The decision of the Arbitral Tribunal (at the Permanent Court of Arbitration) in Chagos Marine Protected Area Arbitration (Mauritius v United Kingdom) has been eagerly awaited.  This is not only because of the critical substantive issues at stake, but also because of the significant jurisdictional matters that the Tribunal has had to address that may influence the operation of an important international dispute settlement regime into the future.

The arbitration was heard before an ad hoc arbitral tribunal constituted under the UN Convention on the Law of the Sea (UNCLOS), which issued its Award on 18 March 2015 (Award).  The President of the Tribunal was Professor Ivan Shearer AM and the other members were Sir Christopher Greenwood (appointed by the UK), Rudiger Wolfrum (appointed by Mauritius), Albert Hoffman and James Kateka.  Judges Wolfrum and Kateka appended a dissenting and concurring opinion to the Award (Dissenting and Concurring Opinion).

The substantive questions before the Tribunal concerned, among other things, the legality of the UK’s declaration of a marine protected area (MPA) off the Chagos Archipelago, which is located in the middle of the Indian Ocean.  Also at issue was the UK’s entitlement to declare such an area as the lawful ‘coastal state’ given that Mauritius has a reversionary title to sovereignty.

The jurisdictional issues related to the possible scope of the compulsory dispute settlement regime enshrined in UNCLOS.  The Tribunal considered whether (or when) questions relating to territorial sovereignty could fall within the jurisdiction of a court or tribunal constituted pursuant to the UNCLOS dispute settlement regime.  The approach of the Tribunal on these issues will have significance for a pending arbitration that the Philippines has instituted against China, also under the UNCLOS compulsory procedures.

In instituting proceedings against the UK under UNCLOS, Mauritius sought declaratory relief to the effect inter alia that the UK was not entitled to declare an MPA or maritime zones off the Chagos Archipelago because it was not the ‘coastal state’.  It was also argued that the MPA was incompatible with the substantive and procedural requirements under UNCLOS in relation to fishing rights held by Mauritius and regarding the protection and preservation of the marine environment (Award, [158]).

Jurisdiction to resolve territorial sovereignty disputes under article 288 of UNCLOS

The UK challenged the jurisdiction of the Tribunal, arguing that some of Mauritius’ claims did not fall within the terms of article 288 of UNCLOS.  Article 288 provides that a court or tribunal:

[s]hall have jurisdiction over any dispute concerning the interpretation or application of this Convention which is submitted to it in accordance with this Part.

The UK further argued that exceptions to jurisdiction under article 297, which include fisheries disputes in the Exclusive Economic Zone, also applied.

It is the arguments and discussion around the interpretation of article 288 that are of most interest in considering the implications for jurisdiction when there is a dispute that also concerns contested territorial sovereignty.  The UK submitted that the question of its sovereignty over Chagos was at the heart of the dispute and that it was illegitimate for Mauritius to represent that its claims related primarily to the interpretation or application of UNCLOS (Award, [169] – [174]).  Mauritius argued that a review of the drafting history of the dispute settlement regime indicated that UNCLOS negotiators had considered the question of contested sovereignty but had not reached consensus on an explicit exclusion (Award, [179]).  As such, it could not be concluded that questions of sovereignty were inherently beyond the jurisdiction of a tribunal operating under UNCLOS (Award, [178]).

Both states further considered the systemic implications of their respective positions.  The UK argued that there was a ‘grave danger’ for abuse in endorsing the position of Mauritius (Award, [198]), whereas Mauritius thought the dispute settlement regime would be strengthened.  For Mauritius, to decline jurisdiction would ‘exacerbate the dispute, to prolong it unnecessarily, and to signal that Part XV serves to perpetuate a colonial era dispute such as this one’ (Award, [201]).

To resolve this issue, the Tribunal considered that it must first determine whether the nature of the  Mauritian claim concerned territorial sovereignty, and if so, then decide to what extent it could resolve such a claim ‘as a necessary precondition to a determination of rights and duties in the adjacent sea’ (Award, [206]).  In responding to the first question, the Tribunal determined that the claims concerning the UK’s status as the ‘coastal state’ of the Chagos did indeed relate to land sovereignty over the Archipelago (Award, [207] – [212] and [229] – [230]).  In assessing whether it had jurisdiction to resolve this question, the Tribunal considered that the lack of attention in the drafting history would have more likely reflected the view that:

[n]one of the Conference participants expected that a long-standing dispute over territorial sovereignty would ever be considered to be a dispute “concerning the interpretation or application of the Convention”(Award, [215])

The Tribunal concluded that where the real issue in a case did not concern the interpretation or application of UNCLOS then a tribunal or court constituted under article 288 would have no jurisdiction over that claim (Award, [220]).

