The salient geographical details are that the rig, Haiyang 981, is deployed about 130 nautical miles from Vietnam’s undisputed continental coast and Ly Son Island, 180 nautical miles from China’s undisputed Hainan Island. It is 17 nautical miles from disputed Triton Island, which is a rock that does not qualify for an exclusive economic zone (EEZ) or any entitlement beyond 12 nautical miles, and 103 nautical miles from disputed Woody Island, which might be entitled to an EEZ of up to 200 nautical miles.

Since China has made a declaration under Article 298 of UNCLOS to be exempted from the convention’s compulsory dispute settlement procedure for several categories of disputes, including those relating to maritime delimitation, this procedure cannot be applied to determine whether Haiyang 981 is deployed within the EEZ generated by 1) Vietnam’s undisputed continental coast (which would mean the location of deployment belongs to Vietnam outright), 2) China’s Hainan Island (which would mean the location belongs to China outright), or 3) the disputed Paracels such as Woody Island (which would mean the location is contested).

While UNCLOS arbitrators would not have jurisdiction to choose among these three possibilities, they would likely recognize that a legal dispute exists. The presence of nearby coasts and the long-standing conflicting claims over the both the Paracels and the EEZ in this area are sufficient to constitute a legal dispute: the oil rig is located in an area of overlapping, potentially valid EEZ claims. This is true regardless of questions of sovereignty, allocation, or EEZ entitlements regarding the Paracels.

The recognition by the arbitrators that the oil rig is in a disputed area is inherently neutral and would not by itself disadvantage either side, but it would have important implications.

It is true that China’s declaration under Article 298 means that the arbitrators would not have the jurisdiction to interpret or apply Article 74, on the delimitation of and cooperation in disputed EEZs, to rule against it. However, its long-standing policy of unilateral actions and non-negotiation for the disputed EEZ could be ruled as a violation of Article 279, which stipulates that:

States Parties shall 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 and, to this end, shall seek a solution by the means indicated in Article 33, paragraph 1, of the Charter.

That would be an important legal victory for Vietnam. Up until now China has maintained that there are no disputes over the Paracels or the EEZ in this area, and thus it has no legal obligation to resolve anything with Vietnam, and can act unilaterally. If the arbitrators rule against this regarding the EEZ, it will create enormous legal and diplomatic pressure on China to refrain from unilateral actions and to come to the negotiation table. This is the only way to reduce and prevent future tensions between China and Vietnam in this area.

Vietnam might have reservations about taking this confrontation to court. First, it might be concerned about the backlash from China. Second, due to the expansiveness of China’s maritime claims, as symbolized by the nine-dashed line, Vietnam has traditionally been wary about accepting that these claims constitute a legal dispute.

Regarding the first reservation, seeking to resolve disputes using international law is better than engaging in a confrontation that involves using force.

Regarding the second reservation, in this particular case China has not tried to use the nine-dashed line as justification for the location of Haiyang 981. Furthermore, this location is close enough to China’s Hainan Island and the disputed Paracels that Vietnam would not be giving away much in accepting that a legal dispute exists there.

Overcoming these reservations and submitting the confrontation over the deployment of Haiyang 981 to UNCLOS’s compulsory dispute resolution mechanism will result in the arbitrators recognizing that China had deployed this oil rig in a disputed area. This will may open a way to defuse the current tensions as well as put a legal obligation and diplomatic pressure on China to come to the negotiation table, which will help to prevent future provocations. In addition, pending the legal process, Vietnam can seek interim measures to block Haiyang 981’s operations.

The author would like to thank Greg Poling for his comments in drafting the piece.

Dr. Huy Duong is an analyst on the disputes in the South China Sea Sea. This article was originally published on cogitASIA.