A Case for Rejecting Characterisation Approach for Mixed Disputes

International dispute settlement mechanisms are based on States’ consent. They can only adjudicate on those disputes that parties refer to them, and they have limited subject matter jurisdiction. For instance, the International Tribunal for the Law of the Sea (“ITLOS”) can only adjudicate on matters related to the United Nations Convention for the Law of the Sea (“UNCLOS”), and the World Trade Organisation’s dispute settlement bodies’ ratione materiae is limited to the General Agreement on Tariffs and Trade, and covered agreements. 

However, in reality, inter-states disputes often raise complex issues related to multiple fields of international law, and these disputes (mixed disputes) cannot fit neatly into one treaty or another. For instance, many issues related to the UNCLOS will necessarily raise issues regarding territorial disputes, because of the “land dominates the sea doctrine.” Thus, creating the need to bifurcate between inside and outside issues, whereby the inside issue can be decided by a tribunal as opposed to an outside issue which falls beyond their jurisdiction.

Mixed dispute problems have arisen in a plethora of cases, and have been adjudicated upon by the ICJ, ITLOS, PCA, and Investor-State Arbitrations; yet, the literature on the issue remains limited.

This article attempts to answer how tribunals should entertain mixed disputes. The PCA has addressed this issue recently by employing various approaches which have been broadly termed as the “characterisation approach,” that has been endorsed by commentators (see here, here, and here). This article first critically analyses PCA’s characterisation approach, and then it postulates why this approach should be displaced in favor of the “normative approach” which offers a more principled, internally consistent, and doctrinally supported alternative.

True Object Test

In Mauritius v. the UK, while deciding that Mauritius’ claim was not one characterised as concerning interpretation or application of the UNCLOS, the PCA took into account its true object, which, it determined, was not to bring a claim regarding the UNCLOS (the inside issue), but rather, to bring the sovereignty dispute (the outside issue) under the Tribunal’s jurisdiction (¶¶ 220, 207-09). This approach was reaffirmed in Philippines v. China, where the PCA rejected the claim that the Philippines’ submissions were primarily concerned with sovereignty as it found that the true claim of the Philippines was to forward a claim regarding the interpretation of the UNCLOS, and not its position in the surrounding territorial sovereignty dispute. 

The true object test, as has been exercised by the PCA in the above cases, brings subjectivity to a court’s analysis, as it requires the adjudicator (who may not be well equipped to examine complex international relations disputes) to take into account non-legal factors – such as political and historical context – to determine the true object of the claim.

It also overlooks the fact that one single legal injury may lead to multiple violations of a state’s obligations and, hence, more than one cause of action. In doing so, it establishes an approach where the lawfulness of a state’s action can only be evaluated against the obligation on which the claimant’s true object is perceived to rest. 

Relative Weight Test

The relative weight test requires the tribunal to determine “where the relative weight of the dispute” lays on the application and interpretation of a treaty it has jurisdiction (ratione materiae) over or an issue outside the court’s subject matter jurisdiction. The tribunal would only exercise jurisdiction if the issue outside its jurisdiction ratione materiae was ‘ancillary’ to the dispute.

There are two grounds on which the relative weight test can be criticised for its inconsistent and unsatisfactory application, and its demerits when compared with the normative approach.

In Mauritius v. the UK, the PCA concluded that the relative weight of Mauritius’ claim concerned the territorial dispute over Chagos, with the UK’s actions as a “coastal state” being ancillary to the dispute. The PCA reached this conclusion as there was “an extensive record, extending across a range of fora and instruments, documenting the Parties’ dispute over sovereignty,” (¶¶ 211-12). 

The application of the relative weight test in Mauritius v. the UK is unsatisfactory, as the majority in the PCA does not weigh the inside and outside issues in relation to one another, but merely notes the fact that the parties have had a long-standing territorial dispute. This fact only goes towards demonstrating that Mauritius’ true objective was for the Court to decide the territorial dispute between the parties. Thus, the PCA in Mauritius v. the UK conflates the true object and the relative weight tests.

On the other hand, the PCA, in Ukraine v. Russia, concluded that the relative weight was upon the territorial dispute between the two parties, as a determination of Ukraine’s allegations against Russia (the inside issue) would have required prior determination over the territorial dispute (the outside issue) (¶¶ 195-96).

