South China Sea: What 12 Nautical Miles Does and Doesn’t Mean


The U.S. Navy is reportedly preparing to conduct “freedom of navigation” (FON) operations, sending one or more surface ships within 12 nautical miles (nm) of Chinese-claimed features in the South China Sea. The administration has been pressured to go ahead with this demonstration of U.S. views on conduct at sea, but the terms of the public debate have failed to match the legal and political implications.

Though details are scarce, unnamed U.S. and Asian officials told The New York Times U.S. allies were being briefed on the plans, which reportedly involve traveling near one or more of China’s recently constructed or expanded outposts. Daniel Kritenbrink, the new senior director for Asian affairs at the U.S. National Security Council, reportedly told a closed-door meeting the decision to go ahead was already made.

Over the past several months, a media narrative had emerged that pitted the Department of Defense against the White House and the State Department, with the military pushing for FON operations within 12 nm and the civilians more cautious.

Senator John McCain summarized the increasingly heated rhetoric in favor of the demonstration neatly: “We continue to restrict our Navy from operating within a 12 nautical mile zone of China’s reclaimed islands, a dangerous mistake that grants de facto recognition of China’s man-made sovereignty claims.” Colin Clark of Breaking Defense echoed McCain in what became something of a mantra among those favoring a stronger stance against Chinese construction in the Spratly Islands: “I understand that we have granted China de facto recognition of the temporary structures so far by ordering our maritime and air forces to observe a 12 nautical mile limit.”

These statements and many others implied that, by not sailing military vessels within 12 nm of Chinese outposts, the United States recognizes either Chinese sovereignty over the maritime features or recognizes a Chinese territorial sea surrounding them. Both of those implications are arguable at best, and more likely false.

Recognizing Nonexistent Claims Through Inaction

Chinese Ministry of Foreign Affairs (MFA) statements in response to questions about potential intra-12 nm FON operations illustrate why the debate did not correspond with reality. MFA spokesperson Hua Chunying said last week, “There is no way for us to condone infringement of China’s territorial sea and airspace by any country under the pretext of ‘maintaining the freedom of navigation and overflight.’” In May, Hua said: “The Chinese side advocates the freedom of navigation in the South China Sea, yet the freedom definitely does not mean that foreign military vessels and aircrafts can enter one country’s territorial waters and airspace at will.”

The Chinese government has not, however, made statements asserting claims specifically to territorial seas surrounding the outposts in question. Hua’s statements, therefore, are part of a carefully cultivated ambiguity cultivated by Chinese officials — an ambiguity inherent in the still-ambiguous nature of Chinese claims within the so-called nine-dash line.

In essence, McCain and others have argued the United States, through inaction, is recognizing claims China has been careful never to make. To understand why requires a brief discussion of maritime law. The significance of 12 nm derives from the fact that the UN Convention on the Law of the Sea (UNCLOS) generally grants coastal states jurisdiction over a 12 nm territorial sea emanating from the coast. Since China has not declared the lines from which a territorial sea would be drawn in the South China Sea, operating within 12 nm is not dealt with concretely by the UNCLOS rules governing activity in territorial seas.

Nonetheless, the message sent by FON operations within 12 nm of Chinese-occupied outposts differs depending on the nature of the underlying maritime feature.

While avoiding the highly technical and sometimes confusing language of UNCLOS, it is useful to differentiate between two types of features currently occupied by China in the Spratly Islands. We can call one type “constructed islands.” Constructed islands were built on top of natural features that did not originally rise above the water at high tide. Entering within 12 nm of a constructed island sends the message that the United States believes, in accordance with UNCLOS, that construction on top of features that were fully submerged at high tide does not produce a right to a territorial sea — and so even if sovereignty were settled, there would be no 12 nm limit.

The other type of feature we can call “enlarged islands.” As the name suggests, enlarged islands are produced by adding to natural features, at least part of which originally reached above water at high tide. Should sovereignty over such enlarged islands be settled, a territorial sea could be declared. Entering within 12 nm of enlarged islands, therefore, could be construed to be transiting a yet undeclared territorial sea. Should China wish to object in the language of UNCLOS, it would have to claim that the U.S. ships did not satisfy the rules of “innocent passage,” which allows ships to transit territorial seas under certain conditions. China has pushed for a norm that for military vessels should notify or seek permission from the coastal state before innocent passage, something not provided for in UNCLOS.

Objectives and Risks

As you can see, the legal significance of FON operations is highly contingent on settlement of sovereignty, the natural history of the feature, and claims made by the states. The legal significance of such moves is further muddied by the fact that the United States is not a party to UNCLOS, since it has not been ratified by the Senate.

Clearly something beyond the law is going on here, and if the proposed operations go forward, the question will be which type or types of outpost are involved and how China’s government responds. What the U.S. Navy eventually does should depend on the overall objectives.

One U.S. objective might be to force China’s government to make explicit claims in the language of UNCLOS, claims that could later be challenged through mandatory dispute resolution under the convention by a state that has actually ratified it. U.S. requests in official and unofficial forums for China to clarify its claims have not produced results, so FON operations could be intended to further that goal. Disrupting China’s ambiguity carries risk, however, since Chinese officials might find themselves forced into maximalist claims that public opinion would make it hard to walk back.

Another U.S. objective could be to continue the longstanding U.S. practice of FON operations while being seen to be “doing something” about China’s South China Sea activities that are objectionable to other claimants and regional states. This desire to have U.S. efforts be seen publicly fuels suggestions from non-authoritative Chinese sources, such as retired military officers and media analysts, who have said China could respond to FON operations with potentially dangerous tactics like ramming ships. If the goal were merely continuing the U.S. FON program, a quiet mission, also sailing past outposts constructed by Vietnam or other states, would have sufficed.

U.S. officials may believe the Chinese strategy has been to change the “facts on the water” while avoiding specific claims that might not find support under international law. If so, the risk of locking Chinese officials into a maximalist claim, or provoking a potentially dangerous response, might be deemed acceptable. If this is the case, the United States might do better to engage in a joint patrol with an ally who is a member of UNCLOS, since that state could potentially avail itself of dispute resolution under the convention. The advance publicity given to U.S. deliberations could also allow Chinese authorities to prepare to challenge the United States peacefully and avoid catching local security forces off-guard.

In any event, if the U.S. government goes forward with these plans, it clearly intends to send a public message. Observers should heed the details of that message, but the U.S. government should be prepared for media, foreign governments, and public opinion to misread or distort its intentions.

Graham Webster (@gwbstr) is a researcher, lecturer, and senior fellow of The China Center at Yale Law School. Sign up for his free e-mail brief, U.S.–China Week.

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