The Challenge of Maritime Hybrid Threats in the East China Sea
On 8 December 2008, two Chinese MLE vessels entered waters around the Senkaku Islands, the front line of territorial disputes between Japan and China, for the first time. Since then, China has regularly dispatched MLE vessels to challenge Japan’s effective control over the islands, claiming sovereignty over them as part of the so-called “salami-slice strategy,” a steady progression of small actions with hidden long-term motives.

1. Definition of maritime hybrid warfare and its means and implementation
The concept of “hybrid warfare/threats” originated with operations against Israel by Hezbollah in the 2006 Lebanon War that was achieved using hybrid methods. Russia’s annexation of Crimea in 2014 also offers a good example of gray zone methods that fall just short of open conflict, blurring military and nonmilitary domains with techniques such as deploying “Little Green Men” of ambiguous affiliation, extensive use of disinformation, false flag operations, cyber warfare, electronic warfare, and infrastructure sabotage. The term “hybrid warfare” was first used by Frank Hoffman in 2007, and it is considered a serious threat by NATO.
The use of ambiguous means that blend military and nonmilitary domains is not limited to land-based operations. In the Indo-Pacific region, which has a large maritime area, hybrid warfare extends to the seas. Kotman identifies the following characteristics of marine hybrid threats: First, they emerge mainly in coastal and offshore waters rather than in the distant seas. Second, rather than “gray hulls” (naval vessels), they are likely to utilize “white hulls” (Coast Guard vessels) and government ocean survey ships, both of which are fully exempt from the jurisdiction of any state other than the flag state on the high seas (and in territorial waters of coastal countries under certain conditions defined by UNCLOS, the 1982 United Nations Convention on the Law of the Sea). Third, the focus of this type of warfare would be to sabotage infrastructure such as submarine cables, oil wells and gas facilities, obstruct maritime trade routes and challenge national sovereignty. Fourth, the diversity of means makes these acts difficult to detect and may delay a response (Kotman, 2021). It is also important to note that maritime hybrid warfare includes aspects of information warfare and “cognitive warfare,” which attempt to change people’s ways of thinking and even behavior patterns.
A hybrid threat is not a situation in which a wide variety of threats exist separately, but rather a situation in which each threat works in synergy with others that share common strategic goals. Here, I define maritime hybrid threats as “threats posed by attempts to change the status quo in the maritime domain through the extensive use of ambiguous means in both military and nonmilitary domains while remaining below the threshold of the opponent’s red line.”
2. Increasing challenges by CCG vessels and Chinese research ships
The Maritime Law Enforcement (MLE) agency, also called the Coast Guard or Marine Police, is generally used for domestic law enforcement to control illegal, unreported, and unregulated (IUU) fishing; to detect smuggling and trafficking; to counter piracy; to conduct search-and-rescue operations; and to protect the environment and marine resources in territorial waters and the Exclusive Economic Zone (EEZ). Recently, however, MLE vessels have been actively utilized by coastal states for hybrid warfare. Generally, “white hulls” (a reference to the color of Coast Guard vessels) are recognized as less aggressive than naval “gray hulls,” and therefore suitable for implementing sensitive operations by coastal states. In that capacity, MLE vessels function as a buffer to prevent collisions and the unintended escalation of collisions into armed conflicts (Bateman, 2003). In addition, Article 96 of UNCLOS classifies government ships used for noncommercial purposes on the high seas as “fully exempt from the jurisdiction of any state other than the flag state.” This immunity makes these vessels ideal for a flag state that wants to impose its maritime rights beyond its territory without risking clashes.
A milestone of CCG activities in the East China Sea
On 8 December 2008, two Chinese MLE vessels entered waters around the Senkaku Islands, the front line of territorial disputes between Japan and China, for the first time. Since then, China has regularly dispatched MLE vessels to challenge Japan’s effective control over the islands, claiming sovereignty over them as part of the so-called “salami-slice strategy,” a steady progression of small actions with hidden long-term motives.
