The Latest US Freedom of Navigation Operation Opens the Legal Door to More Aggressive US Challenges to China’s Artificial Islands

[This piece has been updated where noted.]

Last week, the US Navy conducted another freedom of navigation operation (FONOP) in the South China Sea. Although this FONOP may seem just like the others, I believe it is legally different because it is the first recent FONOP to openly and decisively reject a Chinese claim of maritime sovereignty. US FONOPs over the past year have been limited to challenging technical Chinese law requirements for seeking permission before transit. This new FONOP does more than that and should open the legal door to a more aggressive US challenge to China’s island-building in the South China Sea.

The most recent FONOP was conducted by the USS Decatur near the Chinese-occupied Paracel Islands (also claimed by Taiwan and Vietnam). According to the U.S. Department of Defense, the Decatur “conducted this transit in a routine, lawful manner without ship escorts and without incident…” Reports further confirm that the Decatur did not come within 12 nautical miles of any of the China-occupied islands, and the use of the term “routine” suggests the Decatur did not sail under the rules of “innocent passage.” (This last point has not been confirmed, however, by the Defense Department.) [Update, 11/4/16: In an email to the author, the Office of the U.S. Secretary of Defense confirmed that the Decatur operated “normally” and did NOT sail under innocent passage].

Although the US DOD statement does not explicitly say so, it is most likely that the Decatur’s passage was a challenge to China’s excessive straight baselines around the Paracels. [Update, 11/4/16: In an email to the author, DOD has confirmed that the Decatur FONOP was an excessive straight baseline challenge.] Because China is claiming a right to a territorial sea beyond 12 nautical miles as a result of its use of straight baselines, the Decatur entered Chinese-claimed “territorial seas” even though it did not sail within 12 nautical miles of any of the islands. This is confirmed by the Chinese government’s reaction, which described the FONOP as “uninvited entry” into China’s “territorial waters.” (To see China’s baselines on a map, look at this U.S. Department of State publication and scroll down to the last page).

States use baselines to determine where to draw the line between their coast and the beginning of their territorial sea under the UN Convention on the Law of the Sea. Under that treaty, a “normal baseline” is a “low water line along the coast” as set forth in Article 5. But under Article 7, states may use a “straight baseline” joining appropriate points (not at the low-water line) where “the coastline is deeply indented and cut into, or if there is a fringe of islands along the coast in its immediate vicinity…”

Excessive straight baselines are a common target of US FONOPs challenging territorial claims, and China is one of many countries that have, in the view of the U.S., abused this tool of maritime demarcation. In 2015, the US challenged the excessive straight baselines of three countries (China, Nicaragua, Vietnam) and in 2014 the US challenged those of seven (China, Ecuador, South Korea, Nicaragua, Iran, Vietnam and Taiwan).

In the case of China, the U.S. has long argued that China cannot simply connect straight baselines between the various small islands in the Paracels, since none of the circumstances in Article 7 apply and China is also not an archipelagic state like Japan or the Philippines (The US critique is laid out in detail here at pages 7-8).

This brings me back to my main point. Unlike the other US FONOPs in the South China Sea since October 2015, the Decatur FONOP (probably) did not follow the rules of innocent passage even though it was entering waters China claims are its territorial waters. While the US has always followed innocent passage when it sailed into other Chinese-claimed 12 nautical mile territorial seas, it did not do so here because the US government believes no country, including China, can use straight baselines to delimit a territorial sea between the Paracels (an “archipelagic straight baseline”). Put another way, the U.S. government does not accept that any country can use straight baselines to create a “territorial sea” in the way that China claims to have done in the Paracels. This amounts to a flat-out rejection of China’s claim to maritime sovereign rights.

This approach should inform a US FONOP aimed at China’s recently-built artificial islands. Just as it rejects “excessive straight baselines,” the U.S. government does not accept that any country can use an artificial island to generate a territorial sea in the way that China seems to have done at Mischief Reef in the Spratlys. Under UNCLOS Article 60, coastal states (like the Philippines) have exclusive jurisdiction to build artificial islands in their own EEZs, and artificial islands cannot generate entitlements to a territorial sea. The July 12 UNCLOS arbitral tribunal award confirmed this point, holding that China’s artificial island on Mischief Reef had no legal foundation whatsoever because it sits inside the Philippines’ EEZ. China has no legal basis (that the US would recognize) for any territorial seas around that reef. Like it has done in the Paracels, therefore, the U.S. could conduct a “routine” non-innocent passage FONOP within 12 nautical miles of Mischief Reef.

There is no legal obstacle to a US FONOP directly challenging the legal basis of China’s artificial islands. Indeed, the legal basis seems at least as strong as the challenge to the “excessive straight baselines” just conducted in the Paracels. Given the strategic problem China’s artificial islands pose to US freedom of navigation interests, it is actually surprising that the U.S. has not conducted such a FONOP yet. The legal basis existed before the July 12 arbitral award and has only become clearer since the award’s issuance. To be sure, China will not be happy with this “violation of its territorial seas.” But it is unlikely to react any more aggressively than it has just done with respect to the Decatur’s recent FONOP. A Mischief Reef FONOP is the logical next step. Whether it happens will tell us a great deal about the future scope and effectiveness of US FONOPs in the South China Sea.