Testing the rule of law in the South China Sea

How China reacts to the sweeping legal defeat over its claims to the South China Sea will tell the world a lot about its approach to international law, the use — measured or otherwise — of its enormous power, and its global ambitions. So far, the signs are troubling. Beijing has defiantly rejected an international arbitration court’s jurisdiction over a case brought by the Philippines and insisted it will not accept Tuesday’s pathbreaking judgment.

The unanimous ruling, by a fivejudge tribunal in The Hague, was more favorable toward the Philippines and broader in scope than experts had predicted. It said that under the United Nations Convention on the Law of the Sea, China had no legal basis to claim historic rights over most of the waterway, which is rich in resources and carries $5 trillion in annual trade.

The panel also faulted China for its aggressive attempts to establish sovereignty by shipping tons of dirt to transform small reefs and rocks into artificial islands with airstrips and other military structures. China’s neighbors fear that it intends to use these outposts to restrict navigation and the rights of others to fish and explore for oil and gas.

The Philippines filed the case in 2013 after China took control of a reef known as Scarborough Shoal. The case accused Beijing of interfering with fishing, endangering ships and failing to protect marine life. Manila also asked the tribunal to reject China’s claims to sovereignty within a so- called ninedash line that encompasses much of the South China Sea and appears on official Chinese maps.

The judges ruled for the Philippines on most claims in its complaint: China had indeed violated international law by causing “irreparable harm” to the marine environment, endangering ships and interfering with Philippine fishing and oil exploration. Further, China had illegally built an artificial island on Mischief Reef, complete with a military airstrip, in waters belonging to the Philippines.

The Law of the Sea treaty sets rules for establishing zones of control over the oceans based on distances to coastlines. In addition to China and the Philippines, Malaysia, Vietnam, Brunei, Indonesia and Taiwan all claim parts of the South China Sea. The tribunal is authorized to deal with maritime disputes, not the underlying land claims to the islands, reefs and rocks that are also contested. The decision is the first international ruling on the disputed maritime issues in the South China Sea.

There are serious concerns about what will happen next. The tribunal has no authority to enforce its ruling, and China, which boycotted the legal process, threatens to use force to protect the maritime interests the court has now declared illegal.

What this means in practice is not clear. Given China’s stake in peaceful trade with the rest of the world, it would be foolish for President Xi Jinping to take provocative actions that could inflame regional tensions and conceivably lead to a military confrontation with its neighbors or the United States.

Retaliatory measures — further islandbuilding at Scarborough Shoal, for instance, or declaring an air defense zone over large portions of the South China Sea — would be risky.

In fact, the ruling offers a fresh opportunity to address maritime disputes in a peaceful manner. China’s ambassador to the United States, Cui Tiankai, condemned Tuesday’s ruling but said Beijing remains open to negotiations. Nations in the region have often gone wobbly in the face of pressure from Beijing. At this critical moment, despite competing interests of their own, they need to join the Philippines in endorsing the tribunal decision and then proceed, if necessary, with their own arbitration cases.

The United States, which is neutral on the various claims, can help ensure a peaceful, lawful path forward. The Obama administration has said that disputes should be resolved according to international law, a position it now reaffirms. It has built closer security relations with Asian nations and responded to China’s assertiveness in the South China Sea with increased naval patrols. This combination of diplomacy and pressure is sound, but the hard part is getting the balance right.