An analysis of recent activity by China Coast Guard (CCG) vessels reveals a continuous Chinese presence around the islands. In addition, the qualitative and quantitative strengthening of China’s MLE capabilities make this behavior more durable. This can be seen in four areas:
First, CCG vessels regularly intrude into the territorial waters of the Senkaku Islands following a “4-1-2” formula: four vessels enter the Japanese territorial waters of the islands once a month for up to two hours (the formula evolved from “3-3-2” in 2013 to “4-3-2” in 2016 to “4-2-2” in 2018), while increasing number of irregular intrusion and chasing Japanese fishing boats in territorial waters around the islands has increased for asserting China’s “sovereign right” to control over the islands and harassing Japanese fishing boats. This trend is particularly noticeable during the “fishing ban period” unilaterally declared by China (in waters between 12 and 26 degrees, 30 minutes north latitude from 1 May to 16 August). Chinese authorities are able to detect when Japanese fishing boats leave from Ishigaki-Jima or Miyako-Jima islands – it is unclear how – so that CCG vessels can monitor and chase these boats, observing fishing activities in Japanese territorial waters. The CCG vessels do not attempt to seize boats, conduct onboard inspections, confiscate equipment, or force signatures on documents, as they do to Vietnamese fishing boats in the South China Sea.
Second, CCG vessels are staying longer in the contiguous waters, which are not territorial waters but nonetheless areas where coastal states are allowed to utilize the waters for customs, sanitary, fiscal and immigration regulations. Prior to 2019, CCG vessels sailed in contiguous waters for several days before intruding into Japanese territorial waters. Their average stay in the contiguous waters in 2015 was 20 days a month, which by 2018 had dropped to 13 days a month. Since 2019, however, the continuous presence of CCG vessels in contiguous waters has increased, reaching a record high of 157 continuous days in 2021. That year, CCG vessels spent a total of 332 days in contiguous waters around the Senkaku Islands.
Third, the amount of time that CCG vessels spend in Japan’s territorial waters has also increased, to a record high of 65 hours, 15 minutes on 5 July 2022. This extended tracking and observation of Japanese fishing activities during the “fishing ban period” is apparently an attempt to restrict Japanese fishing activities. It may also be a reaction to indicate to Chinese fishing vessels during that period on the high seas around the islands where EEZ of China and Japan are overlapping.
Fourth, the CCG-dispatched fleet has been modernized and improve their capabilities. After China consolidated five maritime law enforcement agencies in 2013, it usually consisted of four vessels, a mix of various types of patrol and law enforcement vessels. In recent years, however, there have been new types of patrol vessels, and the composition of the fleet has been streamlined. The duration of deployment is also increasing, from 1-2 weeks to 30 days, with the ships staying in contiguous waters even during bad weather, such as typhoons. These trends reflect an improvement in the skills of the crews and the level of sophistication in operations. They show that the development of maritime law enforcement capabilities in accordance with the long-term goals of the Chinese authorities is paying off.
3. Increasing use of drones
The operational effectiveness of drones and their limitations were demonstrated by their active use for reconnaissance and attack by the Azerbaijani in the Nagorno-Karabakh conflict in September 2020. Furthermore, in Russia’s full-scale invasion of Ukraine, both sides have operated a variety of drones for information-gathering, reconnaissance, target guidance, and attack purposes, suggesting that we are truly entering a new era of drone operations. Drones are well-suited to hybrid warfare, so it is natural that their scope, applications, and frequency of use has grown in the Indo-Pacific.
Characteristics of drones
Drones offer several advantages, but also come with limitations. For example, unlike manned aircraft, drone operations pose no risk of losing human lives. In addition, although operators need to be changed, drones themselves can operate continuously for up to 48 hours (or more when they are combined with AI and other autonomous systems). This makes it possible to conduct patrol and observation missions over a wide area of ocean that cannot be covered by manned aircraft. Furthermore, they can be developed and produced at a relatively low cost compared to manned aircraft, and the costs over their operational life cycle are also low. They also offer a high degree of operational flexibility. On the other hand, they are slower than manned military aircraft and can be easily shot down by air defense.
In addition to unmanned aerial vehicles (UAV), unmanned surface vehicles (USV) and unmanned underwater vehicles (UUV) are also expected to be employed in the future. So, it will be important to identify drone operators, develop anti-drone warfare capabilities and tactics, and establish laws and regulations that will provide rules and grounds for operating and countering drones.
