By James Borton and Sherry Chen
The Center for Strategic and International Studies (CSIS) convened its 15th Annual South China Sea Conference, drawing experts, officials, and scholars to dissect the region’s shifting strategic landscape. Across four panels and a keynote by Admiral Stephen “Web” Koehler, the conference addressed key issues including China’s maritime assertiveness, legal dispute mechanisms, evolving alliance frameworks, and the growing role of outside powers. Emphasizing cooperation, rule of law, and regional resilience, the event highlighted the South China Sea as both a flashpoint and a proving ground for international diplomacy and security.
Panel I Summary: States of Play in the South China Sea
The opening panel, moderated by Henrietta Levin, offered a nuanced exploration of shifting power dynamics in the South China Sea, spotlighting China’s stepped-up patrols around Scarborough Shoal, Vietnam’s silent island expansions, and the steady tempo of U.S. military exercises. Panelists highlighted growing aerial friction, Malaysia’s careful balancing act amid rising Chinese influence, and the critical role of public sentiment shaped by influence campaigns. The session underscored how military posturing, strategic narratives, and alliance recalibration are redefining the region’s fragile equilibrium—where deterrence alone is no longer enough, and diplomacy, perception, and multilateral coordination are increasingly vital.
Panel 2 Summary: Legal Developments and Dispute Management
The second panel delved into the complex legal terrain of the South China Sea, spotlighting the clash of national legislation, maritime claims, and interpretations of international law. Experts unpacked the Philippines’ recent Maritime Zones Act—an assertive move to codify the 2016 arbitral ruling—against the backdrop of China’s new baseline declarations around Scarborough Shoal. While these legal maneuvers reflect growing normative assertiveness, panelists noted they have deepened the legal stalemate, with the U.S. and China firmly at odds over the application of UNCLOS and “general international law.” Despite this, speakers called for renewed emphasis on regional cooperation, transparency initiatives, and diplomatic tools to manage tensions.
Scientific diplomacy emerged as a key theme, with panelists advocating for joint marine research, environmental data sharing, and depoliticized collaboration as pathways to de-escalation. The discussion suggested that while law remains a foundational element in dispute management, it must be paired with creative, multilateral approaches to prevent miscalculation. In a region marked by rising maritime activity and legal contestation, the panel concluded that blending legal rigor with cooperative innovation offers the best hope for sustainable peace.
Panel 3 Summary: Evolving Alliance Networks
Panel 3 focused on the shifting architecture of Indo-Pacific security, examining how regional and extra-regional powers are translating political alignment into operational deterrence. Moderator Kristi Govella set the tone by highlighting a transition from bilateral to increasingly multilateral defense frameworks, particularly involving Japan, Australia, the Philippines, and the U.S. Japan’s Kotani Tetsuo discussed Tokyo’s emerging role as a security contributor through its Official Security Assistance (OSA) program, while Dianne Despi outlined Manila’s urgent drive for defense modernization in the face of Chinese coercion. John Blaxland noted Australia’s shift toward proactive maritime deterrence, backed by high-end capabilities like nuclear-powered submarines under AUKUS, while Kathryn Paik emphasized ASEAN’s central role and the growing strategic relevance of Indonesia.
The conversation underscored the growing complexity and interdependence of alliance networks, especially as Taiwan and South China Sea contingencies increasingly overlap. Panelists agreed that future security lies in transforming policy consensus into hard capabilities: shipbuilding, maritime domain awareness, and joint exercises are no longer optional but essential. Q&A discussions highlighted Taiwan’s potential integration into regional planning, Europe’s complementary role in global security burden-sharing, and the pressing need for defense-industrial cooperation. The panel concluded that deterrence in the Indo-Pacific must now be backed by interoperability, readiness, and resilience if the regional balance is to be preserved.
