The high-stakes power struggle in the South China Sea unfolds as China’s audacious ambitions collide with the Philippines’ bold resistance, bolstered by US alliances amid ASEAN’s fractured diplomacy. Beyond mere territorial disputes, it exposes a critical battleground for international law, global influence, and the shifting order of 21st-century geopolitics.

The South China Sea has long been a flashpoint for geopolitical rivalry, but 2024 has brought a sharper escalation of tensions. The region, one of the world’s busiest maritime arteries and rich in natural resources, is now witnessing more frequent and confrontational encounters among China, the Philippines, and other claimant states. These incidents are reshaping regional dynamics and testing the resilience of international norms, global alliances, and strategic calculations in the Indo-Pacific.

China’s strategic calculus: dominance through incremental gains 

China’s playbook in the South China Sea has shifted from mere assertion to active confrontation. Recent incidents, such as the August 2024 ramming of a Philippine vessel near Sabina Shoal, underline Beijing’s willingness to engage in coercive measures under the guise of protecting its “historic rights.” These actions are part of a broader strategy of “gray zone” operations, where China exploits ambiguity to achieve tactical objectives without sparking open conflict. 

What sets China’s current approach apart is not just its aggressiveness but its calculated unpredictability. By utilising maritime militia, coast guard units, and civilian vessels, Beijing not only blurs the lines of international law but also tests the resolve of smaller claimant states. This strategy is not merely defensive; it is part of China’s ambition to transform contested waters into de facto Chinese territory, backed by a militarised presence that rivals any other in the region. 

The stakes for China are not limited to territorial control but extend to the strategic leverage that dominance over the South China Sea offers. These waters are crucial not only for China’s economic lifelines but also for its broader geopolitical aspirations, which include projecting power across the Indo-Pacific and beyond. Beijing’s defiance of the 2016 South China Sea arbitral ruling is more than a legal stance; it is a statement about China’s vision of a revised regional order, one that prioritises strength over rules​.  

The Philippines: a new era of defiance 

In stark contrast to the appeasement strategies of previous administrations, the Philippines under President Ferdinand Marcos Jr. has adopted a posture of active resistance. Manila has shifted from quiet diplomacy to direct confrontation, calling out China’s actions at major international forums, including ASEAN summits. The Philippines’ response to China’s harassment—public denunciations, bolstered military deployments, joint patrols, and closer defence ties with the United States, Australia, and Japan—signals a broader recalibration of its foreign policy. This shift is not merely reactive; it is a strategic choice to counter China’s pressure through deterrence and alliances.  

Recent military drills like “Kamandag” and “Sama Sama” underscore the Philippines’ intent to build credible deterrence capabilities. With support from Washington, Manila is upgrading its naval assets and expanding its surveillance capacity. This shift is both a pragmatic response to immediate threats and a signal of the Philippines’ broader commitment to upholding international norms in contested waters​.  

Yet, the Philippines faces a delicate balancing act. While strengthening ties with the US offers security advantages, it also risks deepening economic vulnerabilities with China, its largest trading partner. This dual challenge of resisting maritime coercion while maintaining economic stability defines Manila’s current predicament. It is a gamble that aims to leverage international support while avoiding outright conflict—a gamble that could shape the region’s strategic landscape for years to come. 

The United States: balancing credibility and restraint 

For Washington, the South China Sea represents not just a series of disputes but a strategic battleground for influence in the Indo-Pacific. Recent actions, including a $500 million defence aid agreement with the Philippines, reflect a commitment to reinforcing regional partnerships. The US military presence in the region, marked by Freedom of Navigation Operations (FONOPs) and joint drills, serves both as reassurance to allies and deterrence to Chinese assertiveness.  

However, US strategy in the South China Sea is fraught with dilemmas. On the one hand, it must maintain a strong presence to uphold its credibility as a security guarantor; on the other, it must avoid actions that could escalate tensions into a broader conflict. Washington’s focus on “integrated deterrence”—a blend of military, diplomatic, and economic measures—aims to create a regional coalition capable of countering China’s coercive tactics. But this approach is not without limits. While the US seeks to rally regional partners, the effectiveness of these alliances hinges on sustained commitment and the willingness of regional states to share the risks of potential confrontation​. 

Washington’s emphasis on rules-based order and adherence to UNCLOS contrasts sharply with Beijing’s disregard for the 2016 arbitral ruling. This divergence underscores the broader ideological contest in the South China Sea: one that pits China’s revisionist ambitions against the established principles of international law. The region, therefore, becomes a critical arena where the US must not only project power but also demonstrate its capacity to uphold international norms. 

ASEAN’s challenges: between cohesion and constraints 

ASEAN’s response to the South China Sea tensions is emblematic of its broader struggle for relevance in great power competition. While some member states, like Vietnam and the Philippines, have pushed for a more assertive stance, others remain hesitant, wary of economic repercussions from China. The protracted negotiations over a Code of Conduct (CoC) reflect these divisions, revealing ASEAN’s inability to forge a unified policy amid competing national interests and external pressures.  

The CoC, which has been under negotiation for over two decades, remains more aspirational than operational. China’s economic influence over certain ASEAN members, coupled with its diplomatic leverage, has stymied progress towards a binding agreement. This impasse raises questions about ASEAN’s effectiveness as a regional mediator and its capacity to enforce stability in the South China Sea. As China continues to test ASEAN’s cohesion, the regional bloc’s relevance in shaping maritime security dynamics becomes increasingly uncertain​. 

Broader implications: a strategic litmus test for the 21st century 

The South China Sea has become more than a battleground for territorial claims; it is a microcosm of the broader strategic rivalries redefining the geopolitical order of the 21st century. As Beijing asserts its dominance over strategic waters, Manila manoeuvres to protect its sovereignty, and Washington seeks to maintain its credibility as a security guarantor—the stakes extend beyond control of a sea. This is a contest of wills, one that intertwines national identity, regional stability, and global influence. 

The inability of existing diplomatic frameworks to contain these rising tensions reveals a deeper reality: the South China Sea conflict is not simply a matter of law or policy, it is a matter of strategic perception. For China, it is about reshaping the regional order. For its neighbours, it is about resisting that change without triggering disaster. Meanwhile, ASEAN’s struggles underscore the limits of multilateral diplomacy in the face of raw power. 

If the region is to avoid slipping into crisis, the answer does not lie in rigid formulas or superficial dialogues, but in innovative diplomacy, strategic restraint, and a reinvigorated commitment to international norms. The South China Sea is not merely a maritime dispute—it is a litmus test for how the world will resolve, or fail to resolve, the complex tensions of a multipolar age.  

Dr Lowell Bautista is Associate Professor at the School of Law and the Australian National Centre for Ocean Resources and Security (ANCORS), University of Wollongong, Australia. An internationally recognized expert in the law of the sea, Dr. Bautista specializes in Asia-Pacific territorial and maritime disputes, particularly in the South China Sea, with research interests in ocean governance, maritime security, and international law.

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