In what is a major blow to China, the Arbitral Tribunal that ruled on the case brought by the Philippines against China's claims in the South China Sea has invalidated the "nine-dash line" on which these claims are based.
In its award released yesterday, the United Nations-backed tribunal found China's claim to "historic rights" to resources within the line to be incompatible with the allocation of rights and maritime zones under the UN Convention on the Law of the Sea (Unclos).
Any historic rights China might have to resources in the waters "were extinguished" when Unclos came into force, in 1994, it said.
Any claims China makes in the South China Sea must be made based on maritime entitlements from land features, it added.
China's nine-dash line first came to international notice in 2009 when Beijing made a submission to the United Nations stating its claims to islands in the South China Sea, accompanied by a map with nine dashes that extend from its Hainan island, south to Borneo and northwards to Taiwan, in a U-shape.
Based on a 1940s map drawn by the Kuomintang government of China, it encompasses almost the entire sea and overlaps with the territorial claims of four Asean states, including the Philippines, as well as Taiwan.
China has been ambiguous about the nine-dash line - no coordinates are given for it and Beijing has refused to define what it is claiming within that line despite calls from various quarters to do so.
The tribunal said it had examined historical records to determine whether China had indeed rights to resources in the sea before Unclos came into force.
It found that while navigators and fishermen from China and other states had historically made use of the islands in the South China Sea "there is no evidence that China had historically exercised exclusive control over the waters of the South China Sea or prevented other states from exploiting their resources".
It concluded, therefore, that there is no legal basis for China to assert such historic rights to the resources within the sea areas falling within the nine-dash line.
China's claim is further invalidated by the tribunal's ruling on the features that China claims in the Spratlys, which it found to be rocks or low-tide elevations and, therefore, not entitled to an extended maritime zone - that is, a 200-nautical- mile exclusive economic zone within which a state has the right to explore and use the resources.
China has said it will not recognise the ruling and analysts expect that it will continue to adhere to the nine-dash line to exercise what it sees as its maritime and sovereign rights within the line.
"It will still regard the nine-dash line as a line that allows China to exercise its historical rights," said Associate Professor Li Mingjiang of the S. Rajaratnam School of International Studies.