This study aims to analyze the impact of China’s maritime Grey zone strate gy on the maritime security of the Korean Peninsula and to propose effective response measures for South Korea. Since the 2000s, China has achieved rapid economic growth and ...
This study aims to analyze the impact of China’s maritime Grey zone strate gy on the maritime security of the Korean Peninsula and to propose effective response measures for South Korea. Since the 2000s, China has achieved rapid economic growth and military modernization, making the pursuit of maritime p ower a central goal of national development. Under President Xi Jinping’s lead ership, China has promoted the “Chinese Dream” and the “Belt and Road Initi ative”, while implementing a dual strategy of near-seas defense and far-seas protection to expand its influence across East Asia, including the South China Sea, East China Sea, and West Sea. As an instrument of this maritime expansi on, China has actively employed Grey zone operations, which restrict an oppo nent’s response and gradually achieve strategic objectives without crossing the threshold of armed conflict. In the South China Sea, China’s activities include island construction and mili tary base development; in the East China Sea, the ongoing Senkaku (Diaoyuda o) Islands sovereignty dispute continues; and in the West Sea, illegal structures near Ieodo and within the Korea–China Provisional Measures Zone represent n ew sources of tension. Particularly, China has utilized its maritime militia as a tool to maximize military effects through non-military means, conducting quasi -military operations disguised as civilian activities. These actions fall into a leg ally ambiguous area under international law, making them typical examples of Grey zone strategy. This study approaches the issue from both theoretical and empirical perspec tives. Drawing upon works by the RAND Corporation and the U.S. Department of Defense, it defines the theoretical concept of Grey zone strategy and identi fies its characteristics—ambiguity, asymmetry, and incrementalism—classifying it s operational tools into military, paramilitary, and non-military domains. In the maritime sphere, such activities manifest as salami-slicing and fait accompli ta ctics that incrementally erode the maritime rights and interests of other nation Based on this theoretical foundation, the study examines concrete cases of China’s maritime Grey zone activities surrounding the Korean Peninsula. First, the Ieodo dispute exemplifies China’s repeated intrusions into the Korea Air D efense Identification Zone (KADIZ) and continuous patrols by Chinese coast gu ard vessels as attempts to establish de facto control, directly affecting Korea’s maritime sovereignty and surveillance posture. Second, the illegal construction of structures within the West Sea’s provisional measures zone, disguised as me teorological buoys, reflects China’s strategic intent to internalize these waters as its “domestic sea”. Third, the maritime militia represents China’s most pract ical asymmetric tool, testing South Korea’s Navy and Coast Guard through sust ained Grey zone operations under the guise of fishing. Fourth, in the realm of undersea warfare, China’s actions—such as tapping and severing submarine co mmunication cables—pose new threats to critical information infrastructure. The study also provides a comparative analysis of the responses of Vietnam, the Philippines, and Japan. Vietnam has maintained a strong will to defend sov ereignty and garnered international support, effectively deterring China’s marit ime provocations. Conversely, the Philippines’ inadequate diplomatic response d uring the 2012 Scarborough Shoal incident resulted in territorial losses. Japan’s integrated response by the Japan Coast Guard, Self-Defense Forces, and Minis try of Foreign Affairs effectively deterred China’s maritime provocations near the Senkaku Islands, though the area has been partially transformed into a co ntested zone, marking a limited success for China. These cases demonstrate th at the success or failure of Grey zone operations depends on a nation’s whole -of-government coordination and comprehensive response capability. Building on these insights, this study proposes the following policy recommen dations for South Korea. First, South Korea must establish a national maritime security strategy that integrates diplomatic, legal, economic, and military instru ments to respond systematically from the early stages of Grey zone provocatio ns. Second, it is essential to enhance naval capabilities and strategic employme nt through improved intelligence, surveillance, and reconnaissance (ISR) system s and the development of advanced technologies such as undersea monitoring networks. Third, the Navy–Coast Guard coordination system must be strengthe ned to ensure real-time information sharing and unified command, maintaining both legal legitimacy and military deterrence. Fourth, international cooperation should be expanded by reinforcing the ROK–U.S. alliance and strengthening m ultilateral partnerships with ASEAN and other regional actors to build a multila yered maritime deterrence framework against China’s expansion. Through this analysis, the study elucidates the nature of China’s maritime G rey zone strategy and presents strategic foundations for South Korea to beco me a proactive leader in maritime security. Future research should focus on u ndersea warfare, including submarine cable protection and the deployment of unmanned underwater systems, as this domain represents the expansion of the traditional security paradigm into the undersea, information, and cyber realms. Ultimately, this study provides meaningful policy implications for safeguarding South Korea’s maritime sovereignty and promoting stability in the East Asian maritime order. Keywords : China’s Maritime Strategy, Grey Zone Strategy, South China Sea, E ast China Sea, West Sea, Ieodo, Maritime Disputes, Maritime Militi a, Undersea Warfare, South Korea’s Response