Coast Guard Lawfare: How Beijing Is Rewriting the Rules of the Taiwan Strait With White Hulls

On February 1, 2021, China's Coast Guard Law formally took effect. It is a legal document of fewer than 6,000 characters, yet it put neighboring countries and international observers on high alert.

The two most critical provisions:

Article 22: Where foreign military vessels or foreign government vessels operate within waters China claims as its "jurisdictional waters," coast guard agencies may take "necessary measures."

Article 20: Where foreign nationals conduct illegal operations or foreign entities carry out illegal construction on islands and reefs China claims sovereignty over, coast guard agencies may "order a halt and forcibly demolish" them.

Article 21: Within waters China claims jurisdiction over, if a foreign vessel violates Chinese laws and regulations, measures such as boarding, inspection, and seizure may be taken.

More central still is Article 46's authorization framework for the "use of weapons," which gives coast guard ships a legal basis for using weapons under specific circumstances. ^[5]

The problem is that the definition of "waters China claims jurisdiction over" overlaps extensively with the claims of other countries — Taiwan, Japan, the Philippines, Vietnam — and the Coast Guard Law itself offers no explanation whatsoever for this contradiction. This legislative strategy is deliberate: it wraps "what I say goes" in the form of law, then uses action to fill in the blanks the wording leaves behind.

The Philippine foreign secretary explicitly called it a "piracy law" once the Coast Guard Law took effect; the foreign ministries of the United States, Japan, and Australia also voiced concern in turn. But criticism has stayed just criticism, while China's coast guard ships have already begun acting on this law. ^[6]

From the South China Sea to the Taiwan Strait, the actions of China's coast guard ships follow an observable pattern that military analysts usually call "gray zone tactics": the intensity of each action is systematically kept below the threshold that would trigger a military response from the other side, yet is still enough to accumulate real effects on the ground.

Around Taiwan, this tactic takes several concrete forms:

Approaching and shadowing fishing boats. Coast guard ships close in on Taiwanese fishing boats, record their positions, and sometimes demand to inspect their catch and permits, declaring that the boats are "operating illegally in waters under Chinese jurisdiction." The process does not necessarily involve force, but it already establishes a de facto claim to law-enforcement jurisdiction.

Driving fishing boats off their grounds. Using radio broadcasts or by closing distance, they force Taiwanese fishing boats to leave the waters where they are working. Boats that are driven off often dare not report the incident, for fear of causing bigger trouble — this creates a "silence bias" that makes official statistics undercount the real number of incidents.

Carrying out "routinized patrols" around Taiwan's outlying islands. Chinese coast guard ships have appeared with increasing frequency near Kinmen, Matsu, Dongyin, and other outlying islands. After 2023, language describing "routine coast guard patrols" even began appearing around Kinmen, pushing the jurisdictional claim from an operational tactic toward an administrative definition. ^[1]

Shifting into a blockade posture during joint military exercises. When the PLA conducts military exercises, coast guard ships appear around Taiwan at the same time, forming a "military-police coordination" blockade posture. This kind of coordinated deployment was observed both in the 2022 military exercises and in the 2023 "Joint Sword" exercise. ^[4]

The subtlety in this strategy's design is this: each individual incident is "not big enough" on its own, making it hard for Taiwan to find an appropriate response — report it to the media? Escalate? Or handle it quietly? This "awkward middle ground" is exactly what Beijing wants to create.

Taiwan has its own Coast Guard Administration, equipped with coast guard vessels rather than warships. This arrangement itself reflects Taiwan's dilemma: responding to a coast guard ship with a warship would raise the level of military confrontation; responding with a coast guard vessel usually leaves Taiwan at a disadvantage in tonnage and equipment, and its legal authorization is also not clear enough.

The largest vessels of Taiwan's Coast Guard Administration displace roughly 1,000 to 3,000 tons, while China's newest coast guard cutters — such as the Haijing 2901 — exceed 10,000 tons, a tonnage class approaching that of an aircraft carrier, though flying a coast guard flag. ^[8] This "tonnage asymmetry" leaves Taiwan's coast guard at a structural disadvantage in actual standoffs at sea.

