What Did The Navy Do In the South China Sea?

After the U.S.S. Lassen’s freedom of navigation operation (FONOP) in the Spratly Islands last week, we wrote that the Lassen and the accompanying P-8 Poseidon aircraft appeared to have conducted normal military operations inside 12 nm around Subi Reef. That was important because normal military operations are not “innocent passage,” a demonstrably nonthreatening mode of transiting another nation’s territorial seas. By conducting normal operations inconsistent with innocent passage, the United States appeared to have demonstrated that it does not recognize a territorial sea around Subi—and, by extension, China’s other artificial islands built on “low-tide elevations.” DOD, however, did not specifically confirm that the Lassen had conducted normal operations, and kept mum on the precise legal rationale for the operation.

New reporting on the Lassen operation suggests that the FONOP might have been consistent with innocent passage after all. It appears that the Lassen may have transited within 12 nautical miles in accordance with innocent passage, while the accompanying surveillance aircraft (which cannot operate consistent with innocent passage) remained outside of the 12 nm zone. Additional reporting suggests that the Lassen’s fire control radar was turned off and that it did not launch or recover helicopters inside of 12nm—both activities that would have been obviously inconsistent with innocent passage.

These new details don’t conclusively establish that the Lassen’s transit was innocent passage, as some authors now suggest. As this helpful Asia Maritime Transparency Initiative graphic shows, there are several ways a vessel can transit within 12 nm to challenge the assertion of a territorial sea. Surveillance is one such demonstrative activity, as is the use of fire control radars or helicopters. If the Lassen loitered within 12 nautical miles, however, or failed to move in a direct and expeditious manner through the zone, this would have been inconsistent with innocent passage too. Some authors, including Julian Ku writing for Lawfare, have suggested that the U.S. Navy has confirmed an innocent passage transit. We are not sure that these presumably-unauthorized disclosures amount to an official confirmation.

This lack of clarity is nonetheless a problem for U.S. foreign policy and for international law. We agree with Ku that, if allowed to harden, the widespread belief that the Lassen conducted innocent passage would be extremely damaging; indeed, it could make the operation worse than having done nothing at all.

Let’s assume that the Lassen did conduct unannounced innocent passage. On the modestly positive side, such an operation would have repudiated China’s view that innocent passage through the territorial sea requires advance notice and permission from the coastal state. But that modest benefit would be greatly outweighed by what the operation would have implicitly conceded: If the Lassen did indeed conduct innocent passage, China could assert that the operation demonstrated the United States’ acquiescence in China’s claim to a territorial sea around its artificial islands, as Ku observes. (Under UNCLOS, “low-tide elevations” like Subi Reef are not entitled to a territorial sea, even if an artificial island is built on top of them.) We pointed this potential concession out as a downside of what we termed “Option 1” in our first poston this issue.

This is a problem both for U.S. maritime policy and for international law. The policy concerns are not hard to imagine: As James Kraska of the Naval War College has explained, there are “hundreds of rocks, reefs, skerries and cays in the South China Sea.” “[I]f the international community recognizes the maximum theoretical rights generated by each of them, the oceans and airspace will come to look like Swiss cheese and be practically closed off to free navigation and overflight.” Recognizing territorial seas around artificial islands would undermine freedom of navigation and enhance China’s control over the region’s vital airspace and sea lanes.

The widespread perception that the Lassen conducted an innocent-passage transit would also be damaging for the future development of international maritime law. Customary international law is formed by the accretion of state practice motivated by a sense of legal obligation. (This sense of legal obligation is known in the trade as opinio juris.) Each instance of state practice accompanied by opinio juris is a brick in the wall of customary international law. And an instance involving the lone global superpower is an especially big brick: If the all-powerful United States is bound to obey a legal rule, isn’t everybody?

In our first post on this issue, we wrote that “the Pentagon should, and … presumably intends to, clearly explain the legal view underpinning whatever action it takes.” DOD hasn’t done so yet, and the result has been widespread confusion. The Pentagon needs to clarify what happened at Subi Reef—and, more importantly, what message it intended to send.