Illustration: Liu Rui/GT

For many years, the People's Republic of China has been a strong supporter of the UN Convention on the Law of the Sea (UNCLOS). Recently, however, China's experience has been that the Convention and, in particular, its provisions on compulsory dispute settlement, may be exploited by other states for political reasons.

Knowing full well that disputes over territorial sovereignty and maritime delimitation do not fall under the UNCLOS dispute settlement mechanisms, the Republic of the Philippines, in an act of legal warfare ("lawfare"), nevertheless instituted arbitration proceedings against China before a UNCLOS Annex VII arbitral tribunal with regard to the disputes between the two countries in the South China Sea.

During the negotiations on the Convention in the 1970s, China raised concerns about the dispute settlement provisions, which it considered "inappropriate," and argued that the provisions should not be included in the Convention itself.

China's suggestion was that the provisions should form a separate protocol so that countries could decide for themselves whether or not to accept compulsory dispute settlement.

By way of compromise, it was agreed that certain disputes would not be included in UNCLOS's compulsory dispute settlement mechanisms and that others could be removed by express declaration of states parties.

The latter included disputes relating to sea boundary delimitation, historic titles, sovereignty or other rights over continental or insular land territory, military activities and law enforcement activities. China duly made use of this opportunity on August 25 2006 when it excluded all of these disputes from the compulsory dispute settlement mechanisms under UNCLOS.

According to Article 288(4) of UNCLOS, it is not, however, the contracting party but rather the arbitral tribunal that determines whether a dispute exists and defines its content.

This holds considerable risks and uncertainties for the parties, especially in case of tribunals that engage in judicial activism, as was demonstrated by the Tribunal's Award on Jurisdiction and Admissibility of October 29 2015 in the South China Sea Arbitration.

While the Tribunal accepted that a dispute in international law requires that there be "positive opposition" between the parties, it did not, and could not, establish such opposition and, instead, established a dispute "by inference."

What is, in fact, a dispute on territorial sovereignty and maritime delimitation was redefined by the Tribunal as a dispute concerning the status of maritime features and the source of maritime entitlements, questions on which, as the Tribunal rightly noted, China had never expressed a detailed position. If the Arbitral Tribunal in its Award on the Merits, which is expected later in 2016, decides this "dispute" in a way that infringes China's territorial sovereignty over the Nansha Islands, China might consider denouncing the Convention.

According to Article 317 of UNCLOS, a state party may denounce the Convention by written notification to the Secretary-General of the UN and may indicate its reasons. Such a denunciation would take effect one year after the date of receipt of the notification.

While China would not be discharged by reason of the denunciation from obligations that accrued while it was a party to the Convention, it would be protected against similar future claims brought by Vietnam, Indonesia or Malaysia with regard to the South China Sea, or by Japan with regard to the East China Sea.

Would there be any serious disadvantages for China if it denounced UNCLOS? The short answer is: no. China would continue to enjoy most of the advantages of UNCLOS because today the majority of its provisions are considered to be part of customary international law. The only exceptions are the provisions on the Area, i.e. deep seabed mining (Part XI), the development and transfer of marine technology (Part XIV) and the provisions on the compulsory settlement of disputes (Part XV).

The US, for example, has not been a contracting state of the Convention for the last 33 years and has not suffered any serious problems. On the contrary, it enjoys most of the advantages under the Convention such as freedom of navigation and overflight, the rights of the Exclusive Economic Zone and the continental shelf without carrying any of the burdens.

China would no longer have a judge on the International Tribunal for the Law of the Sea and would no longer be represented on the Commission on the Limits on the Continental Shelf. It could also no longer be a member of the International Seabed Authority.

China could probably lay claim to an outer continental shelf and its resources under customary international law but its energy companies would be excluded from the exploration and exploitation of the Area, unless registered and sponsored by another contracting party.

Whether China ultimately wants to continue to be a party to UNCLOS should be the result of a legal and political cost-benefit analysis. The Convention itself opens the way for China to leave the Convention and it would have good reasons to do so if its territorial sovereignty was undermined by a decision of an arbitral tribunal established under the Convention.

The author is director of the Institute of Public International Law at the University of Bonn and a Supernumerary Fellow of St Anne's College, Oxford. opinion@globaltimes.com.cn