The Philippines has been widely applauded for bringing the first ever arbitration case relating to the South China Sea disputes before an UNCLOS Arbitration Tribunal, but it still needs to clear the three hurdles of jurisdiction, admissibility and merit. In other words, Manila needs to prove that its case falls within the Tribunal’s jurisdiction, that there is nothing to disqualify the case, and, finally, that the complaints therein should be upheld. There is little doubt that China’s various claims over the maritime expanse roughly defined by its infamous Nine-Dash Line violate international law of maritime delimitation, but it is nonetheless far from certain that the Philippines will clear all three hurdles for all of its claims.
First line of defence
Although China has boycotted the legal proceedings, it has indirectly delivered its arguments to the Tribunal by publishing a paper laying out its arguments. These arguments deploy three main lines of defence that focus on the first two hurdles, jurisdiction and admissibility.
First, China argues that:
[t]he essence of the subject-matter of the arbitration is the territorial sovereignty over several maritime features in the South China Sea, which is beyond the scope of the Convention and does not concern the interpretation or application of the Convention;
UNCLOS accords the Tribunal jurisdiction to answer questions that relate to the interpretation and application of the Convention, and it is generally accepted that this does not include those whose essence is territorial sovereignty. Any of the Philippines’ claims which fall foul of this condition will be outside the jurisdiction of the Tribunal.
In reality, this line of defence is misplaced. What the Philippines claims is that Scarborough Reef and the Spratlys are either not islands, or they are islands that are not entitled to an exclusive economic zone (EEZ). The essence of this claim is physical geography, not territorial sovereignty. For features that are naturally submerged at high tide and are more than 12 nautical miles from islands, territorial sovereignty does not even exist. For those that are naturally above water at high tide, whether they are entitled to an EEZ or not depends on interpretation and application of UNCLOS’s Article 121(3), which has nothing to do with territorial sovereignty, and is therefore completely within the jurisdiction of the Tribunal. The Philippines’ summary of its case at the hearing on jurisdiction and admissibility alludes to the use of these arguments to bypass China’s first line of defence:
… the various maritime features relied upon by China as a basis upon which to assert its claims in the South China Sea are not islands that generate entitlement to an exclusive economic zone or continental shelf. Rather, some are “rocks” within the meaning of Article 121, paragraph 3; others are low-tide elevations; and still others are permanently submerged. As a result, none are capable of generating entitlements beyond 12M, and some generate no entitlements at all.
Second line of defence
China further argues that:
Even assuming, arguendo, that the subject-matter of the arbitration were concerned with the interpretation or application of the Convention, that subject-matter would constitute an integral part of maritime delimitation between the two countries, thus falling within the scope of the declaration filed by China in 2006 in accordance with the Convention, which excludes, inter alia, disputes concerning maritime delimitation from compulsory arbitration and other compulsory dispute settlement procedures;
If Scarborough Reef or some of the Spratly features are entitled to an EEZ, then there will be an overlap of this EEZ entitlement and the EEZ entitlements of Palawan and Luzon. If that were the case, and if the Philippines had asked the Tribunal to divide up the area of overlapping entitlements, that would have been a matter of maritime delimitation, and the Tribunal would not have jurisdiction to do so.
In reality, China’s second line of defence is also misplaced. The Philippines’s claim regarding Scarborough Reef and the Spratlys, namely that:
… some are “rocks” within the meaning of Article 121, paragraph 3; others are low-tide elevations; and still others are permanently submerged. As a result, none are capable of generating entitlements beyond 12M, and some generate no entitlements at all.
is not about delimitation but about interpretation and application of UNCLOS’s Article 121(3), which, as stated earlier, is entirely within the jurisdiction of the Tribunal.
The Philippines’ case also includes two other substantial claims, neither of which is affected by China’s first two lines of defence:
… China is not entitled to exercise what it refers to as “historic rights” over the waters, seabed and subsoil beyond the limits of its entitlements under the Convention;
… China has irreversibly damaged the regional marine environment, in breach of UNCLOS, by its destruction of coral reefs in the South China Sea, including areas within the Philippines’ EEZ, by its destructive and hazardous fishing practices, and by its harvesting of endangered species.
Third line of defence
Finally, China argues that:
China and the Philippines have agreed, through bilateral instruments and the Declaration on the Conduct of Parties in the South China Sea, to settle their relevant disputes through negotiations. By unilaterally initiating the present arbitration, the Philippines has breached its obligation under international law;
If the Philippines has a legal obligation not to take China to court, this case will be inadmissible.
The article of the Declaration of Conduct (DOC) that China refers to states that:
The Parties concerned undertake to resolve their territorial and jurisdictional disputes by peaceful means, without resorting to the threat or use of force, through friendly consultations and negotiations by sovereign states directly concerned, in accordance with universally recognized principles of international law, including the 1982 UN Convention on the Law of the Sea;
In practice, both China and ASEAN, as well as senior Chinese scholars, have taken the view that the DOC does not give rise to legal obligations. Furthermore, given China’s strident assertion of “indisputable sovereignty” and its policy of not negotiating the sovereignty issue, which it terms the “essence of the subject matter”, it is disingenuous for Beijing to claim that the only means available to the Philippines for settling territorial and jurisdictional disputes is negotiation. If the Tribunal agrees with that disingenuous argument, it will condemn the Philippines to an absurd predicament: no recourse but to negotiate resolution of the disputes with a country that does not negotiate but, instead, uses paramilitary forces to seize control. Therefore it would be extremely unfair for the Tribunal to uphold China’s third line of defence.
Dilemma and risk
In summary, China’s three lines of defence are unlikely to stop the Philippines’ case at the hurdles of jurisdiction and admissibility.
If this turned out to be true, China would face a serious dilemma. It could continue to boycott the legal proceedings, but its justification for the boycott in terms of lack of jurisdiction and inadmissibility would have been proven false already. Furthermore, continuing to deliver its arguments via the court room’s window by publishing “position papers” is not a dignified course of action for a superpower. Alternatively, Beijing could come inside to argue its case, which would be a step down from its current position, and, more importantly, would make it even harder for it to disregard rulings that go against it.
For the Philippines, even if its case cleared the hurdles of jurisdiction and admissibility, there is still a major risk at the merit hurdle.
The Philippines’ rejection of “historic rights” as a basis for claims over the maritime space inside the Nine Dash Line seems well-founded in law. Its claim regarding the marine environment also seems strong, especially considering China’s massive island-building projects on coral reefs since 2014.
However, the heart of the Philippines’ case, and where the greatest risk lies, is the claim that the Spratlys and Scarborough Reef are not entitled to EEZs. There is little doubt that the Tribunal will uphold this claim for Scarborough Reef, which only has a few rocks above high tide. The Spratlys, on the other hand, include a handful of islands that range in size from 0.1 to 0.5 km², and it has never been determined in court whether or not UNCLOS’s Article 121(3) denies such islands an EEZ. In analogous cases, international courts and Tribunals were able to take advantage of maritime delimitation principles to ignore such islands without having to interpret and apply this article, so it has remained a grey area. Not having the jurisdiction to apply maritime delimitation principles, this Tribunal will have little choice but to embark on an interpretation of this controversial article. If it ruled that this article applies to the Spratlys, the disputed waters in that area would be restricted to 12 nautical miles around the islands, which would improve the regional security situation enormously. If not, South China Sea would be condemned to ever more turmoil, confrontations, and the threat and use of force until, quite possibly, China’s military might allows it to impose its will on the other littoral states.
 “A legal analysis of China’s historic rights claims in the South China Sea”, Dupuy and Dupuy, American Journal of International Law, Vol 107:124