The territorial dispute in the Spratlys
There are two kinds of dispute in the Spratlys, the territorial dispute and the maritime dispute. The territorial dispute involves the issue of sovereignty over the geologic features above water at high tide and their surrounding territorial seas. The maritime dispute involves the economic right to exploit the resources in the waters and seabed beyond the territorial seas.
The maritime dispute has been resolved with finality by The Hague arbitral tribunal in the South China Sea Arbitration. The territorial dispute, however, remains outstanding.
The Philippines should now invite the states involved in the territorial dispute in the Spratlys to submit the dispute to a binding voluntary arbitration before the International Court of Justice. Under the UN Charter, territorial disputes must be settled peacefully by negotiation, then by mediation, and if still unresolved, then by arbitration. The territorial dispute in the Spratlys has been festering since the 1970s and it is high time to settle the dispute through voluntary arbitration. The parties to the territorial dispute are China, Vietnam, the Philippines, Malaysia, and Brunei. The Philippines should initiate now the Spratlys Arbitration because, like in the South China Sea Arbitration, the Philippines has a very strong case.
First, the Philippines has the oldest documentary evidence of sovereignty over the Spratlys—the 1734 Murillo Velarde map showing that the official territory of the Philippines during the Spanish colonial regime included the Spratlys, then called Los Bajos de Paragua. There is no older map from China, Vietnam, Malaysia, or from any other country, showing that the Spratlys formed part of their territory.
Second, under the 1898 Treaty of Paris as amended by the 1900 Treaty of Washington, Spain ceded the Spratlys to the United States. The Treaty of Washington states that Spain also ceded to the US “all title and claim of title, which (Spain) may have had xxx to any and all islands belonging to the Philippine Archipelago xxx lying outside the lines” of the Treaty of Paris. The frame of reference of the phrase “all islands belonging to the Philippine Archipelago xxx lying outside the lines” is the 1734 Murillo Velarde map, which showed the Spratlys as part of Philippine territory. All states involved in the territorial dispute have recognized the Treaty of Paris and the Treaty of Washington, with China even mentioning these treaties with approval in its official communications.
Third, the 1657 map of the Philippines made by Nicolas Sanson clearly shows the Spratlys as part of Philippine territory. Sanson was the Royal Cartographer of King Louis XIII of France. When France annexed the Spratlys in 1933, France knew that the Spratlys were no longer terra nullius. Besides, Vietnam cannot use the 1933 French annexation because France annexed the Spratlys not as part of its Indochina colony but as part of the overseas territories of the French Union, whose inhabitants are French citizens who could vote in all French elections.
Fourth, China can no longer use the notorious nine-dash line to claim the Spratlys because these lines have been exposed as without legal or factual basis in the South China Sea Arbitration. China first claimed the Spratlys only in 1947 when it released officially within China its nine-dash line map. China is a late claimant, and a late occupant, to the Spratlys.
Fifth, under the international law doctrine of uti possidetis, the boundaries of colonies are sacrosanct and could not be changed to the prejudice of the independent states that emerged from those colonies. Thus, in the Mauritius case, the United Nations General Assembly, following the legal opinion of the International Court of Justice, voted 116-6 last May 22, 2019, that the United Kingdom should return the Chagos Archipelago to Mauritius. The Chagos Archipelago was detached from Mauritius by the UK prior to the independence of Mauritius. Similarly, the Spratlys cannot be detached from the Philippines since the Spratlys were part of Philippine territory during the Spanish and American colonial regimes.
If the other claimant states reject the request of the Philippines for voluntary arbitration, then the Philippines can just wait for sea level rise to submerge the Spratlys in the next 100 years. The submerged areas will then form part of the exclusive economic zone of the Philippines.