More critical still is legal authorization. Taiwan's Coast Guard Act and its Coast Guard Administration organization act are relatively vague on "what can be done in the gray zone" — boarding an illegal foreign fishing boat is one thing, but what can be done about "a coast guard ship claiming to enforce Chinese law"? There is no clear provision for that.

The key legal gap: Taiwan currently lacks a complete "legal framework for maintaining maritime claims" that clearly defines the extent of the waters it claims jurisdiction over, what legal measures it can take against intruding foreign law-enforcement vessels, and the procedures for coordinating with military force. Filling this gap is, in itself, a defensive measure in this legal war.

The Philippines faces almost the exact same challenge in the South China Sea, and its response strategy over the past few years offers lessons Taiwan can draw on.

Move one: film it, and put it out. Since 2023, the Philippine Coast Guard has systematically video-recorded every instance of interference by Chinese coast guard ships and proactively released the footage. This practice has brought gray zone incidents that once existed only in diplomatic cables into the view of global media, generating international public pressure that Beijing has found hard to digest. ^[9]

Move two: find a legal ally. The Philippines already won a favorable ruling from an arbitral tribunal back in 2016 (the "South China Sea Arbitration"). Although China refuses to recognize it, the ruling gives the Philippines' maritime claims a foundation in international law, letting the Philippines take the position, in every incident, that "I am in waters international law recognizes as mine."

Move three: bring in allied witnesses. The Philippines has begun inviting coast guard ships or warships from the United States, Japan, and Australia to take part in joint patrols, so that every act of interference by a Chinese coast guard ship has allied witnesses present. This has substantially raised the cost of China's actions. ^[10]

Taiwan has room to improve on all three fronts, but "bringing in allied witnesses" is the hardest — Taiwan's particular diplomatic position makes it difficult to conduct this kind of joint patrol in an open, formal manner.

Beyond the analytical framework, it is Taiwan's fishermen who directly bear the impact of this coast guard lawfare.

Fishermen in southwestern Taiwan have long fished in traditional grounds — the South China Sea, and waters west of the median line of the Taiwan Strait — where an informal but understood practice of use developed over the past four decades. The appearance of Chinese coast guard ships has broken this practice, forcing fishermen to choose: keep operating in the traditional grounds at their own risk, or retreat to safer waters closer to Taiwan's coast that yield a smaller catch. ^[3]

This "shrinking fishing grounds" effect is hard to quantify in official data, but it is a widely recognized reality within Taiwan's fishing communities. Its significance is not just a matter of fishermen's livelihoods — it is also a lived, popular sense of eroding sovereignty: Taiwanese people directly feeling that "a stretch of sea I used to be able to go to, I can't go to anymore."

Accumulated over time, this popular sense of loss is itself one of the effects of cognitive warfare.

Facing this coast guard lawfare, Taiwan has several feasible layers of strategy:

Legal: strengthen documentation of Taiwan's own maritime legal claims, clearly defining the waters Taiwan claims jurisdiction over and their legal basis; amend the Coast Guard Act to fill the authorization gap in the gray zone; and build a systematic mechanism for recording and publicizing incidents, following the Philippines' "transparency offensive."

Capability: increase the tonnage and technical equipment of the Coast Guard Administration's vessels to narrow the tonnage gap with Chinese coast guard ships; build coordinated response procedures among the coast guard, navy, and air force; and strengthen intelligence-sharing mechanisms with the United States and Japan, so that Taiwan is no longer the only one tracking the movements of Chinese coast guard ships around it.

Diplomatic: wherever diplomatic contact allows, put the coast guard ship issue on the agenda of Taiwan-U.S. and Taiwan-Japan dialogues; and support the Philippines' and Vietnam's countermeasures against China's lawfare in the South China Sea, forming a joint front.

At its core, lawfare is a war over definitions — whoever's definition comes to dominate in reality wins in a legal sense. Taiwan cannot let this war be waged in silence.