(Distances from the two deployment locations of HY-981. Created by Phan Van Song using Google Earth.)

After two and a half months of confrontation with Vietnam, on 15/7/2014 China withdrew the billion-dollar oil rig HY-981 that it had deployed near the Paracel Islands, the subject of a territorial dispute between the two countries since the early 20th century. The withdrawal of the oil rig has lowered tensions in the South China Sea, which had risen to the highest levels since China’s seizure of Johnson South Reef in the Spratly Islands in 1988, in which over 70 Vietnamese personels were killed.

The simmering territorial and maritime disputes in the region mean that similar incidents are likely to occur again. It is therefore worth trying to see what international law has to say about the rights and wrongs in this incident. It will be seen that a clear cut answer can be found, even if some underlying questions remain unresolved.

Sovereignty over the Paracels

The most obvious question is“Does sovereignty over the Paracels belong to China or Vietnam?”, even if, as will be shown later, this question does not determine who was right or wrong in the confrontation.

This question is in fact more difficult to answer than partisans on both sides would like to believe. China’s arguments which allude to distant history such as the Northern Song Dynasty might sound impressive to the layman, but they are unlikely to satisfy the requirement of international law that the acquisition of sovereignty over a territory is based on declarations and acts of sovereignty by the state, not by individuals. Vietnam’s arguments based on the activities of the Nguyen Dynasty and French assertions of sovereignty are, on the other hand, much more likely to satisfy this requirement.

However, Vietnam’s sovereignty claim may be affected by a note that North Vietnam’s Prime Minister Pham Van Dong sent to Chinese Premier Zhou Enlai in 1958, in which he recognised China’s Declaration of the Territorial Sea of the same year. In that declaration, China claimed a 12-nautical mile territorial for its territories, which it said to include the Paracel Islands and Spratly Islands. Vietnam’s counter argument seems to be based on the view that during the Vietnam War sovereignty over the Paracels and Spratlys was being maintained by South Vietnam, and that North Vietnam’s 1958 note which Pham sent to Zhou only addressed China’s claim to a territorial sea of 12 nautical miles, not the question of sovereignty to these islands. In any case, this is a topic that requires further research, and only an international court or tribunal’s answer to the question “Does sovereignty over the Paracels belong to China or Vietnam?” could be guaranteed to be objective and authoritative.

In whose waters?

The second question is “Was HY-981 deployed in waters belonging to Vietnam or China?” Naively one might think that the answer to this question depends on that to the first question. However, that is only true if HY-981 deployed in waters belonging the Paracels, and closer examination shows that this is unlikely to be the case.

The two deployment locations of the oil rig, between the Paracels and the Vietnamese coast and closer to that coast than to Hainan Island, means that if the Paracels belonged to Vietnam then the waters in the area would belong to Vietnam.If, on the other hand, the Paracels belonged to China then those waters would belong to China only if the Paracels were allocated an exclusive economic zone (EEZ) that extends to or beyond HY-981’s deployment locations. However, according to rulings by the international courts (such as the ICJ’s ruling in the Colombia-Nicaragua dispute) and international practice in maritime delimitations (such as China and Vietnam’s delimitation agreement in the Gulf of Tonkin), small islands such as Woody Island and Pattle Island in the Paracels are unlikely to be allocated an EEZ that extends more than a quarter of the distance to continental coasts. China's drilling location is 153 nautical miles from Vietnam's mainland, 190 nautical miles from China’s Hainan Island, 88 nautical miles from Woody Island and 58 nautical miles from Pattle Island. It is therefore most unlikely that if a court or tribunal is ask to rule on the matter it will agree that the Paracels’ EEZ can extend far enough to cover HY-981’s deployment location.

Thus, regardless of who owns the Paracels, the answer to the question “Do the waters around the oil rig belong to Vietnam or China?” is most likely to be Vietnam.

Obviously China does not accept this answer, as demonstrated by its actions. Unfortunately, given that it has rejected to the maximum possible extent the dispute settlement procedures specified in the United Nations Convention on the Law of the Sea (UNCLOS), no court or tribunal has the jurisdiction to uphold what is most likely to be right, and so the issue remains undetermined.

Given this regrettable state of affairs, which is brought about by China’s avoidance of international law of maritime delimitation, the third question is “Which country was legally right in this confrontation?” The answer to this question can be found in UNCLOS, which both Vietnam and China have ratified.

UNCLOS rules on disputes

Since there is no agreement between Vietnam and China on the question “Do the waters around the oil rig belong to Vietnam or China?” and both side have potentially valid answer from the legal point of view (even if, as shown earlier, Vietnam's case is much stronger), the waters around the oil rig is by definition disputed. This is where UNCLOS comes in.

Article 74(3) of the Convention stipulates that where there are unresolved conflicting EEZ claims,“the States concerned, in a spirit of understanding and cooperation, shall make every effort to enter into provisional arrangements of a practical nature and, during this transitional period, not to jeopardize or hamper the reaching of the final agreement. Such arrangements shall be without prejudice to the final delimitation.” In the 2007 judgement on the Guyana-Suriname dispute, the Permanent Court of Arbitration ruled that unilateral drilling in a disputed area is a violation of this Article. It is thus clear and undeniable that China’s deployment of a giant drilling rig is a violation of this Article, and Vietnam was legally correct in opposing this act.

Unfortunately, China’s rejection of UNCLOS’s dispute settlement procedures to the maximum possible extent again means that no court or tribunal has the jurisdiction to uphold what is certainly right. However, if Vietnam unilaterally pursued these procedures, there is a possibility that an UNCLOS Annex VII tribunal will find that China’s refusal to negotiate the waters around the Paracels with Vietnam is a violation of Article 279, which requires the two countries to “settle any dispute between them concerning the interpretation or application of this Convention by peaceful means in accordance with Article 2, paragraph 3, of the Charter of the United Nations”.


In any case, the answers to the three legal questions raised about the most recent bout of confrontation between Vietnam and China are as follows.

1. “Does sovereignty over the Paracels belong to China or Vietnam?”: Inconclusive, but this question is not a determinant for the confrontation over the deployment of HY-981.

2.“Was HY-981 deployed in waters belonging to Vietnam or China?”: According to jurisprudence and international practice in delimitation, the answer is most likely to be Vietnam, regardless of the answer to the first question.

3. “Is Vietnam or China legally right in this confrontation?”: According to UNCLOS as has been interpreted by the Permanent Court of Arbitration, the answer is definitely Vietnam, regardless of the answers to the first two questions.

By Duong Danh Huy