Milestones and trends in using drones in the East China Sea
The first recorded Chinese drone operation in the East China Sea occurred on 9 September 2013, when a Chinese UAV flew into the airspace near the Senkaku Islands, causing the Japan Air Self-Defense Force (JASDF) to scramble F-15 jet fighters in response. JASDF subsequently identified the UAV as Wing Loong I, later identified as a BZK-005 by Jane’s Defense Weekly. After that, no Chinese drone operations were seen until May 2017, when a small commercial drone took off from a CCG vessel and flew over the Senkaku Islands. The Chinese Ministry of Foreign Affairs claimed that the drone was flown by Chinese media for filming.
But starting last year, Chinese drone operations became much more active. On 25 August 2021, a BZK-005 reconnaissance UAV accompanied by a Y-9Q patrol aircraft and a Y-9JB electronic intelligence aircraft flew from the East China Sea over the Miyako Channel and into the Pacific Ocean before returning to mainland China. Furthermore, on the following day, a TB-001 reconnaissance/attack UAV flew a similar route over the Miyako Channel and into the Pacific Ocean, accompanied by a Y-9Q and a Y-9JB. This was the first time JASDF had confirmed an actual TB-001. At the time, joint exercises between the Royal Navy’s aircraft carrier Queen Elizabeth and Japan Maritime Self Defense Force (JMSDF) vessels were being conducted in the East China Sea and Pacific Ocean. In May 2022, a BZK-007 multipurpose UAV, similar to a small civilian single-engine aircraft, was first observed in the overlapping Japanese and Chinese air defense identification zones (ADIZ) in the East China Sea.
It is interesting to note that when a TB-001 flew in August 2021, a Y-9s accompanied and observed the flight, but when a TB-001 flew the same route through the Miyako Channel to the Pacific Ocean in July 2022, it was alone. Similarly, in an incursion on 4 August this year, a TB-001 and a BZK-005 flew independently from mainland China, conducted observation missions in the exercise area and airspace declared around Taiwan after Nancy Pelosi’s visit, then returned to mainland China, flying a total distance of 3,200 km. During this time, it is likely that information was exchanged with an operations center in China via satellite. Which would mean that China has established a long-range reconnaissance operation system using medium-altitude, long-endurance (MALE) reconnaissance UAVs.
China also conducted navigational tests of a 200-ton tumble-form USV in June 2022, and had already unveiled two HSU-001 UUVs during a military parade in October 2019. It is expected that China will establish an operational system for them soon. To counter these drones, there is a need for either a “drone-by-drone” response mechanism or vigilant monitoring systems using space-based sensors and other advanced equipment.
4. Means and capabilities required to deal with maritime hybrid warfare
In dealing with maritime hybrid warfare, it will be important to (1) clarify red lines; (2) deter challenges by taking resolute measures; and (3) detect hybrid threats at an early stage. To this end, information sharing and capacity-building by regional countries for Maritime Domain Awareness (MDA) is crucial.
Government vessels
The CCG will likely continue to deploy modern and numerically superior fleet in disputed waters and establish a sophisticated operations system for these vessels. More vessels, crews with improved skills and flexible and established operations are intended to exhaust responders, including the Japan Coast Guard (JCG). An expected increase in the duration of Chinese vessels spend in contiguous and territorial waters will also exhaust the response capabilities of Japan, which has a limited budget, human resource, and number of Coast Guard vessels.
To strengthen JCG functions, the Japanese government is in the process of substantially increasing JCG’s budget as part of a drastic reinforcement of defense capabilities starting in FY2023. The total budget for JCG was approximately 261.8 billion yen (17.73 billion USD) in the FY2022 budget, but the Kishida administration is reportedly considering more than doubling the 150 billion yen earmarked for operations and equipment, excluding personnel expenses (as reported by Japanese media on 20 October).
As political tensions between China and Japan increase, it is conceivable that the situation could escalate to a complete shutdown of Japanese fishing activities if CCG vessels stop fishing boats to conduct onboard inspections in Japanese contiguous waters, or use coercive force involving firepower. For this reason, it is necessary to improve the bulletproof capability of JCG vessels. The number of Japanese fishing boats operating in the waters around the Senkakus is already shrinking, due to the extended duration of CCG vessels and the threat of being pursued by them. Therefore, efforts to support Japanese fishing in the Senkaku area are also needed.
