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South China Sea: Chinese Assertiveness and the Possibility of Further Legal Action; By Carlyle A. Th

C3S Article no: 0026/2017

We request your assessment about the possibility of Vietnam taking international legal action against China with respect to their territorial disputes in the South China Sea. 

Q1. Recently, we have seen Beijing’s growing assertiveness in the hotly contested waters of the South China Sea(including the promotion of 9-dash line, the potential establishment of an Air Defence Identification Zone, the building of artificial islands…).What do you think are the reasons behind these moves and their consequences? Is it a real threat to Vietnam as well as regional security and why?

ANSWER: China aims to exercise hegemony over the South China Sea by establishing a military presence and then exerting pressure on the United States to reduce if not end all military patrols in the South China Sea. China will not, however, interfere with commercial shipping or the transit of foreign naval vessels. China’s plan is long-term with a time frame of several decades.China will use its artificial islands to exert pressure on the littoral states to comply withChina’s wishes, this includes the Philippines, Malaysia, Brunei and Vietnam.China’s drive for hegemony is related to important strategic issues such as preventingU.S. warships from using the South China Sea in the event of a conflict with Taiwan.China wants to protect its southern military bases and protest, its southern flank. More importantly, China wants to create a safe haven for its nuclear ballistic submarines that operate from Hainan Island. And China wants to be able to track U.S. submarines the South China Sea using a network of helipads on its artificial islands. The helicopters will carry dipping sonar to detect submarine movements and act in cooperation with surface warships and aircraft.China’s actions are a long-term threat to regional security and China will pursue its objective just short of the use of armed force.

Q2. The Hague tribunal last year overwhelmingly backed the Philippines but laterPresident Duterte appeared to ignore it to seek closer ties with Beijing. Is the ruling useless already or did it have any affect?

ANSWER: The Award by the Arbitral Tribunal that heard the case brought by thePhilippines against China is in legal limbo. President Duterte has said he does not want to raise tensions with China by insisting that it be complied with immediately. ButPresident Duterte has also said that the Award should form the basis of any agreements reached with Beijing. Recent Chinese activities, such as placing close in weapon systems and surface to air missiles, have caused some misgivings by theSecretary of Defense in the Philippines. The key is whether China will agree to giveFilipino fishermen access to Scarborough Shoal. If China becomes more assertive it could provokes the Philippines to call for the implementation of the Award. The Award is now part of international case law. The major maritime powers, while they will not force China to implement it, will use the Award as the legal basis for their naval operations.

Q3. Should Vietnam bring the case to an international court like the Philippines did?Why and why not?

ANSWER: At the moment Vietnam has adopted the position of using international legal means as the last resort. There is no need at the moment for Vietnam to file a claim for an Arbitral Tribunal because the essential issues relating to the Spratly islands have already been decided. Vietnam should do so if China becomes assertive against any of the 21 features that Vietnam occupies. There is nothing to stop Vietnam from using the Arbitral Tribunal Award as the basis of its government-to-government discussions with China.If relations with China deteriorated with respect to the Spratly islands it is difficult to see what Vietnam’s legal action would be aimed at. With respect to Da Gac Ma, this was seized by China’s use of armed force. International law prohibits the acquisition of territory by force.If relations between China and Vietnam deteriorate Vietnam could consider a legal challenge to the Paracel islands. However, Vietnam cannot make a legal challenge to the question of sovereignty unless China agrees, and this is unlikely. Vietnam’s claim this circumstance would follow that of the Philippines and seek clarification of the status of features in the Paracels, are they islands, rocks or low tide elevations.The bottom line with respect to international legal action is that there are no powers of enforcement, especially if Vietnam invoked the compulsory dispute settlement mechanism and China refused to participate.At present, Vietnam should work within the framework between China and ASEANmembers to achieve a Code of Conduct in the South China Sea. Vietnam should insist that the COC be legally binding. At the same time, Vietnam must continue to build up its naval and air capacity for self-defence to deter China from acting aggressively.Suggested citation: Carlyle A. Thayer, “South China Sea: Chinese Assertiveness and thePossibility of Further Legal Action,”

[Carlyle A. Thayer is Emeritus Professor, The University of New South Wales at the Australian Defence Force Academy, Canberra. Email: All background briefs are posted on (search for Thayer). Thayer Consultancy provides political analysis of current regional security issues and other research support to selected clients.]

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