【明報專訊】Tensions are running high over the South China Sea (南中國海) as China and its rival countries have repeatedly clashed over the islands of enormous resources. One of the points of contention (爭論) is whether the United Nations Convention on the Law of the Sea (UNCLOS,《聯合國海洋法公約》), which came into effect 21 years ago today, should be the basis for demarcating (界定) the region in question.

The UNCLOS

The UNCLOS resulted from the third United Nations Conference on the Law of the Sea, which took place between 1973 and 1982. Its importance lies with the following definitions:

(a) Internal waters (內水)

Cover all water and waterways on the landward side of the baseline (領海基線).

(b) Territorial waters (領海)

Run out to 12 nautical miles (海里) from the baseline. The coastal state is free to set laws, regulate use, and use any resource of the waters.

(c) Contiguous zone (毗連區)

A further 12 nautical miles from the territorial sea baseline limit, in which a state can continue to enforce its laws in four specific areas: customs, taxation, immigration and pollution.

(d) Exclusive economic zones (EEZs, 專屬經濟區)

Extend from the edge of the territorial sea out to 200 nautical miles from the baseline. Within this area, the coastal nation has sole exploitation rights over all natural resources.

(e) Continental shelf (大陸架)

Defined as the natural prolongation of the land territory to the continental margin's outer edge, or 200 nautical miles from the coastal state's baseline, whichever is greater.

◆South China Sea sovereignty disputes

The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from Singapore and Malacca Straits (馬六甲海峽) to the Strait of Taiwan of around 3,500,000 square kilometres.

In dispute are four groups of islands in the South China Sea:

The Pratas Islands (東沙群島): Consist of three islets. Controlled by Taiwan.

The Spratly Islands (南沙群島): Consist of more than 750 reefs, islets, atolls, cays and islands. Currently occupied by mainland China, Taiwan, Vietnam, the Philippines and Malaysia.

The Paracel Islands (西沙群島): Include about 130 small coral islands and reefs. Have been occupied by mainland China since a sea battle between China and Vietnam in 1974.

The Zhongsha Islands (中沙群島): The whole region is claimed by the mainland and Taiwan authorities, and various bits of the western parts are claimed by the Philippines. Scarborough Shoal (黃岩島), the largest of the islands, is currently controlled by Beijing.

◆The UNCLOS and the nine-dash line: which should prevail?

Beijing has laid claims to all the above-mentioned islands. Its claim is vigorously challenged by the governments of Taiwan, the Philippines, Malaysia, Vietnam etc.

Beijing insists that its claim is solidly based on historical and legal evidence. It argues that the nine-dash line (九段線), which encloses all islands mentioned above, is borne out by such evidence and should be the basis for settling the disputes. However, countries like the Philippines believe that the UNCLOS gives them sovereignty over some islands, for example Scarborough Shoal, which lies within the Philippines' EEZ. Beijing responds by arguing that its sovereignty over the region had begun long before the UNCLOS came into existence.