Keynote: Admiral Stephen “Web” Koehler
1. Overall Summary
Admiral Stephen “Web” Koehler delivered a keynote address that underscored the strategic weight of the South China Sea in the U.S. Indo-Pacific strategy. He detailed China’s coercive behavior and the growing resilience of Southeast Asian nations, while reaffirming the centrality of deterrence and international law. The Admiral emphasized the U.S. Navy’s role—particularly the Pacific Fleet—in upholding regional order through multilateral exercises and forward presence. He also addressed future strategic priorities, such as aligning with allies, countering China’s attempts to divide the region, and enhancing maritime capabilities across partner nations. His remarks, including a robust Q&A session, conveyed both urgency and commitment in maintaining peace, stability, and freedom of navigation in the South China Sea.
2. Key Points
Strategic Significance of the South China Sea
Admiral Koehler began by outlining the geostrategic importance of the South China Sea—not just for the nations bordering it, but for global commerce and regional stability. He highlighted two major trends: growing global recognition of the region’s critical role and the increasing effectiveness of deterrence in holding back coercive behavior, particularly from China. Despite escalating maritime deployments, Koehler noted that China has failed to intimidate Southeast Asian states or sever their growing partnerships with the United States and its allies.
China’s Aggression and Southeast Asian Resilience
A central theme was China’s continued use of maritime militia, coast guard vessels, and artificial island bases to assert control over contested waters. Admiral Koehler described these tactics as coercive and unlawful under international law. Yet he praised countries like the Philippines for their resilience, citing examples where Manila resisted pressure and exposed Chinese harassment. Public transparency, he argued, plays a vital role in countering Beijing’s gray-zone operations.
U.S. Navy’s Deterrence and Regional Cooperation
Koehler detailed the U.S. Navy’s ongoing efforts to bolster deterrence and enhance regional maritime capabilities. He cited key multilateral exercises such as Malabar (with India, Australia, and Japan) and Valkyrie (with the Philippines) as demonstrations of joint readiness and interoperability. The U.S. Pacific Fleet, he explained, remains focused on maintaining combat readiness, supporting freedom of navigation, and ensuring its ability to prevail in a high-end conflict if necessary.
Balancing Global Commitments and Pacific Focus
While acknowledging America’s global military responsibilities, Admiral Koehler stressed the priority of maintaining a strong Pacific posture. He addressed concerns over resource strain, asserting that the Navy remains committed to meeting both regional and global demands. He also highlighted the role of the U.S. Coast Guard in upholding maritime law and governance, especially in training and patrolling missions with Southeast Asian partners.
China’s Base in Cambodia and Future Threats
Admiral Koehler flagged China’s naval base in Ream, Cambodia as a development of strategic concern. He warned of Beijing’s intent to project power and divide Southeast Asian countries through political and military leverage. He urged allies and partners to continue investing in their own defense capabilities while operating collectively to ensure that no single country in the region could be isolated or coerced.
Future Strategic Priorities and Expectations
Looking ahead, Admiral Koehler emphasized deterrence through presence as the guiding strategic principle. He called for increased joint training, shipbuilding collaboration, and sustained operational tempo to prepare for future contingencies. He also warned that China would likely continue efforts to pressure and divide ASEAN countries, necessitating unified messaging and stronger defense networks among U.S. allies and partners.
3. Summary of the Q&A Session and Further Insights
During the Q&A session, Admiral Koehler responded to several key questions, providing further clarity on U.S. strategy and regional coordination:
- S. Coast Guard Role: He highlighted the Coast Guard’s increasing importance in maritime law enforcement, fisheries protection, and capacity-building with smaller Southeast Asian nations.
- Cambodia’s Naval Base: On China’s facility in Cambodia, Koehler acknowledged the strategic implications and called for vigilance, asserting that such footholds could enable coercion far beyond China’s coast.
- Legal Frameworks and UNCLOS: Koehler reaffirmed the U.S. commitment to upholding international maritime law, despite the U.S. not being a signatory to UNCLOS, and emphasized its operational alignment with legal principles in practice.
- Balancing Readiness and Diplomacy: He admitted the difficulty of maintaining high readiness across global theaters but reiterated that deterrence requires sustained presence, credible combat power, and regional cooperation.
