Korea’s future lies at sea
Growing up in Busan, I’ve witnessed firsthand how Korea’s second-largest city serves as more than just a commercial hub. This year’s Asia-Pacific Economic Cooperation (APEC) summit brought renewed attention to the city’s diplomatic significance, as it hosted notable sideline meetings such as the summit between U.S. President Donald Trump and Chinese President Xi Jinping, as well as the final summit between President Lee Jae Myung and then-Japanese Prime Minister Shigeru Ishiba in September.
While Busan is often framed through its history of hosting major events like APEC 2005 or its symbolic status as the last defensive bastion during the 1950-53 Korean War, these explanations often miss the deeper strategic reality. Busan’s true importance lies in its position at the epicenter of Indo-Pacific maritime security, a role that reflects Korea’s identity. The Republic of Korea is, above all, a maritime nation whose prosperity and security depend significantly on the sea.
The “East-Up” map, recently presented by United States Forces Korea Commander Gen. Xavier Brunson, explains this view. Centering the Pacific Ocean rather than relegating it to the periphery, Korea is highlighted as a critical node in a dense maritime network. Surrounded by water on three sides, Korea depends on uninterrupted sea lanes for energy imports, trade flows, digital connectivity and military reinforcements.
Korea’s maritime dependence is not anomalous. Approximately 90 percent of international trade travels by sea. Nearly half the world’s population lives near coastlines, and submarine cables crisscrossing the ocean floors underpin the entire international communication network that undergirds financial markets and digital economies. When maritime order breaks down, it leads to a vicious cycle of collapsing supply chains, accelerating inflation and increased geopolitical instability.
Freedom of navigation, therefore, is more than mere rhetoric in diplomatic talking points. Open seas reduce both transaction costs and the political instability that hampers active trade relations between countries. As Sarah Paine, distinguished historian at the U.S. Naval War College, argues in a recent article for Foreign Affairs magazine, even countries like China have been among the principal beneficiaries of integration into the existing maritime order and global trading system.
However, no nation can secure the seas independently. Maritime routes are vast, interconnected and inherently vulnerable to disruption. Maritime order survives through shared rules, such as the U.N. Convention on the Law of the Sea, coordinated enforcement between countries that share stakes in the region, and coalitions between capable states.
This structural necessity explains the growing emphasis on maritime cooperation in Korea’s multilateral efforts, notably the U.S.-Korea-Japan trilateral framework. Maritime issues have figured prominently in trilateral statements following the 2023 Camp David Summit and subsequent ministerial meetings, consistently underscoring freedom of navigation, opposition to unilateral status quo changes, coast guard cooperation and maritime capacity-building in Southeast Asia — a region that shares critical maritime challenges.
This cooperation has already produced tangible results. Efforts such as the trilateral Freedom Edge exercise in September, coordinated flight escorting U.S. bombers in the Pacific and the Joint Chiefs of Staff meeting in July have contributed to enhanced interoperability and reduced miscalculation risks. Expanding coast guard cooperation, including gray-zone response and maritime search-and-rescue operations, has helped address challenges that erode regional order without triggering armed conflict and cultivate habits of cooperation that are essential for crisis management at sea.
While institutionalizing these mechanisms and increasing the frequency of joint exercises to align threat perceptions remain key challenges, the three countries are moving collectively — and decisively — in the right direction.
However, one critical dimension warrants deeper attention: where maritime security is actually lived and sustained. Port cities host the naval bases, logistics hubs, shipbuilding facilities and civilian maritime industries that make deterrence operational.
Places like Busan, Pohang and Jinhae in Korea, Maizuru and Yokosuka in Japan, and San Diego and Pearl Harbor in the United States are not merely symbolic locations, but where strategy becomes reality, where naval personnel train, where deploy supply chains converge and, ultimately, where disruptions would be felt first.
Yet trilateral cooperation remains heavily concentrated — understandably so — at the national and military-to-military levels. The gap between strategic statements and the cities shouldering maritime security responsibilities suggests an untapped opportunity.
Bringing together port cities with direct stakes in maritime readiness through regular exchanges, joint consultations, tabletop exercises and working-level coordination alongside naval and coast guard officials could deepen shared threat awareness, improve contingency planning and strengthen civil-military coordination against gray-zone activities that target civilian shipping emergency response readiness.
Such efforts would also enhance societal resilience. Maritime security encompasses more than warfighting; it also means sustaining economic life under pressure. Port authorities, local governments and civilian industries are indispensable partners, yet they remain underutilized in current trilateral frameworks.
To be sure, trilateral cooperation is not a panacea. In the maritime domain, it cannot resolve sovereignty disputes or resolve fundamental differences in how each country perceives regional actors. Political sensitivities, escalation risks and resource constraints remain real. But it can still raise the costs of coercion, preserve rules-based order and create diplomatic space for managing tensions.
For Korea, whose national lifelines traverse open waters, maritime security forms the foundation of national defense and economic resilience. If anything, escalation begins at sea before it reaches land.
Seoul has long recognized the importance of maritime security. Yet the strategic value of port cities, where the sea meets the shore, has remained underappreciated. Busan’s place in this year’s diplomatic calendar reflects a deeper reality, one that will only grow bigger in the years ahead.
Park Jin-wan is a nonresident fellow for the European Centre for North Korean Studies at the University of Vienna and co-founder of the U.S.-ROK-Japan Trilateral Next-Gen Study Group.