The core issue of the South China Sea dispute is China’s unlawful claim to maritime areas beyond what the United Nations Convention on the Law of the Sea (Unclos) allows. Under China’s nine-dash line, five Asean coastal states—the Philippines, Vietnam, Malaysia, Brunei, and Indonesia—will lose large areas of their exclusive economic zones (EEZs) guaranteed to them as their inherent right under Unclos. As coastal states, these Asean five are entitled to EEZs ipso facto or by the mere fact that they have a land mass facing the South China Sea.
The Philippines stands to lose in the West Philippine Sea a maritime area larger than its total land area. Vietnam will become an almost land-locked state because China’s nine-dash line runs through the entire length of Vietnam’s coastline facing the South China Sea. Brunei will become a totally land-locked state and will lose a maritime area larger than its land area.
Unclos allows a coastal state to claim a maritime zone not exceeding 350 nautical miles from its coastline. China is claiming up to 1,000 nautical miles from its coastline in Hainan Island, even claiming the high seas of the South China Sea. Under Unclos, the high seas are the common heritage of mankind, belonging to no state.
Now, China is threatening to declare an air defense identification zone or Adiz in the airspace above the vast maritime area enclosed by its nine-dash line, comprising 85.7 percent of the South China Sea. China needs a triangle of air and naval bases within this huge maritime area to enforce its Adiz. China already has air and naval bases in the Spratlys and the Paracels. China needs to put up an air and naval base in Scarborough Shoal to effectively enforce its Adiz.
Scarborough Shoal is now at the center of the South China Sea dispute. This shoal is named Panacot in the 1734 Velarde-Bagay-Suarez map, an official Spanish map showing Philippine territory in 1734. The shoal also appears as B. Masinloc in the 1899 Jose Algue map, the first official map of Philippine territory released by the US Coast and Geodetic Survey in Washington DC during the American regime. There is no older map from China showing that Scarborough Shoal is Chinese territory. The first Chinese map showing Scarborough Shoal is the infamous 1947 nine-dash-line map of China, and even this map only shows the shoal as a dot without a name.