- Alliances and Messaging: In line with ongoing concerns, Koehler stressed the importance of strategic messaging and operational synchronization among the U.S., Japan, Australia, and other regional players to ensure that no Southeast Asian nation faces pressure alone.
4. Conclusion
Admiral Koehler’s keynote reinforced the message that the South China Sea is a linchpin of regional and global stability. In the face of mounting Chinese coercion, he championed the U.S. Navy’s role as both a deterrent and a partner. Through exercises, persistent presence, and joint capabilities, the Pacific Fleet aims to ensure a free and open Indo-Pacific. The Admiral’s message was clear: the U.S. will not stand alone, nor let others stand alone, in protecting the principles of sovereignty, stability, and international law in one of the world’s most contested maritime regions.
Panel 4 Summary: The Role of Outside Parties
The final panel of the conference highlighted how external actors—namely the European Union, South Korea, India, and Canada—are stepping up engagement in the South China Sea despite being non-claimant states. Panelists emphasized that these countries bring economic leverage, strategic signaling, and normative influence to a region increasingly defined by coercive behavior and legal contestation. From maritime capacity-building to supporting the 2016 arbitral ruling and backing UNCLOS, outside parties are aligning around a shared commitment to upholding international law and countering revisionist tactics. While their military presence remains limited, their contributions in training, transparency, and strategic partnerships are growing steadily.
Europe was framed as a normative power, backing the rules-based order through soft security tools and initiatives like the Coordinated Maritime Presence. South Korea’s defense diplomacy has become more assertive under President Yoon, with weapons transfers and joint exercises reflecting a shift away from strategic ambiguity. India, meanwhile, is positioning itself as a regional—not external—stakeholder, backing legal norms and selectively asserting its presence. Canada’s Indo-Pacific strategy, though modest in scale, aims to deepen coordination with like-minded democracies. Across the board, panelists stressed that while these actors may lack overwhelming force projection, their strategic convergence and focus on maritime governance, deterrence cooperation, and regional resilience are becoming indispensable to the evolving Indo-Pacific security order.
Conference Wrap-Up: Charting the Future of the South China Sea
The 15th Annual South China Sea Conference offered a sweeping assessment of the region’s rapidly shifting strategic landscape, highlighting the intensifying competition, legal contestation, and evolving alliance structures shaping one of the world’s most vital maritime corridors. Through four in-depth panels and a keynote by Admiral Stephen “Web” Koehler, experts emphasized the enduring importance of international law, the rising stakes of military deterrence, and the growing engagement of external actors from Europe to the Indo-Pacific.
Vietnam emerged as a pivotal actor throughout the discussions, often cited for its quiet but deliberate expansion of maritime capabilities and strategic outposts. While avoiding overt escalation, Vietnam continues to solidify its position through infrastructure development in the Spratlys and increasing security dialogue with regional and extra-regional partners. The conference underscored that Hanoi’s approach—combining legal alignment with UNCLOS, selective cooperation with powers like Japan and India, and a watchful stance on Chinese assertiveness—embodies the kind of calibrated resilience that smaller claimants may emulate. As great power dynamics sharpen, Vietnam’s balancing act will remain a key barometer for regional autonomy and strategic adaptability.
A clear takeaway emerged: no single nation can unilaterally secure stability in the South China Sea. Peace and order will hinge on multilateral cooperation, credible legal mechanisms, and enhanced maritime capacity across the region. With gray-zone tactics and coercive strategies on the rise, participants stressed the need for adaptive, rules-based responses anchored in transparency, alliance interoperability, and collective resilience. As geopolitical pressures mount, so too must the resolve to defend an open and lawful maritime future.
James Borton is the Editor-in-Chief of the South China Sea NewsWire and the author of Harvesting the Waves: How Blue Parks Shape Policy, Politics, and Peacebuilding in the South China Sea.
Sherry Chen is a Research Associate at South China Sea NewsWire (SCSNW), a regional news and analysis platform focused on political, economic, and strategic developments in the South China Sea, and is currently studying in a dual program between Columbia University and Sciences Po Paris.
