This study aims to systematically analyze the operational mechanisms and outcome conditions of China’s maritime coercive diplomacy (MCD) as it has unfolded in the South China Sea since the 2010s. Traditionally perceived as a continental power, China...
This study aims to systematically analyze the operational mechanisms and outcome conditions of China’s maritime coercive diplomacy (MCD) as it has unfolded in the South China Sea since the 2010s. Traditionally perceived as a continental power, China has significantly expanded its strategic attention to the maritime domain following the Reform and Opening period, driven by rapid economic growth and expanding external trade. In this context, the maritime domain has increasingly been recognized as a core strategic space essential to national survival and prosperity. In particular, the South China Sea has been redefined as a critical arena directly linked to China’s economic security through sea lines of communication (SLOCs) and access to maritime resources, while simultaneously being perceived as a strategically vulnerable space through which neighboring states and external great powers could approach China’s strategic core.
Against this backdrop, the South China Sea has emerged as the central axis capable of materially sustaining China’s ambition to become a maritime power and to advance the maritime component of the Belt and Road Initiative (BRI). Accordingly, sovereignty over maritime features and jurisdictional rights in the South China Sea have been elevated to the status of non-negotiable core national interests. This shift in strategic perception has led to a structural transformation in China’s maritime policies and strategies. China moved beyond a passive, coastal-defense–oriented maritime posture and adopted a combined strategy of near-seas defense and far-seas protection, rapidly expanding its maritime capabilities. Alongside naval modernization, the expansion and consolidation of the China Coast Guard and the institutionalization of maritime militia forces provided China with the capacity to employ military and non-military instruments in parallel.
Following the 18th Party Congress in 2012, the goal of building China into a “maritime power” was officially institutionalized as a national development strategy, transforming maritime strategy from a conceptual vision into a policy-driven and action-oriented framework. This strategic acceleration coincided with changes in the international environment after the 2008 global financial crisis, which weakened the relative position of the United States and contributed to a perceived reduction in U.S. external intervention. China interpreted this shift as a window of strategic opportunity and moved away from the cautious foreign policy posture symbolized by taoguang yanghui toward a more assertive strategy emphasizing the active defense of maritime rights and interests.
Despite its growing capabilities, China did not rely on the large-scale use of military force to achieve its objectives in the South China Sea. Direct military confrontation risked triggering U.S. intervention and strengthening regional alignment against China. Instead, China adopted a strategy of maritime coercive diplomacy that combines naval forces, coast guard units, maritime militia, and economic and diplomatic pressure instruments. This approach allows China to manage disputes at a low level of intensity while incrementally consolidating de facto control through the accumulation of faits accomplis. Maritime coercive diplomacy thus functions as a cost-effective tool that constrains the policy choices of target states and induces behavioral change while avoiding high-cost, high-risk military conflict.
China’s maritime coercive diplomacy first intensified in the South China Sea and has since expanded to the East China Sea and waters surrounding the Korean Peninsula. This pattern suggests that China’s use of maritime coercion is not a temporary or region-specific tactic but rather a long-term, repeatable strategy. Such developments carry direct security and policy implications for South Korea, underscoring the need to accurately diagnose the nature of China’s maritime coercive diplomacy and to formulate response strategies suited to Korea’s strategic environment.
Based on this problem awareness, this study seeks to explain how China’s maritime coercive diplomacy operates and under what conditions it succeeds or encounters constraints. Three core research questions guide the analysis: First, with what intentions and through what mechanisms does China implement maritime coercion? Second, why do similar coercive instruments produce divergent outcomes across cases? Third, how are the effects of China’s coercion shaped by the interaction among the target state’s level of resistance, the structural environment of the dispute, and the involvement of external great powers?
Drawing on coercive diplomacy theory, this study constructs an analytical framework that conceptualizes China’s maritime coercive diplomacy as a process of strategic interaction among the coercing state, the coerced state, and external great powers. Three hypotheses are tested. First, China’s use of maritime military power, coast guard and militia forces, and economic pressure is likely to induce policy change by targeting the core pressure points of the opposing state. Second, the stronger the target state’s willingness to employ military force and the political resolve of its leadership, the higher the likelihood that China’s maritime coercive diplomacy will fail. Third, when external great powers—particularly the United States—do not actively intervene, China’s maritime coercive diplomacy is more likely to succeed in altering the status quo and consolidating faits accomplis.
To test these hypotheses, China is treated as the coercing state, while Vietnam and the Philippines are analyzed as target states. Four representative maritime dispute cases in the South China Sea are selected for in-depth analysis. Through comparative examination of China’s coercive mechanisms, the target states’ resistance strategies, and the level of U.S. involvement, this study empirically identifies the mechanisms and conditions under which China’s maritime coercive diplomacy produces varying outcomes.
The case analyses demonstrate that China’s maritime coercive diplomacy does not operate as a uniform, one-directional mechanism. Rather, it is a conditional strategy whose effectiveness varies significantly depending on the target state’s resistance, the institutional and strategic environment of the dispute, and the level of U.S. involvement. In the 2012 Scarborough Shoal incident, China succeeded in consolidating de facto control due to the Philippines’ limited naval and coast guard capabilities, weak political resolve, and the United States’ restrained response. In contrast, in the Second Thomas Shoal case, sustained Philippine resistance, the maintenance of a symbolic military presence, and active U.S. involvement prevented China from achieving a change in the status quo, resulting in prolonged stalemate. Similarly, in the Vietnam cases, despite the use of comparable coercive instruments, China achieved only partial or constrained outcomes due to Vietnam’s relatively strong military foundation, firm political resolve, and active diplomatic engagement supported by U.S. involvement.
These comparative findings empirically demonstrate that the effectiveness of China’s maritime coercive diplomacy is determined less by the intensity or frequency of coercive tools themselves than by the strategic interaction structure formed between coercion and resistance. Building on these findings, this study refines the theoretical understanding of maritime coercive diplomacy and assesses that China is likely to continue and expand its strategy of incremental status quo change while avoiding direct military confrontation. At the same time, the study confirms that such a strategy is subject to structural constraints imposed by the target state’s resistance and the level of engagement by external great powers.
The findings offer important policy implications for South Korea’s maritime security. China’s maritime coercive diplomacy may unfold in similar forms in waters surrounding the Korean Peninsula. Effective responses therefore require not only military capability enhancement but also the integrated employment of naval, coast guard, and law-enforcement capacities; the clear signaling of political resolve at the early stages of disputes; and the construction of credible deterrence structures through strategic coordination with the United States and allied partners. Furthermore, South Korea must adopt a multi-layered strategy that combines legal and diplomatic measures with on-site control capabilities to prevent the accumulation of low-intensity coercion from evolving into irreversible faits accomplis. In this respect, this study contributes both academically and practically by clarifying the nature of China’s maritime coercive diplomacy and providing strategic guidance for potential future coercive scenarios facing South Korea.