By Jay L. Batongbacal

Atoll in the Spratly Islands. Source: Storm Crypt’s flickr photostream, used under a creative commons license.

As the December 15 deadline for China to submit a counter-memorial in the UN Convention on the Law of the Sea (UNCLOS) Annex VII arbitration case launched by the Philippines passed, the more significant and unexpected development turned out to be Vietnam’s discreet submission of a formal statement to the tribunal. The South China Morning Post reports that Vietnam asked the tribunal to give due regard to Vietnam’s legal rights and interests that may be affected by the arbitration. Vietnam also stated its support for the tribunal’s jurisdiction over the case, and its rejection of China’s claim to the islands and waters of the Spratly and Paracel islands, as well as historic rights within the area enclosed by the nine-dashed line, as illegal. Carl Thayer also says that the statement opens “the back door” for Vietnam to make a presentation of its rights and interests.

The Philippines has officially welcomed Vietnam’s move as promoting the rule of law and regional peace and stability, and subsequent reports zeroed in on the value of a common legal position against China’s nine-dashed line claim. But while the statement’s political significance cannot be discounted, its legal impact may not be as clear-cut for the Philippine case.

It is important to note that Vietnam officially reiterated that it “has full historical evidence and legal foundation to reaffirm its sovereignty over the Hoang Sa [Paracels] and Truong Sa [Spratlys] archipelagoes, as well as other legal rights and interests…in the East Sea.” While Vietnam has brought its maritime jurisdictional claims into conformity with UNCLOS, it has not relinquished its claims to sovereignty over all the islands and features in the Spratly Island group.

Vietnam’s statement apprises the tribunal of its own claims to the islands and other features within the area of the dispute, and places a greater onus on the Philippines to demonstrate that its claims can be granted without regard to the competing claims to sovereignty made by other states. The problem arises on account of the proximity of Vietnam’s occupied islands and rocks in the Spratly area, particularly around the Chinese positions on which the Philippines has asked the tribunal to rule.

Map of the Spratly Islands region. Dark blue lines represent the 200M EEZ/CS of Vietnam and the Philippines. Vietnamese-occupied islands (triangles) and rocks (squares) in orange, Philippine-occupied islands and rocks in bright blue. Chinese-occupied rocks and submerged reefs (circles) positions indicated in red. The yellow line is a 200M radius around Itu Aba, the largest island in the area. The shaded area is the extended continental shelf area jointly claimed by Vietnam and Malaysia. The southern tip of Palawan, Philippines is visible on the lower right corner. Image created by Jay Batongbacal.

Of those features, Johnson South and Gaven reefs are within 12 nautical miles of an occupied rock or island that can potentially generate at least a territorial sea; Cuarteron, McKennan, and Subi reefs appear to be outside such zones but are close enough to warrant actual surveys before a definitive pronouncement can be made. Only Mischief Reef and Fiery Cross Reef stand far enough away from any adjacent feature as to be clearly outside any potential 12 nautical mile territorial sea generated by a nearby island or rock, whether Vietnamese- or Philippine-occupied.

The problem for most features is that the claims that the Chinese facilities are illegal are premised on their being located on the Philippine EEZ and continental shelf; if they are in fact within a maritime zone that is potentially Vietnamese, then it may be difficult for the tribunal to grant the Philippine claim without adversely affecting the Vietnamese claim in that particular location. It should also not be forgotten that all these Chinese-held installations are within a 100 nautical mile radius of at least one of the largest occupied islands of Itu Aba (Taiwan), Pagasa (Philippines), and Spratly (Vietnam). The fact of proximity to other features underlines a key jurisdictional objection of China, so the Philippines must successfully argue that its claims against the Chinese installations may be granted without undertaking maritime boundary delimitation because no EEZ/continental shelf zones are generated by these largest islands.

Contrary to some reports, Vietnam did not ask to join the proceedings, and there is actually no provision for intervention in the tribunal’s rules of procedure. But the questions above may actually necessitate formal intervention; otherwise, much of the Philippine case might be jeopardized should the tribunal determine that most of the claims cannot be properly litigated without Vietnam. However, this might prolong the arbitration and at the same time risk setting the Philippines against Vietnam with respect to certain aspects of their own contending claims in the Spratly Islands.

Nonetheless, it appears that the Philippines’ remaining claims in the case, particularly those concerning the nine-dashed line and Scarborough Shoal, may be sufficiently removed from these considerations. The outcome will therefore depend on how well the arguments are made concerning the nature of the nine-dashed line and the manner in which they have been asserted. It will also require the Philippines to make a greater effort to separate the issue of the legality of the nine-dashed line from those of the legality of the Chinese-occupied positions. On this score, Vietnam’s position may help the Philippine case.

Mr. Jay L. Batongbacal is Assistant Professor, University of the Philippines College of Law, and Director, University of the Philippines Institute for Maritime Affairs and Law of the Sea. He is on leave and affiliated with the East West Center in Washington D.C. as a U.S.-ASEAN Fulbright Initiative Visiting Scholar, doing research on evolving US maritime security policies and their impact on the resort to international arbitration and the Rule of Law in the South China Sea disputes.