strategic priorities amidst China's increasingly assertive actions. Unlike some other claimants, the Philippines’ territorial claims primarily focus on the Spratly Islands, which it justifies on historical grounds, citing the discovery of the islands by Filipino explorer Tomas Cloma in 1947.[9] However, due to its relatively smaller military and geopolitical stature, along with its geographic proximity to China, the Philippines is particularly vulnerable to frequent maritime confrontations. These disputes often involve direct military standoffs and economic coercion, including trade sanctions and diplomatic pressure, as China seeks to assert its dominance in the region. A notable example of the Philippines’ vulnerability occurred in the 2012 standoff over Scarborough Shoal. What began as a Philippine attempt to detain Chinese fishermen quickly escalated when China deployed maritime forces to prevent the Philippines from asserting control over its claimed waters.[10] Despite initial diplomatic efforts, including an informal agreement brokered by the United States for both sides to withdraw, China ultimately reneged on the deal and solidified its control over the shoal. Moreover, China employed economic tactics, including sanctions on Philippine exports like bananas and a travel advisory warning Chinese tourists against visiting the Philippines due to potential danger, to exert pressure on the country's position.[11] This incident exposed the limitations of the Philippines’ unilateral efforts to assert its claims and highlighted China’s broader strategy of combining military power with economic leverage to undermine smaller claimants and consolidate its territorial control.
The Philippines' increasing reliance on U.S. military support has become more pronounced in recent years, marked by significant defense agreements, including one in 2024 that allocated $500 million in U.S. military aid to modernize the Philippine armed forces.[12] This partnership signals the Philippines' shift toward a more assertive military posture, bolstered by American resources to counter China's maritime aggression. Additionally, the Philippines has sought to broaden its regional alliances, strengthening defense ties with countries like Japan, Germany, and Vietnam, reflecting a strategic pivot toward collective security. However, this deepened cooperation with external powers, particularly the U.S., complicates the geopolitical situation in the South China Sea. While these alliances are crucial for countering China's dominance, they risk intensifying tensions, as Beijing perceives them as efforts to contain its growth and limit its development and influence. The growing divide between China-aligned nations and those challenging China's regional control further complicates efforts to foster regional stability and cooperation. This dynamic highlights the broader challenges smaller nations like the Philippines face in balancing territorial sovereignty, national security, and international diplomacy—especially when U.S. support, although vital, remains unpredictable. Despite its alignment with the U.S. and other regional powers, the Philippines remains vulnerable to China’s growing assertiveness. As tensions continue to mount, the Philippines' strategy—while enhancing its military and diplomatic stance—contributes to the fragmentation of the region, making the establishment of a cohesive, rules-based order in the South China Sea increasingly unlikely.
Taiwan holds a unique, yet often marginalized, position in the South China Sea disputes due to its control over key islands like Taiping Island and its strategic interest in safeguarding territorial integrity. In contrast to China’s militaristic expansion, Taiwan has adopted a more restrained approach, prioritizing diplomacy and international law to address territorial disputes.[13] Taiwan advocates for resource-sharing and peaceful dialogue, standing in stark contrast to China’s aggressive land reclamation and military buildup in the Spratlys. Rather than pursuing new territorial claims, Taiwan has focused on defending its established positions, maintaining a relatively moderate role in the conflict.[14] However, as China intensifies its pressure—through both military actions and economic coercion—Taiwan’s position is becoming increasingly untenable. China’s insistence on the one-China policy exacerbates Taiwan’s situation, undermining its sovereignty and limiting its diplomatic space on the international stage.
The delicate nature of Taiwan’s position is evident in its careful balancing act between China and the United States. Taiwan’s president, William Lai Ching-te, has publicly called for regional peace, asserting that Taiwan and China "are not subordinate to each other."[15] However, this stance has been condemned by Chinese state media as provocative, triggering a series of aggressive military responses, including record numbers of Chinese aircraft and warships encircling Taiwan during military drills. At the same time, Taiwan has strengthened its military capabilities, increasing its defense budget by 7.7% in 2024 to deter Chinese encroachment.[16] Taiwan is acutely aware that China's growing assertiveness—evidenced by record incursions into its airspace and repeated naval activities near its outlying islands—poses a significant threat. In 2024 alone, Taiwan recorded over 2,000 Chinese military aircraft entering its Air Defense Identification Zone, the highest annual number of incursions to date, while Taiwan’s infrastructure has faced more than 90,000 cyberattacks.[17] Taiwan’s dual strategy of emphasizing diplomacy while bolstering defense reflects its ongoing struggle to safeguard its sovereignty against mounting Chinese pressure. As Taiwan strengthens defense ties with the United States in response to China’s growing assertiveness, it risks escalating tensions with Beijing, which views such cooperation as a direct challenge to its One-China policy and regional dominance. Taiwan’s experience underscores the broader challenges faced by smaller nations in the region—how to assert territorial claims and sovereignty while navigating the competing interests of larger powers, which often destabilize efforts to resolve disputes.
