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In February, South Korea’s navy took a significant step, inaugurating a task fleet command at its Jeju naval base. This development, though years in the making, didn’t go unnoticed by domestic and foreign media, and it certainly caught the attention of the Chinese military’s official media. The idea, first floated 36 years ago, has now materialized at the strategically vital Jeju naval base, which itself opened in 2016 with the 7th Task Flotilla as its backbone.

This is a major muscle move that enhances South Korea’s ability to protect its sea lanes and ensure freedom of navigation. This development is viewed by China as a significant threat to its regional security interests and ambitions, particularly concerning access to critical waterways and its plans for Taiwan, likely prompting countermeasures from Beijing. Indeed, China has never been subtle about its disapproval of the Jeju base and its growing fleet, viewing it as a mounting strategic threat, particularly if leveraged in combined operations by the U.S. and South Korean navies.

Seoul and Washington should cooperate to bolster allied naval presence near Jeju and enhance South Korea’s naval capabilities, particularly through the acquisition of nuclear-powered submarines. South Korea should also expand multilateral cooperation with Japan, Australia, and the Philippines to improve collective security and operational effectiveness in the region.

Why Jeju Matters: Securing Korea’s Lifelines

Early in its history, the South Korean navy focused on coastal defense, primarily against North Korea. However, South Korea’s phenomenal export-driven economic growth since the late 1970s — and its near-total reliance on Middle Eastern oil imports — have made the protection of sea lines of communication an overriding economic and security imperative. For decades, the South Korean navy has envisioned a fleet to protect these southern sea lanes of communications, with Jeju Island long identified as the optimal location.

Jeju’s strategic value is undeniable. Located off the peninsula’s southern coast, it sits at a critical juncture at the northern center of the First Island Chain. Its proximity to major Chinese coastal cities like Shanghai, Qingdao, and Dalian amplifies its importance as a hub for maritime surveillance and regional power projection.

The base can accommodate up to 20 warships, including Aegis-equipped destroyers, amphibious assault ships, and submarines. With the new Task Fleet Command, Seoul is clearly signaling its intent to deploy high-value naval assets to safeguard its sea lanes of communications and enhance deterrence in the East China Sea. This move aligns South Korea more closely with efforts aimed at ensuring freedom of navigation against a backdrop of China’s increasing maritime assertiveness.

Since Xi Jinping’s ascent in 2012, the world has witnessed China’s naval buildup, its aggressive militarization of the South China Sea, and its dominance in the Yellow Sea — all of which pose a direct security threat to South Korea and challenge the established maritime order. Beijing appears determined to transform its surrounding waters into virtual internal seas.

Politics and Opposition

The Jeju naval base project experienced significant delays due to strong opposition from local residents, who were concerned about potential damage to Jeju’s identity as a “peace island” and the increased security risks the base could pose in the event of war. This resistance was further amplified by the involvement of various South Korean interest groups, including prominent human rights organizations, religious groups such as the Catholic Church, and international non-governmental organizations.

Their participation led to the development of a sustained and well-organized opposition movement. Political parties — particularly those on the progressive side — responded cautiously, often prioritizing local voter support over actively promoting the project. As a result, construction, which began in 2007, was not completed until 2016.

Despite political divisions, there has been consistent bipartisan consensus on the strategic necessity of the Jeju base to enhance national security. Successive South Korean presidents — from both liberal and conservative parties — have supported the project. For example, the liberal Moon Jae-in administration, which was often seen as more accommodating to Pyongyang and Beijing, hosted the International Fleet Review at the base in 2018. The USS Ronald Reagan, a state-of-the-art U.S. aircraft carrier, participated in the event and became the first U.S. aircraft carrier to dock at the base. On the other hand, the Lee Jae-myung administration, inaugurated in June 2025, has adopted a pragmatic foreign policy based on national interests and the South Korean-U.S. alliance. As of July, key foreign and security positions — including the national security adviser, foreign minister, and defense minister — are being filled primarily by career experts rather than figures from the ruling party. Once these appointments are finalized, any shifts in the administration’s stance on the South Korean-U.S. alliance and related issues will be closely monitored.

Although there is still domestic opposition, it is on a smaller scale and has largely lost momentum. Overall, the case of the Jeju naval base offers an important policy lesson: Meaningful engagement with local communities is essential when planning and implementing national defense infrastructure projects.

Beijing’s View

Chinese commentators have scrutinized the Jeju naval base since its construction began, focusing on two main strategic implications.

First is the perceived threat from Jeju’s geography. Positioned at the northern center of the First Island Chain, it effectively controls access to critical Chinese cities like Shanghai, Dalian, and Qingdao. More than just a maritime chokepoint, Jeju is a strategic hub for sea and air routes. Beijing worries that Jeju could become another Okinawa or Yokosuka — a forward base for U.S. forces, posing a serious challenge under China’s containment narrative. This isn’t mere paranoia. South Korea’s task fleet at Jeju potentially threatens Beijing itself, which lies near the Yellow Sea’s far end — Jeju is the gateway to the Yellow Sea and, by extension, to the Chinese capital. The Jeju base also poses a strategic challenge to China’s Northern Fleet, based in Qingdao. This fleet’s primary mission is to defend Beijing and maintain maritime control over the entire Yellow Sea. Given its geographic location and the advanced combat capabilities of the Aegis-equipped warships stationed there, the Jeju base and its task fleet challenge the Northern Fleet’s efforts to assert dominance in these waters. This resonates with historical fears: the “century of humiliation” often invoked by the Chinese Communist Party began with foreign invasions via the Yellow Sea in the mid-19th century, leading to the sacking of Beijing.

