TERRITORIAL disputes in the South China Sea have long been regarded as one of Asia's potential flashpoints. The main claimants of the four large island groups in the area are China, Vietnam and the Philippines. Malaysia and Brunei also have claims, but these involve much smaller areas.
How should these disputes be resolved?
The United States said recently that China should base its claims on the United Nations Convention on the Law of the Sea (Unclos), rather than the so-called nine-dash line that it uses to delineate its claims. This line extends 1,800km from the Chinese mainland, and includes all four disputed island groups.
Unclos is the universally accepted framework governing all uses of the oceans. Thus, it is the treaty law that covers competing claims over stretches of water.
But it does not address competing claims to sovereignty over land, which are governed instead by customary international law, that is, law governing the relations between or among states that has been received down the ages as a custom, like a war of aggression is unlawful, much of which is not written into formal treaties.
This suggests that China's claims to the disputed islands based on history, while dismissed by many Western commentators, may have a basis in international law.
Land first, then seas
BUT first, a closer look at Unclos.
A key Unclos tenet is that a coastal state is entitled to various ocean or maritime zones measured from its shores. A coastal state has rights over its maritime zones only because it owns the land that generates those zones.
So, the issue of which state owns the land that generates particular maritime zones is a crucial one. And how does international law determine who owns disputed land? Here, history matters.
Thus, the Falklands are merely 1,898km from Buenos Aires, compared with 12,656km from London, Britain has claimed them since 1833. It is not always proximity to the nearest coastal state that determines who owns a particular island. The island's history matters. It is in such a context that one can begin to see some logic to China's position. China claims historic rights to the disputed islands in the South China Sea.
"Historic rights", a term used widely in international law, arguably comes under "matters not regulated by this convention", as the Unclos preamble notes.
If Unclos is not the right law to adjudicate arguments over historic rights, what is? The answer is customary international law.
One way forward for China, according to National University of Singapore law professor Alan Tan Khee-Jin, would be to first identify clearly its sovereignty claims over the islands within the nine-dash line, and then mount an argument to justify those claims based on history. Those islands would then generate maritime zones to which China would stake its claim under Unclos. Where these zones overlap with those of other claimants, they would be divided according to Unclos rules.
Dissecting China's claims
A CLOSER look at China's claim of historic rights is pertinent.
China calls the four island groups Dongsha (Pratas), Xisha (Paracel), Zhongsha (Macclesfield Bank) and Nansha (Spratly). China claims these islands by discovery, occupation, ownership and control since time immemorial.
According to Shanghai Jiao Tong University law professor Julia Xue Guifang in an interview with The Straits Times, China has ample documented evidence of its long and consistent involvement with these islands. Prof Xue has personally viewed ancient government records of the Han Dynasty (206BC-AD220) showing claims to the Nan Hai (Southern Seas) Islands. These records show that Nan Hai "barbarians" were paying tribute to China's emperor before the third century AD. Thus, very long ago, the islands acknowledged themselves to be tributaries of the Chinese empire.
One of the earliest extant works documenting the evidence is the two-volume Zhu Fan Zhi (Record of Foreign Peoples), compiled from 1225 to 1242 by Zhao Rushi of Southern Song Dynasty.
Its ancient maps provide the locational coordinates of Xisha and Zhongsha. Thus, China showed by its actions, words and visual aids that it has long considered the Nan Hai Islands its territory.
The earliest external evidence is a 1912 map produced by the British admiralty, in which the islands are clearly stated to be China's.
In modern times, the earliest internal evidence is a Chinese map of 1914, with an 11-dash line encompassing the islands. The line looks like the median between the coasts of neighbouring states and the islands in question. Prof Xue feels that the line was China's way of asserting its territorial claims to the islands.
China officially confirmed that line in 1947, when many states were clamouring for sovereignty over the continental shelf adjacent to their land. The move followed on the heels of President Harry Truman's 1945 claim of the continental shelf for the United States.
After Vietnam and China came to a border agreement in 1953, two dashes were removed from the Gulf of Tonkin, thus producing today's nine-dash line.
Significantly, from 1914 to 2009, no state protested against China's claim to the islands through its 11- or nine-dash line.
Whereas China's claim to the islands is timeless, the same cannot be said of some other countries' claims in the region.
Take the Philippines, which first staked its claim in 1971, arguing that Nansha was terra nullius after World War II.
But China's dispensing with France's 1933 claim (of Nansha for Vietnam) suggests that this Filipino claim would be unmeritorious as China never abandoned Nansha after 1933 or WWII.
Next, in 2009, the Philippines made a claim for Scarborough Shoal in Zhongsha, arguing that it had effectively occupied the islands since 1946. It argued that Spain had discovered and included the Shoal within Filipino territory in the 18th century.
But the Treaty of Paris 1898, by which Spain ceded all Filipino territory to the US, did not include these islands, so it is arguable if this claim has any merit.
ASSUMING China has historic rights to the islands, what is the legal status of the waters enclosed by the nine-dash line?
This would be governed by Unclos, under which the seas extending from the shore for 12 nautical miles are called "territorial seas". Then, there is the exclusive economic zone (EEZ) extending for 200 nautical miles from the shore, and beyond the EEZ is the continental shelf (or insular shelf for islands) for up to 350 nautical miles from the shore.
According to Unclos, land ownership generates rights over the seas. So, if China owns an island, then the 12 nautical miles of waters from its shores would comprise China's "territorial seas" over which it has absolute sovereignty.
Beyond these would be the island's EEZ, in which China would have pre-eminent or sovereign economic rights over the exploration and use of marine resources.
Beyond EEZ is its insular shelf, where China may exploit any resources, for which it must pay royalties to the Unclos-established International Seabed Authority.
Under Unclos, overlapping maritime zones of adjacent states are generally divided by an equidistant middle line.
Prof Tan adds: "However, international courts have, at times, adjusted the line between a mainland coast and a small island to reflect the different lengths of the respective coastlines. This adjustment gives the mainland the greater share of the maritime zone concerned."
Non-China claimants make their bids by Unclos rules, and they urge China to do the same.
Prof Xue agrees that China should indeed do so, but also take up its case under customary international law as well.
However, before something attains the status of customary international law, Prof Tan notes, it has to be held up by the practice of "particularly the most relevant states, those with the largest stakes in the question. And these states must do so not merely out of convenience, habit or expediency, but because they believe it is their legal obligation to do so".
Therefore, China must now convince the other claimants of its historic rights to the islands under customary international law, and then their respective maritime zones under Unclos.
While that thorny issue is being negotiated, joint exploration of disputed zones is permitted under Unclos without sovereignty being ceded.