The U.S. approach to the South China Sea—marked by its symbolic Freedom of Navigation Operations (FONOPs) and strategic ambiguity—reveals deep contradictions in its foreign policy, raising doubts about the effectiveness of its efforts to establish a cohesive, rules-based order in the region. While Washington consistently champions the principles of freedom of navigation and international law, its actions have often fallen short of deterring China’s aggressive territorial expansion and militarization of the South China Sea.[18]Although the U.S. conducts FONOPs to assert international rights to freely navigate the seas, these operations have had little impact on curbing China’s assertiveness. This limited response, compounded by the U.S.’s refusal to ratify the United Nations Convention on the Law of the Sea (UNCLOS), weakens its credibility as a champion of international law. The lack of meaningful action—particularly the inability to effectively counter China’s growing influence—highlights a broader failure to achieve stability and cooperation in the region. What is clear, however, is that the U.S. views the destabilization of the South China Sea as a global concern, not merely a regional issue, as evidenced by its pursuit of strategic alliances. Alliances like the Quad (U.S., Japan, India, and Australia) and AUKUS (Australia, U.K., and the U.S.) offer key advantages, such as bolstered maritime security and enhanced intelligence-sharing capabilities, which serve to strengthen regional deterrence against Chinese aggression.[19] However, these alliances also face significant challenges, including divergent national interests and concerns about escalating tensions with China, which may limit their overall effectiveness in fostering long-term stability and resolving conflicts.
Further complicating the situation is the shifting and often contradictory role of the U.S. in relation to its regional allies, especially the Philippines. Despite the mutual defense obligations outlined in the U.S.-Philippines Mutual Defense Treaty, the U.S. failed to intervene during the 2012 Scarborough Shoal standoff, leaving Manila vulnerable to China’s territorial encroachments.[20] This inaction—coupled with the broader perception of U.S. commitments as unreliable—has eroded trust among Southeast Asian nations, forcing them to navigate an increasingly complex and unpredictable geopolitical landscape. The Philippines, in particular, has felt the weight of this uncertainty. While the U.S. has extended support during more recent confrontations in the South China Sea, Manila has frequently declined assistance, opting instead to handle operations independently and exhaust all other options before seeking external help.[21] This reluctance reflects a broader lack of confidence in U.S. reliability. In my view, this absence of consistent and dependable support from the U.S. is a critical reason why smaller states like the Philippines, Taiwan, and Vietnam struggle to assert their territorial claims against China. These nations find themselves caught in a strategic bind, where they must choose between aligning with a U.S. that may not act in their defense or risking direct Chinese retaliation. The U.S.'s inconsistent posture not only undermines its role as a regional security guarantor but also exacerbates regional fragmentation, making it more difficult to resolve South China Sea disputes through diplomacy or international law. In this context, the U.S.'s failure to take a firm and consistent stance further complicates the broader effort to establish a stable, rules-based order in the region.
Ultimately, the U.S.'s actions—and its failure to take decisive and consistent steps—underscore a broader challenge in the geopolitics of the South China Sea: the competing interests of multiple stakeholders, especially the U.S. and China, make it nearly impossible to establish a unified, rules-based order in the region. The reelection of President-elect Donald Trump in 2024 could further destabilize the South China Sea, as his isolationist "America First" policies would likely deepen existing divisions. Trump's preference for bilateral agreements over multilateral cooperation, combined with his economic protectionism—including tariffs on China—could lead to a reduced U.S. military presence and a retreat from security commitments in the Indo-Pacific.[22] This shift would leave countries like the Philippines, Taiwan, and Vietnam more exposed to Chinese assertiveness, while his confrontational stance on China might provoke even more aggressive actions from Beijing. Trump's policies could undermine any effort to establish a cohesive, rules-based order in the South China Sea, exacerbating regional instability and complicating diplomatic efforts to resolve ongoing disputes. Faced with this geopolitical uncertainty, Southeast Asian nations may be forced to choose between aligning with the U.S. or China, further fragmenting the region.
[1] Rongxing Guo, “South China Sea: Border, Boundary and Frontier,” ScienceDirect Topics, 2018, https://www.sciencedirect.com/topics/engineering/south-china-sea.
[2] Oleksandra Mamchii, “Strategic Importance of the South China Sea,” Best Diplomats | Diplomatic Conferences | New York, March 28, 2024, https://bestdiplomats.org/why-is-the-south-china-sea-important/#:~:text=The%20South%20China%20Sea%20has,%2C%20Chinese%2C%20and%20Indian%20civilizations.
[3] Dung Huynh, “How Weaker Nations Confront Chinese Coercion in the South China Sea,” Facing the Ravenous Sea Dragon, 2022, https://www.rand.org/content/dam/rand/pubs/rgs_dissertations/RGSDA2400/RGSDA2470-1/RAND_RGSDA2470-1.pdf.