Drones
China, already a global drone power, is expected to increase its long-range operations in information- gathering, reconnaissance and targeting with various high-altitude, long-endurance (HALE) drones of ambiguous affiliation. This is aimed at exhausting Japanese response capabilities. Currently, Japan’s Air Self-Defense Force responds to Chinese drones with F-15 fighters, E2C Early Warning Aircraft and E-767 AWACS. However, manned aircraft have high operational costs and limited service life. Drone tracking and observation are more efficiently handled by ground, maritime and space sensors.
China is also expected to increase the operation of MALEs and small drones (including civilian drones), which can be used not only for information-gathering and reconnaissance, but also for suicide attacks as Russia conducts in Ukraine with Iranian drones. Already, the increase in unidentified drones flying over Kinmen Island, Taiwan is indicative of this trend. Furthermore, it will be necessary to prepare for an increase in quadcopters and other small civilian drones deployed from Chinese government vessels. Securing anti-drone capabilities (with electronic jamming devices, small-bore kinetic arms and MANPAD defense systems) will be important to counter these challenges from MLE vessels.
However, the most important strategy for Japan is to articulate clear “red lines” or principles. In May 2017, the Abe administration stated that it considered the use of weapons against airspace incursions, including drones, to be permissible only when they fall under the requirements of self-defense or emergency evacuation as “necessary measures” under the Self-Defense Forces Law. The government said it was developing guidelines and rules for dealing with airspace violation by drones, but to date none have been announced. Therefore, Tokyo needs to follow the example of Taiwanese President Tsai Ing-wen, who ordered the Ministry of National Defense to take necessary and strong countermeasures, although she emphasized that Taiwan will not give China an excuse to start a war. She drew this red line on 30 August 2022. Two days later, on 1 September, the Taiwanese military struck down a drone of unknown affiliation.
This raises another important point: the UAVs operated by China typically do not have any markings on them that indicate their nationality or affiliation. This makes them ideal tools for hybrid warfare, creating confusion and making it difficult for opponents to respond. This could significantly change the situation in the East China Sea, where so far both sides have used “white hulls” instead of “gray hulls” to avoid escalation to a military conflict. While UAVs are currently being introduced by various countries and small civilian drones are also flying freely, it is necessary to establish regional rules that require the nationality and affiliation of drones to be clearly shown on the equipment, thereby creating a mechanism to avoid unexpected accidents and escalation.
Meanwhile, the gap between China, currently the world’s leading drone production and operation powerhouse, and Asian countries lagging in drone development, including Japan, continues to widen every day. This reinforces the need for regional rules and agreements governing the use of autonomous weapons such as AI-controlled drones.
Conclusion
There is no sign that the rising tensions in the U.S.-China persistent power competition in all domains will heal in the years ahead and hybrid warfare will become a crucial tool for China, which wants to expand its influence in a gray zone salami-slicing manner that will avoid a direct military clash with the US. Therefore, maritime hybrid warfare will pose a growing threat in the Indo-Pacific region.
This means the current “strategic ambiguity” approach to maintaining regional stability in Asia will no longer work. An effective strategy needs to be more explicit and include setting clear “red line” that anticipates and deters hybrid threats. However, in making the red line unambiguous, we have to prepare for and be willing to use coercive force if it is required. We are faced with a choice about whether we should maintain the strategic ambiguity that allows hybrid warfare, or whether we should reduce ambiguity and rely on coercive deterrence.
References
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- Brands, Hal. Paradoxes of the Gray Zone, Foreign Policy Research Institute, 5 February 2016, https://www.fpri.org/article/2016/02/paradoxes-gray-zone/
- Erikson, Andrew D. and Ryan D. Martinson. China’s maritime Gray Zone Operations, Naval Institute Press, 2019.
- Kotman, Turkay. Maritime Hybrid Threats, Maritime Security Centre of Excellence, August 2021. https://www.marseccoe.org/wp-content/uploads/2021/08/Maritime-Hybrid-Threat.pdf
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