While the Tribunal did not have jurisdiction in respect of the questions pertaining to territorial sovereignty, it unanimously determined that it did have jurisdiction with respect to the Mauritian claim that the UK’s declaration of the MPA was incompatible with its obligations under UNCLOS.  In this respect it was held that the UK had breached its obligations under UNCLOS.

The jurisdictional questions in the decision could be significant for the Philippines v China arbitration.  In that case, the Philippines has asked an ad hoc arbitral tribunal constituted under UNCLOS to consider inter alia whether various features in the South China Sea are rocks, islands or low-tide elevations to determine their differing entitlements to maritime zones.  The ownership of these features is also disputed between the Philippines and China.  Unlike the Mauritius v UK case, however, the Philippines has explicitly stated that it is not asking the Tribunal to resolve questions of territorial sovereignty.  However, in a paper released from the Chinese Ministry of Foreign Affairs, China has argued that this case squarely concerns questions of contested territorial sovereignty and therefore falls outside the jurisdiction of the UNCLOS dispute settlement regime.  It should be noted that China has otherwise refused to participate in the arbitration and that this position paper is the only documentation from China responding to the Philippines’ claims.

The critical issue in Philippines v China, as with Mauritius v UK, is how the case is characterised.  Is it possible to make determinations about the maritime entitlements of certain islands, rocks or low-tide elevations without knowing which state owns those features?  I have argued elsewhere that it is, in my view, impossible to separate any consideration of entitlements from the question of who is so entitled.  What is the point of knowing that there are sovereign rights to fish within 200 miles of an island if it is not known which state has those sovereign rights?  The territorial sovereignty dispute is the real heart of the problem in Philippines v China.

Judges Kateka and Wolfrum dissented from the majority in Mauritius v UK in so far as it was held that there was no jurisdiction to resolve this territorial sovereignty claim within the UNCLOS regime.  They instead considered that the majority had read an additional, implicit limitation into the dispute settlement regime (Dissenting and Concurring Opinion, [37] – [45]).  This criticism does not strike me as warranted, however, because the Tribunal was instead answering the question of whether or not the dispute was one relating to the interpretation or application of UNCLOS.  The determination that a dispute does not concern the interpretation or application of UNCLOS is simply an application of article 288 rather than the creation of a new exception.

Yet while I personally support the finding of the majority on this point, it must be observed that Judge Wolfrum is the appointed judge of the Philippines in the Philippines v China arbitration and is apparently amenable to arguments that the UNCLOS dispute settlement regime can encompass territorial sovereignty disputes.  It will be interesting to see whether another ad hoc arbitral tribunal grapples with a similar, albeit not identical, issue.

Exchange of Views

A further important lesson from Mauritius v UK relates to the interpretation of article 283 of UNCLOS, which requires parties in dispute to ‘proceed expeditiously to an exchange of views regarding its settlement by negotiation or other peaceful means’.  The Tribunal emphasised that this obligation was one that:

[r]equires the Parties to exchange views regarding the means for resolving their dispute; it does not require the Parties to in fact engage in negotiations or other forms of peaceful dispute resolution.  As a matter of textual construction, the Tribunal considers that Article 283 cannot be understood as an obligation to negotiate the substance of the dispute (Award, [378])

As such, article 283 does not necessitate that a party specify any particular claim it makes under UNCLOS in the course of those exchanges, as the UK had argued.

China has raised an objection to jurisdiction based on article 283 in its position paper, taking a similar position to the UK that the Philippines had not sought to exchange views on the claims that were ultimately presented to the arbitral tribunal.  While this argument was already unconvincing – given undoubted attempts to resolve the outstanding issues between the parties – the Mauritius v UK decision has reinforced the Philippines’ position that its many efforts to resolve the dispute do reflect an exchange of views for the purposes of Article 283.

Concluding remarks

Although Judges Wolfrum and Kateka argued that the Tribunal was effectively changing the balance achieved at the Third UN Conference on the Law of the Sea in respect of dispute settlement (Dissenting and Concurring Opinion, [45]), arguably their views favouring a determination of contested territorial sovereignty would take the UNCLOS dispute settlement regime to a broader set of disputes than its drafters anticipated.  In holding that the UK had failed to give due regard to the rights of Mauritius in establishing the Chagos MPA, Mauritius v UK has shown that it is possible to make important contributions to the law of the sea and resolve complex questions that arise under UNCLOS.  The Philippines v China arbitration may well do the same if it assesses the legality of China’s so-called nine-dash line as a claim to maritime entitlement from mainland China.  But the ongoing viability and effectiveness of the UNCLOS dispute settlement regime will be best enhanced if jurisdictional decisions do not involve a reach into areas that do not properly concern the interpretation or application of that Convention.

Natalie Klein, Professor and Dean, Macquarie Law School; Vice-President of the ILA (Australian Branch).