[4] Phuong Nguyen, “The South China Sea Disputes and the Evolution of the Vietnam-China Relationship,” in Encounters and Escalation in the Indo-Pacific, May 2024, https://www.nbr.org/wp-content/uploads/pdfs/publications/sr108_encounters_and_escalation_may2024.pdf.
[5] “Hanoi in High Gear: Vietnam’s Spratly Expansion Accelerates,” Asia Maritime Transparency Initiative, June 7, 2024, https://amti.csis.org/hanoi-in-high-gear-vietnams-spratly-expansion-accelerates/.
[6] “Fact Sheet: President Joseph R. Biden and General Secretary Nguyen Phu Trong Announce the U.S.-Vietnam Comprehensive Strategic Partnership,” The White House, September 11, 2023, https://www.whitehouse.gov/briefing-room/statements-releases/2023/09/10/fact-sheet-president-joseph-r-biden-and-general-secretary-nguyen-phu-trong-announce-the-u-s-vietnam-comprehensive-strategic-partnership/.
[7] “Why Is Vietnam Rapidly Building on South China Sea Reefs?” Chatham House, October 15, 2024, https://www.chathamhouse.org/publications/the-world-today/2024-09/why-vietnam-rapidly-building-south-china-sea-reefs.
[8] “Vietnam Tacks Between Cooperation and Struggle in the South China Sea,” International Crisis Group, December 2021, https://www.crisisgroup.org/asia/north-east-asia/china/318-vietnam-tacks-between-cooperation-and-struggle-south-china-sea.
[9] Liam Reeves, “The South China Sea Disputes: Territorial and Maritime Differences Between the Philippines and China,” Journal of Global Faultlines 6, no. 1 (2019): 39–61, https://doi.org/10.13169/jglobfaul.6.1.0039.
[10] Tongfi Kim, “Sino-Philippine Disputes and the US-Philippines Alliance,” US Alliance Obligations in the Disputes in the East and South China Seas: Issues of Applicability and Interpretations, Peace Research Institute Frankfurt, 2016, http://www.jstor.org/stable/resrep14540.5.
[11] Maria Ortuoste, “The Philippines in the South China Sea: Out of Time, Out of Options?” Southeast Asian Affairs (2013): 240–53, http://www.jstor.org/stable/23471147.
[12] Abigail McGowan and Joshua Kurlantzick, “Why Tensions in the South China Sea Are Bolstering the U.S.-Philippines Alliance,” Council on Foreign Relations, September 2024, https://www.cfr.org/expert-brief/why-tensions-south-china-sea-are-bolstering-us-philippines-alliance.
[13] Dennis Hickey, “In the Eye of the Typhoon: Taiwan and the Growing Dispute in the South China Sea,” Asian Perspective 40, no. 4 (2016): 731–51, http://www.jstor.org/stable/44074805.
[14] Jennifer Chang, “Taiwan’s Delicate Balancing Act in the South China Sea,” Global Taiwan Institute, September 8, 2022, https://globaltaiwan.org/2020/07/taiwans-delicate-balancing-act-in-the-south-china-sea/.
[15] The Widening Schism Across the Taiwan Strait, September 2024. https://www.crisisgroup.org/asia/north-east-asia/taiwan-strait-china/342-widening-schism-across-taiwan-strait.
[16] John Dotson, “Taiwan Announces an Increased Defense Budget for 2024,” Global Taiwan Institute, September 21, 2023, https://globaltaiwan.org/2023/09/taiwan-announces-an-increased-defense-budget-for-2024/.
[17] Naiyu Kuo, “China Responds to Taiwan’s Plea for Cross-Strait Peace with Military Pressure,” United States Institute of Peace, October 24, 2024, https://www.usip.org/publications/2024/10/china-responds-taiwans-plea-cross-strait-peace-military-pressure.
[18] Phuong Nguyen, “Deciphering the Shift in America’s South China Sea Policy,” Contemporary Southeast Asia 38, no. 3 (2016): 389–421, http://www.jstor.org/stable/24916764.
[19] Oriana Skylar Mastro, “Deterrence in the Indo-Pacific,” Asia Policy 17, no. 4 (2022): 8–18, https://doi.org/https://www.jstor.org/stable/27254588.
[20] Suisheng Zhao, “East Asian Disorder: China and the South China Sea Disputes,” Asian Survey 60, no. 3 (2020): 490–509, https://www.jstor.org/stable/48735731.
[21] Karen Lema, “Exclusive: Philippines Turned down US Help amid South China Sea Tensions - Military Chief,” Reuters, July 2024, https://www.reuters.com/world/asia-pacific/philippines-turned-down-us-help-amid-south-china-sea-tensions-military-chief-2024-07-05/.
[22] Mely Anthony, “Why the U.S. Presidential Election Matters for the Indo-Pacific,” Council on Foreign Relations, September 2024, https://www.cfr.org/councilofcouncils/global-memos/why-us-presidential-election-matters-indo-pacific.
