ED China’s illegal maritime structures in West Sea

Workers operate on a Chinese structure in the West Sea provisional maritime boundary zone, Thursday. During a National Assembly hearing, Rep. Lee Byeong-jin of the Democratic Party of Korea said this marks the first time personnel have been spotted on the structure and warned that the structure, which China claims is an aquaculture facility, could be used for military purposes. Courtesy of the office of Rep. Lee Byeong-jin

Recent revelations about Chinese activity in the Korea-China Provisional Measures Zone (PMZ) in the West Sea have reignited concerns over Beijing’s growing maritime assertiveness.

Newly released photographs show divers and maintenance personnel operating on steel structures that China installed without prior consultation — facilities Beijing claims are “deep-sea aquaculture platforms.” Yet their scale, equipment and guarded nature strongly suggest that these are not innocent fishing installations but instead are part of a broader attempt to entrench a Chinese presence in contested waters.

The PMZ was established under the 2001 Korea-China Fisheries Agreement as a temporary arrangement until the two sides negotiate a permanent maritime boundary. The agreement explicitly permits fishing activities but prohibits the construction of fixed structures. Nevertheless, China began erecting steel facilities, dubbed Shenlan 1 and Shenlan 2, in 2018 and has steadily expanded them since 2022. Korean authorities report that Chinese vessels have blocked access to the area and that Beijing unilaterally declared portions of the PMZ, including parts of Korea’s Exclusive Economic Zone (EEZ), a no-sail zone earlier this year to conduct military drills.

These actions echo China’s playbook in the South China Sea, where small installations evolved into artificial islands hosting radar systems and military airstrips. There is growing concern that Beijing is attempting to replicate this strategy in the West Sea, effectively transforming disputed maritime areas into its de facto territory. The recently revealed images — showing divers and industrial equipment rarely associated with aquaculture — only deepen suspicions that China’s real intent extends far beyond fisheries.

Despite these developments, Seoul’s response has been notably muted. The Ministry of Foreign Affairs stated that “China has explained the facilities have no military or sovereignty-related purpose” and said it was “difficult to definitively determine” whether the installations violate the fisheries agreement. This cautious language contrasts sharply with the Republic of Korea Navy chief’s remarks that China “is not complying with international law.” The mixed signals risk projecting weakness at a moment when assertiveness is essential.

The West Sea is not merely a fishing zone; it is a critical strategic buffer. The proximity of these installations to U.S. Forces Korea facilities in Pyeongtaek, Gyeonggi Province, raises legitimate security concerns. The U.S. Assistant Secretary of Defense for Indo-Pacific Affairs nominee recently warned that “China’s activities in the West Sea appear intended to intimidate South Korea.” This issue is therefore not only a bilateral dispute but also a matter of regional stability that warrants close Korea-U.S. coordination.

Korea cannot allow its maritime sovereignty to erode by degrees. The government must take principled and proportionate action grounded in international law. It should formally demand that China disclose detailed information on these structures, allow joint on-site inspections and environmental impact assessments and dismantle the installations if found to be in violation of the fisheries agreement. Should Beijing refuse, Seoul must proceed with proportional countermeasures — such as installing its own marine research platforms or navigational buoys within the PMZ — and ensure the necessary funding is restored in the national budget.

The timing of these revelations is particularly sensitive. Chinese President Xi Jinping is scheduled to visit South Korea for the Asia-Pacific Economic Cooperation (APEC) meetings, his first such visit in 11 years. While there are many topics on the bilateral agenda, this issue must not be sidestepped. President Lee Jae Myung should raise issue of the West Sea structures directly with Xi and make a clear demand for their removal. A measured but firm response will demonstrate that Seoul values dialogue but will not compromise its sovereignty.

Defending Korea's territorial waters is not an option. China’s pattern of unilateral expansion cannot be ignored or excused under the guise of diplomacy. Upholding maritime sovereignty through law, vigilance and resolve is not only a matter of national pride but a duty to future generations.