“China’s Installation of Structures in the West Sea: Intentions and Tasks for Korea’s Response”

Suh Sang-mun,

Director, East Sea Rim Future Research Institute

                                                       < Contents >

1. The Government’s Overly Complacent Response to China’s Infringement on Maritime Sovereignty

2. China’s Structures Violate the Korea-China Fisheries Agreement and International Law

3. The Government’s Silence Is the Bigger Problem

4. China’s Strategic Intent Behind Its West Sea Structures

5. Tasks for the Korean Government Going Forward

1. The Government’s Overly Complacent Response to China’s Infringement on Maritime Sovereignty

 How should we remove the illegal structures “Shenlan No. 1 and No. 2” and the central management platform “Atlantic Amsterdam” that China has installed without authorization in the Korea-China Provisional Measures Zone (PMZ) overlapping the two countries’ Exclusive Economic Zones (EEZs) in the West Sea in 2018 and 2024? Between 2018 and 2023, China additionally installed at least 13 lighthouse-shaped solar-powered buoys throughout the West Sea. This behavior heightens concerns about the expansion of semi-permanent maritime infrastructure across disputed waters and demonstrates China’s disregard toward our government.

 Resolving the issue of dismantling these structures cannot be done through the weak and conciliatory approach taken thus far by the Korean government. The reason both sides have remained at an impasse is not because of differences in legal interpretation under international law but because the matter is fundamentally political. The current Lee Jae-myung government, “temporarily” holding the highest position of state authority, lacks the will to defend maritime sovereignty. Instead of repeating abstract principles, the government should adopt proportional and reciprocal measures such as installing the same type of structures in the same waters to counter China in the manner that China itself is employing.

 During the 3rd Korea-China Maritime Cooperation Dialogue in April 2025 and several other meetings, Korea demanded the “removal of the Chinese structures” and their “relocation outside the PMZ.” China, however, claimed the structures were “private aquaculture facilities” beyond its government’s authority, blocking agreement. The only achievement was a verbal remark (not even a promise) from Chinese delegates that no additional structures would be installed. This indicates not a difference in legal interpretation but multilayered disputes involving maritime rights and potential sovereignty claims.

2. China’s Structures Violate the Korea?China Fisheries Agreement and International Law

 China insists the structures are purely civilian “fishing and aquaculture facilities” unrelated to territorial expansion or maritime boundary delimitation. For instance, “Shenlan No. 2” is described as a deep-sea smart aquaculture cage built by the private “Shandong Marine Group,” needed for large-scale farming of cold-water species. China argues the facilities do not violate the bilateral fisheries agreement, nor do they harm Korea’s maritime rights, and claims that while no additional facilities will be added for now, existing ones cannot be removed because they are privately built.

 The Korean government, viewing this as China’s unilateral maritime occupation with potential to be exploited as grounds for future maritime boundary claims, has asserted that all structures were illegally installed in the PMZ under the Korea-China Fisheries Agreement and UNCLOS. Korea demanded that all structures be moved outside the PMZ and warned that Korea may pursue proportional countermeasures, including installing structures of comparable scale.

 Under the 2001 Korea-China Fisheries Agreement, the PMZ is a joint management area for fisheries only. The installation of structures or marine scientific research and development activities is not allowed. Measures for fisheries management or environmental protection also require mutual consent. Thus, China’s unilateral installation is a clear treaty violation. Artificial islands or installations can only be built within a coastal state's own EEZ. Unilateral structures in the overlapping EEZ hinder the other state’s sovereign rights, including resource surveys and environmental assessments.

3. The Government’s Silence Is the Bigger Problem

 Given that China views the West Sea as a strategic hub in the context of intensifying U.S.-China rivalry, this issue cannot be resolved by working-level negotiations alone. Such disputes typically require top-level political intervention. But President Xi Jinping is unlikely to engage directly, as China is the party responsible for creating the problem.

 President Lee Jae-myung, however, verbally attacks Korean youth protesting against China calling their demonstrations “gangster antics” yet he avoids addressing China’s violations of Korea’s national interest. During the recent bilateral summit, Lee failed to secure even the lifting of the THAAD-related Korean Wave restrictions, took no action on the urgent issue of visa-free Chinese entry into Korea, and merely reiterated the vague principle of “working-level communication” regarding the illegal structures. He exchanged gifts with Xi but achieved nothing substantive what he calls “careful, detailed communication,” but in reality an empty performance.

 China continues encroaching into our maritime backyard, yet Korea’s leadership looks away. A summit that fails to address urgent bilateral disputes reveals that Lee’s “pragmatic, national-interest diplomacy” is merely rhetoric. Without strong political will at the top, confidence in the government’s ability or sincerity to pursue international legal countermeasures is inevitably questioned. One wonders if Lee even understands the implications of these structures.

