China imposed a ban on fishing in contested territorial waters in the South China Sea yesterday, as its long-time battle with the Philippines over the territory heated up.

The annual ban, which has been in place every year since the 1990s, will be enforced in areas of the Philippines’ Exclusive Economic Zone, as determined by the United Nations Convention on the Law of the Sea (UNCLOS). It adds to a dispute that flared in April when Chinese civilian patrol boats prevented the Philippines navy from arresting Chinese fisherman found in the area, known as the Scarborough Shoal. Both countries have kept civilian ships in the shoal since.

Scarborough Shoal is 124 nautical miles from the Philippine coast, well within the Exclusive Economic Zone, which extends 200 nautical miles out to sea. By contrast, the Chinese coast is about 500 nautical miles from the shoal.

Australian Foreign Minister Bob Carr weighed in to the debate from Shanghai last week, saying: “We don’t take a side on the various claims over the South China Sea. But we do, given our interest in the South China Sea, and given the fact that a large proportion of our trade travels through it, we do call on governments to clarify and pursue those claims and accompanying maritime rights in accordance with international law, including the [UNCLOS].”

Chinese tourism authorities made moves to ensure that most Chinese tourists had left the Philippines (with 1500 Chinese tourists cancelling trips and airlines suspending flights), while China has also blocked some key Philippine imports in a move that will hurt the country economically.

Crikey spoke to Dr Ian Storey, editor of the Contemporary Southeast Asia journal and a senior fellow at Singapore’s Institute of Southeast Asian Studies, to get a better understanding of the conflict …

Under international law, does China or the Philippines make the strongest claim to the Scarborough Shoal?

Storey says that the Philippines’ claim to the Scarborough Shoal dates back to its independence in 1946 and is based on continuous and effective jurisdiction. “China bases its claims on history going back to the second century BC, but under UNCLOS history is not a strong card,” said Storey. “If both sides took the case to the International Court of Justice perhaps the Philippines would have the stronger case, but this won’t happen because China has ruled out international legal arbitration.”

The only other way to resolve the dispute is if both countries come to a mutually agreeable outcome, which is highly unlikely, Storey told Crikey.

Is UNCLOS toothless in territorial disputes?

“Not really,” replied Storey. “The law of the sea isn’t designed to resolve territorial disputes.”

He explained that the International Tribunal for the Law of the Sea (ITLOS) is the body that can make a ruling on maritime boundaries, but China is not bound by rulings on maritime boundaries by the ITLOS although the Philippines could ask the tribunal for an advisory ruling.

“If the political will is there, they could take the dispute to the International Court of Justice, but that requires the agreement of both parties,” said Storey.

Why is China so determined to claim these waters?

Storey says that if China could successfully claim sovereignty over the waters, it would be able to claim the corresponding economic rights.

“So that includes fishing, but more importantly it is about oil and gas. Sovereignty is also a very sensitive issue in Asia and especially in China because of the hundred years of shame, when they ceded territory,” he said.

Also known as the “century of humiliation”, this refers to a period from the mid-1800s until after World War II when China was subjugated by Western and Japanese imperial forces.

A compromise has become more difficult to achieve, says Storey, noting that: “The other issues are also maritime warfare and sea lane security, which has become much more important as 80-85% of China’s energy now comes through the South China Sea.”

Is military conflict likely?

“What’s been going on since early April is essentially a game of chicken,” Storey told Crikey. “Each side is reluctant to back down for fear of losing face. China’s international, unilateral fishing ban has come into effect in the northern South China Sea, which includes Scarborough Shoal. The Philippines have also introduced a fishing ban in areas surrounding Scarborough Shoal,” he explained.

“The bans are of questionable legality but they do provide a face-saving method for both countries; it gives both countries a chance to withdraw their vessels from the waters, thus defusing the tense situation.”

So, the current tension is likely to ease?

“Tensions in the South China Sea are cyclical and they ebb and flow,” said Storey. “The fisheries bans could diffuse the situation for the time being, although sooner or later we will see another similar incident emerge. The current stand-off at Scarborough Shoal has been going on longer than any anything since the mid-90s.”