The legal process begun by the Philippines to challenge claims by China to the South China Sea surprised the region. International arbitration is allowed under the UN Convention on the Law of the Sea, but the move adds urgency and new elements to a trying political scene.
Relations between the two nations over competing claims have been tense in the past year, with vessels standing off for months near Scarborough Shoal. The issue also affected Asean unity last year, when then chairman Cambodia could find no compromise wording for an official statement.
What does this new move portend? At first glance, it is a legitimate step, supported by the various calls for parties to use international law, rather than force. China has accepted the UN convention and now faces a difficult choice.
Arbitration for this sea treaty is compulsory and a timeline will unfold in the coming weeks in which the International Tribunal for the Law of the Sea will require arbitrators to be nominated and a schedule set out for the case. If Beijing refuses to participate, these proceedings can still go ahead without it.
If China does take part, it can challenge the questions that can be addressed. The scope of jurisdiction in this particular provision is limited and cannot include issues like sovereignty over the rocks.
Even if China participates and loses, it can refuse to comply and there will be no penalties or police to enforce the ruling. Global public opinion could, however, be affected. Manila's legal move must therefore be seen in a broader political context.
Some Chinese will suspect a conspiracy or concert against them. The United States' rebalancing to the region has co- incided with the resurgence of the long-standing disputes in the South China Sea. Philippine President Benigno Aquino has invited American forces to consider arrangements to visit his country for extended periods. This is in sharp contrast to the past Corazon Aquino administration that ordered the closure of US bases.
Japan's role will also be questioned. Representing the new Shinzo Abe administration, Foreign Minister Fumio Kishida chose Manila as his first overseas visit. There, he promised to provide coast guard vessels and found a welcome for the idea that Japan should re-arm.
This comes amid increased tension between Tokyo and Beijing over the Senkaku/Diaoyu Islands. Some will therefore question the coincidence that the legal challenge has come so soon after the visit. Another coincidence is that the tribunal for the law of the sea has a Japanese national as its president - Shunji Yanai - although he is not under instruction from Tokyo.
It is therefore for the better that steps be taken to stabilise relations. The new Chinese Communist Party chief, Xi Jinping , has called for co-operation to handle "sensitive" issues effectively and in a timely manner. This came when China received Natsuo Yamaguchi, leader of the New Komeito party, the junior coalition member in the current government.
The future tenor of US-China ties is harder to read as key appointments to the state and defence departments are still pending and new Chinese leaders are settling in. President Barack Obama did, however, set clear priorities in his inaugural address that focus on domestic issues. Moreover, having trumpeted the coming end to a decade of war, Obama should be cautious about engaging in potential Asian conflicts, even if allies wish otherwise.
In this context, it is critical that the Association of Southeast Asian Nations maintains its neutrality. Although the Philippines is a member of the group, others in Asean - whether collectively or individually - were not consulted on the legal challenge. The Singapore government, for example, has said it first heard about it through the media. Manila's right to take this route was also acknowledged as its own national decision.
However, Asean neutrality cannot mean inactivity. On the contrary, the current Asean chair - Brunei - must work with others in the group to rebuild trust, with the aim of beginning negotiations on a code of conduct for activities in the contested areas.
Last year's July 12 statement on Asean's six-point principles on the South China Sea bears reiteration. It will be critical that China is a part of this negotiation - as much as the Philippines and other claimants - and not feel that the 10 smaller countries are ganging up.
The legal process will move ahead - quickly and quite inexorably. It must also be expected that China will use economic and other levers to express its displeasure with Manila. The Philippines is testing China's intentions in law but its own endurance will be tested in economic and political spheres.
Challenging China under the UN convention is a decision by the Aquino administration that international law allows and no other country can stop. But what others in the region can and must do is help prevent the legal process from creating a political mess.
Simon Tay is chairman of the Singapore Institute of International Affairs and associate professor in the Faculty of Law at the National University of Singapore. He is also senior consultant at WongPartnership, a leading law firm in Singapore with regional practices