Reorganization of the Japan Maritime Self-Defense Force and the Threat of Chinese Maritime Militia: The Development of a New Gray Zone Strategy in the East China Sea

On March 24, 2026, the Japan Maritime Self-Defense Force (JMSDF) implemented a large-scale organizational restructuring by abolishing the Escort Fleet, which had been its main force since 1961, and establishing a new Surface Force. This restructuring is not merely a change of name; it signifies a significant turning point in Japan's maritime security strategy. At the same time, abnormal behavior patterns exhibited by Chinese "fishing boats" in the East China Sea have continued, and these two developments symbolize the search for a new strategic balance in the Northeast Asian maritime region.

The organizational restructuring of the JMSDF aims to expedite decision-making and enhance the efficiency of vessel operations. According to reports from Kyoto News, the four escort flotillas that were under the former Escort Fleet have been reorganized into three surface combat groups under the newly established Surface Force. Chinese military analyst Fu Qianshao has analyzed that this restructuring reflects a transition to the operation of quasi-aircraft carriers and preparations for potential conflicts with Beijing. In fact, this restructuring can be positioned as an organizational response to the maritime security challenges Japan faces, particularly in response to the intensification of China's maritime expansion.

On the other hand, organized movements of Chinese fishing fleets continue in the East China Sea. From December 24 to 26, 2025, over 2,000 Chinese fishing vessels formed a reverse L-shaped formation, aligning over a distance of 470 kilometers. Similar activities were confirmed in January and March 2026, with more than 1,000 vessels operating beyond the Japan-China median line. Most of these vessels set sail from Zhejiang Province, with 200 to 300 participating each time.

Under the Japan-China Fisheries Agreement, these activities are not illegal as long as they are considered fishing operations. However, the question arises as to why thousands of vessels repeatedly align over hundreds of kilometers. The answer to this question lies in the reality of China's maritime militia organization. Article 22 of China's National Defense Law defines the militia as part of the armed forces alongside the active-duty People's Liberation Army, reserves, and the People's Armed Police. According to Chinese sources, fishermen and crew members are subject to conscription and are usually engaged in civilian livelihoods while being mobilized to support the military or the Coast Guard as needed.

Since around 2013, when the protection of maritime interests was elevated to a central priority for the party, government, and military, pilot programs to establish maritime militia units in cities such as Ningbo, Wenzhou, and Taizhou in Zhejiang Province were initiated. As pointed out by Connor M. Kennedy of the U.S. Naval War College, maritime militia personnel occupy a deliberately ambiguous position as both civilians and quasi-military actors, and this dual identity allows China to operate effectively in the gray zone between peace and conflict.

The Xi Jinping administration's efforts to organize maritime militia across the coastal areas should be understood as part of a broader strategy supporting China's military expansion into the Pacific. In June 2025, China simultaneously deployed two aircraft carriers to the Pacific for the first time in history. According to Japan's Joint Staff Office, one of these carriers, the Liaoning, operated in waters near Palau, approximately 990 kilometers south of Okinotorishima, within the exclusive economic zone of Yap in the Federated States of Micronesia.

China is currently preparing to exert pressure on Taiwan not only from the mainland but also from the Pacific, while simultaneously attempting to deny U.S. access to the waters between the First and Second Island Chains. To maintain such a strategy, China must secure its rear, meaning it needs to constrain the activities of the JMSDF and the Japan Coast Guard in the East China Sea. If it can use the maritime militia to disrupt or delay the movements of the Coast Guard and the JMSDF, Beijing can more effectively assert control over these waters.

In this context, the maritime militia is not merely a coastal defense force but an element supporting China's broader efforts to blockade key straits and maritime areas. It has the potential to weaken deterrence along the First Island Chain and to reshape the regional balance of power in favor of China.

Specific threats that Japan should be wary of include, first, the possibility that large-scale fishing fleets could complicate the Japan Coast Guard's patrol capabilities in the territorial waters around the Senkaku Islands. In 2016, 200 to 300 Chinese fishing vessels gathered near the islands, after which vessels from the China Coast Guard repeatedly intruded into Japanese territorial waters. A decade later, the scale of such activities could be much larger. The Japan Coast Guard maintains a constant presence with patrol vessels of around 1,000 tons, but future incidents could see thousands of vessels operating in coordination with the China Coast Guard.

Second, China is gaining an advantage in both the physical and information domains by creating an asymmetric narrative of fishermen versus naval vessels or fishermen versus government ships. In 2009, vessels from China's maritime militia attempted to disrupt the operations of the U.S. Navy survey ship Impeccable in the South China Sea. The same logic applies to cognitive warfare. Beijing can portray Japan's patrol vessels as "harassing civilian fishing boats," framing law enforcement actions as acts of national aggression. Such narratives have been repeatedly deployed in the South China Sea and could be replicated around the Senkaku Islands or during a Taiwan contingency.

Third, there is the potential for a "high-tech people's war." Xi Jinping is currently adapting Mao Zedong's concept of mass mobilization through the integration of maritime militia and new technologies. Reports indicate that these units are receiving training in the operation of unmanned systems. In times of crisis, there is a possibility of deploying large numbers of autonomous underwater vehicles (AUVs) for reconnaissance and sabotage, including attacks on undersea cables. Chinese documents also suggest that these highly mobile units may be tasked with electronic warfare operations such as disruption.

The organizational restructuring of the JMSDF, carried out under such circumstances, signifies not just internal efficiency but an adaptation to the changing strategic environment. The integration into three surface combat groups allows for a simplification of the command structure and an improvement in responsiveness, enhancing the ability to address potential crises around the Senkaku Islands and the Taiwan Strait. At the same time, this restructuring reflects the evolution of the JMSDF's role within the framework of the Japan-U.S. alliance.

Furthermore, it is noteworthy that the Japanese government is considering the dispatch of JMSDF minesweeping units to the Strait of Hormuz. Prime Minister Sanae Takaichi stated in the House of Councillors Budget Committee on March 25 that decisions regarding future deployments would be made "in accordance with the law while monitoring the situation." The JMSDF possesses advanced mine-clearing capabilities and has a track record of dispatching minesweeping units to the Persian Gulf after the Gulf War in 1991. Currently, this deployment is being considered as an option following the establishment of a ceasefire between the U.S., Israel, and Iran.

The consideration of dispatching units to the Strait of Hormuz indicates that Japan's security policy is expanding its geographical scope. At the same time, it is clear that Japan is facing two distinct maritime security demands: the immediate threat posed by the activities of China's maritime militia in the East China Sea and the distant challenge of ensuring the safety of maritime traffic routes in the Middle East. This dual challenge necessitates new strategic judgments regarding the JMSDF's capabilities and resource allocation.

As China is likely to deepen the coordination between its maritime militia and the China Coast Guard in the East China Sea, Japan must reaffirm its strategy to address the gray zone challenges posed by this coordination without overly focusing on military tensions surrounding Taiwan. The organizational restructuring of the JMSDF is an important step in this direction, but a comprehensive approach is required, including strengthening collaboration with the Japan Coast Guard, enhancing intelligence, surveillance, and reconnaissance (ISR) capabilities, and deepening information sharing with allies.

The current situation in the East China Sea demonstrates a new form of strategic competition that differs from traditional military confrontations. The sight of thousands of fishing vessels forming orderly formations symbolizes an era where the boundaries between peacetime and wartime are blurred, and the distinction between civilian and military is deliberately obscured. Japan's response must be multilayered, involving the establishment of legal frameworks, enhancement of operational capabilities, and deepening of international cooperation. The organizational restructuring of the JMSDF is merely the beginning of this long-term endeavor.