Second is the implication for China’s ambition to seize Taiwan. Securing the Jeju area would be a precondition for any successful military assault on Taiwan. Given Taiwan’s geographic position — exposed on all four fronts — the northern axis, linked to the Okinawa island chain and the East China Sea, represents its most vulnerable corridor. In this theater, China would likely encounter strong resistance from U.S. and Japanese naval forces. With Jeju at the East China Sea’s northern edge, China must dominate this area to prevent interference with its Taiwan plans. Otherwise, a hostile fleet operating from Jeju would force China to fight on two fronts, diverting critical resources from a Taiwan campaign. Thus, just as U.S.-Chinese competition intensifies, the Jeju naval base and its task fleet present Beijing with a new, unwelcome strategic headache.

How Will China React? Expect More Than Just Words

With South Korea finally establishing the Jeju naval base and its task fleet, Beijing’s response is a critical question. Several reactions can be anticipated:

First, China will spare no effort to prevent the Jeju base from becoming a lynchpin of the U.S.-South Korean alliance. This means actively working to undermine the alliance’s strength, potentially by trying to manipulate the Trump administration. Expect North Korean provocations to coincide with any allied exercises based at Jeju. Furthermore, China will likely employ its “three warfares” (legal, psychological, and public opinion) to sway South Korean domestic opinion, which has seen strong opposition to the base since its inception.

Second, China will almost certainly intensify its naval and maritime activities in the Yellow Sea and the waters near Jeju to assert its control. Beijing views these as critical regions in the northern First Island Chain. To consolidate its dominance, expect increased Chinese military air and sea patrols, alongside an expansion of non-military activities like fishing operations. For instance, China has unilaterally installed large buoys in the Yellow Sea’s provisional measures zone without South Korean consent and recently constructed a massive artificial fishing facility the size of a football field, again without consulting Seoul, ratcheting up diplomatic tensions. In addition, recently, two Chinese individuals studying in South Korea were arrested by police on suspicion of espionage after unlawfully filming a military installation. They are accused of using drones and cameras to capture images of the Busan Naval Operations Command, a restricted area where photography is prohibited. These incidents have raised concerns within South Korea about potential links between the students’ activities and the Chinese government, possibly as part of gray-zone tactics.

Policy Prescriptions: Bolstering Deterrence and Cooperation

For South Korea, the secure use of the Indo-Pacific maritime domain is non-negotiable, underpinning both national security and economic prosperity. Seoul’s support for the U.S. Indo-Pacific strategy reflects this reality, a perspective shared by many regional powers like Japan, Australia, and the Philippines. Crucially, Seoul opposes any unilateral attempts, by Beijing or others, to restrict existing maritime freedoms. The Jeju naval base and its task fleet are vital assets for these national interests and for achieving the objectives of a free and open Indo-Pacific. With this in mind, several policy actions are imperative:

Increase Allied Naval Presence

The U.S. Navy, in concert with the South Korean navy, should conduct more frequent operations near Jeju. This would bolster conventional deterrence and provide a critical readiness advantage during crises. Participation should also be expanded to include allied nations like Japan, Australia, and the Philippines who share common strategic objectives. Washington should also empower Seoul to take a leading role in combined operations in this region, fostering burden-sharing. The Jeju naval base can serve as a crucial logistical hub for these allied operations.

Enhance the Task Fleet’s Capabilities

The United States has a key role to play here. The current fleet primarily comprises Dokdo-class amphibious assault ships, Aegis destroyers, diesel-powered submarines, and support vessels. Washington should endorse and facilitate South Korea’s acquisition of nuclear-powered submarines, similar to the AUKUS arrangement with Australia. A submarine’s lethality depends heavily on its stealth, which is maximized by remaining submerged for extended periods. Nuclear-powered submarines, unlike their diesel-powered counterparts, can stay underwater far longer without surfacing, granting them unmatched stealth and endurance. This fundamental advantage makes nuclear-powered submarines vastly superior in both survivability and operational reach. Such capabilities would not only overcome the inherent limitations of diesel boats but also mitigate the threat from China’s anti-ship ballistic missiles. Deploying South Korean nuclear-powered submarines to the Jeju task fleet would, as other analysts concur, present a formidable deterrent against any power seeking to disrupt the maritime order.

Strengthen Multilateral Indo-Pacific Cooperation

This is paramount. Beyond U.S.-South Korean bilateral efforts, collaborative frameworks with allies like Japan, Australia, and the Philippines should be expanded to boost collective security and operational synergy. Integrating allied naval forces and resources will significantly enhance the region’s capacity to deter and respond to threats. Joint training exercises and shared logistical facilities are also vital for fostering dialogue, improving interoperability, and reinforcing a shared commitment to a free and open Indo-Pacific. Various formats of multinational naval exercises are feasible, ranging from simple operations such as search and rescue to more complex missions like missile defense. In such scenarios, the Jeju task fleet could play several critical roles, while the Jeju naval base would serve as a key logistics hub supporting participating forces.

Joshua NamTae Park, Ph.D., is a retired South Korean naval officer and an affiliate faculty member at the Schar School of Policy and Government, George Mason University.

Image: Nathan Burke via DVIDS