4. China’s Strategic Intent Behind Its West Sea Structures

 Contrary to China’s official explanations, these installations reflect multifaceted strategic objectives. Considering the scale and capability of the structures, their sensitive locations, China’s military and paramilitary activity surrounding them, and the broader U.S.-China rivalry, the intent is far more complex.

 China is pursuing a path toward becoming a maritime great power and achieving regional hegemony. From this perspective, the West Sea structures must be seen as part of a continuum with China’s activities in the South and East China Seas. China expects Korea to side with the United States in any major crisis; therefore, it seeks to secure advantageous positions in the West Sea in advance, preparing for contingencies. These efforts reflect China’s “unrestricted warfare” strategy, which it has been deploying globally. China lists Korea, along with the U.S. and Japan, as a top-priority target.

 China has two types of border regions: areas where it prefers to maintain the status quo, and areas where it seeks to change it. The South China Sea where China built and militarized seven artificial islands is the latter. Other contested regions include the China-India border, the Taiwan Strait, the Senkaku Islands, Socotra Rock (Ieodo), and now the West Sea. China appears to have intended to incrementally expand installations in the West Sea, as it did in the South China Sea, to later use them as evidence of “effective control.” However, satellite images first obtained by Ray Powell of Stanford’s SeaLight Initiative exposed these activities.

 China has also secretly deployed at least 12 oil and gas vessels in the Taiwan Strait EEZ since July-August, installing structures and conducting drilling operations covertly.

 China’s West Sea structures are linked to the Ieodo issue. By altering the balance of influence in waters around Ieodo, which Korea effectively administers, China seeks long-term strategic advantage. By establishing structures in the PMZ where such installations are prohibited China attempts to create faits accomplis that could strengthen its position in future EEZ boundary negotiations. In other words, this is a form of “staking a claim.”

 Some analysts, including those cited by Japan’s President Online, describe these structures as “silent invasions,” functioning effectively as small artificial islands. They represent an extension of China’s gray-zone strategy.

 The structures have significant dual-use military potential. The central platform, “Atlantic Amsterdam,” includes a helipad, large communication antennas, and accommodations for over 100 personnel far exceeding what is needed for aquaculture. As in the South China Sea, civilian-use structures can later be converted for military purposes. In a contingency, these platforms could be used for maritime operations support, intelligence gathering, surveillance, and reconnaissance (ISR).

5. Tasks for the Korean Government Going Forward

 In future legal and diplomatic battles, Korea should focus on exposing inconsistencies and falsehoods in China’s claims.

(1) Question China’s Claims About Lack of Territorial Intent

 China claims the structures are movable commercial aquaculture facilities. But they are, in fact, massive steel and concrete installations weighing hundreds of tonseffectively fixed structures. Korea should challenge China directly: does it have territorial intentions in the area? Even if China denies it, its past violation of its 2015 public promise not to militarize the South China Sea proves such assurances are unreliable. China also designated multiple temporary navigation-restricted zones in the PMZ for training its newest aircraft carrier, the Fujian, in May 2025 further undermining trust.

(2) Expose China’s Claim of “Civilian, Non-Governmental Facilities” as False

 In China’s one-party system, even private enterprises must have Communist Party cells if they have at least thre e party members. No truly independent private companies exist for sensitive operations. Civilian entities can be mobilized for state purposes. Chinese purchases of islands near Okinawa or real estate in Yongsan, Seoul cannot be interpreted as private decisions; such acquisitions inevitably involve state control or direction.

(3) Highlight China’s False Promise to Allow On-Site Inspection

 China stated it would allow access to the structures. Yet in February and September 2025, when Korea’s marine survey vessel Onnuri approached Shenlan No. 2 within China’s claimed EEZ to inspect the structures, China’s Coast Guard and civilian vessels blocked the attempt, creating a two-hour standoff. This clearly shows China seeks to control the surrounding waters as if they were its own jurisdiction. Interference with the exercise of marine scientific research rights under UN Convention on the Law of the Sea is a clear international law violation.

Possible Chinese Counterstrategy

 In prolonged negotiations, China may eventually propose a conditional deal: “We will remove our structures only if Korea dismantles its facilities at Ieodo.” Korea must prepare for this. The best preemptive response is to install Korean maritime research structures of comparable type in the PMZ. The Lee Jae-myung administration should initiate this immediately.

 Vietnam’s example should be consulte since 2021 it has reclaimed and expanded 21 artificial islands in the Spratly Islands (as of March 2025), confronting China firmly. China does not challenge Vietnam aggressively because of its historical defeat during the 1979 conflict. Korea should learn from Vietnam’s strategic posture and its “bamboo diplomacy.”

This article may differ from the views of the Hansun Foundation.

(※ It's a translation based on machine translation)