While this approach deserves more merit, the Tribunal still does not weigh the inside and outside issues in conjunction with each other. Hence, it does not demonstrate that the external issue (territorial dispute) is more prominent than the internal issue, i.e., the interpretation and application of the UNCLOS. Moreover, this approach is contradictory to the observation made in Mauritius v. the UK, where the PCA noted that it did not rule out the possibility of prior determination over the issue of territorial sovereignty, which is ancillary to a dispute concerning the interpretation or application of the UNCLOS (¶ 221). The PCA’s inconsistency in applying this test is amplified by the fact that it did not apply the relative weight test in the Philippines v. China.

Instead, like in Ukraine v. Russia, it observed that the Philippines’ claim would relate to sovereignty if it required “prior determination” over it (¶ 153). Therefore, it used the fact that the dispute required prior determination on an outside issue to characterise the issue without carrying out the relative weight test.

Given that Ukraine v. Russia was the latest of these three cases, it merely combines and conflates the approach in Mauritius v. the UK (relative weight) and the Philippines v. China (prior determination). Therefore, the relative weight test has been inconsistent both in terms of its employment and its application.

Apart from the inconsistent practice, the relative weight test can introduce subjectivity in a court’s adjudication of a matter as it requires the arbitrators to weigh the relative weight of the legal claims. As the test currently stands, there is no standard that would guide a judge to locate the relative weight of the dispute; it essentially requires the adjudicator to gauge the intention of a party, therefore, entailing greater subjectivity. 

Normative Approach 

We endorse the normative approach as it is more objective than both the true object test, and the relative weight test, and it has been supported by the practice of international tribunals. 

The normative approach only requires a tribunal to determine whether the act in question before the tribunal falls within its subject matter jurisdiction (within the treaty’s scope), and whether it poses a question about the true object of the state or the relative weight of the claim.

For instance, in the Oil Platforms case (1996), the US asserted that Iran’s actual object was to recast a use of force issue as one of a violation of the Treaty of Amity. The ICJ, rejecting the US’ claim, did not look into Iran’s true object, and only viewed “whether the violations of the Treaty of 1955 pleaded by Iran do or do not fall within the provisions of the Treaty and whether, as a consequence, the dispute is one which the Court has jurisdiction ‘ratione materiae to entertain” (¶¶ 16-18, 51).

Most recently, the ICJ, applying the normative approach in the ICAO Appeal, Qatar v. UAE, implicitly rejected the true object test. The Court dismissed Qatar’s argument that the International Civil Aviation Organisation (“ICAO”) Council lacked jurisdiction over the case, since the real issue in the dispute between the Parties involved matters extending beyond the scope of aviation conventions. Thus, it observed that the mere fact that this disagreement had arisen in a broader political and legal context did not deprive the ICAO Council of its right to approach the ICJ (¶¶ 46, 48).

If the true object test had been employed by the ICJ in the Oil Platforms and ICAO Appeal, Qatar v. UAE decisions it would have had to potentially refuse to adjudicate Iran’s and Qatar’s claims, even if they fell within the Court’s jurisdiction ratione materiae. This is because their true purpose would have been to recharacterise a dispute which arose in a broader political and legal context.

Given that both the true object test and the relative weight test, as noted above, introduce subjectivity to legal matters, the normative approach is more attractive as it offers a more concrete and objective basis for a tribunal to adjudicate upon, since the court must only interpret the treaty to determine if the act in question fall within its scope. Treaty interpretation is much closer to an international lawyer’s skill set than examining the political context surrounding a dispute and probing into a state’s intentions.

Applying Normative Approach to Mauritius v. UK

Additionally, following the normative approach, the PCA in Mauritius v. UK would have reached the same conclusion regarding Mauritius’ claim that the UK violated its rights as a coastal state by establishing a Marine Protected Area around Chagos (¶ 163).

Mauritius’ claim required the PCA to determine if Mauritius had sovereignty over Chagos (the outside issue), and only then could it decide whether the UK violated its rights as a Coastal State (the inside issue) (¶ 203). Given the fact that the outside issue upon which the inside issue was conditional did not fall within the provisions of the UNCLOS, Mauritius’ claim would not have been one of the application and interpretation of the UNCLOS. Consequently, when following the normative approach, the tribunal will still have to refuse to exercise jurisdiction over a claim if it requires prior determination over an issue outside its jurisdiction ratione materiae.

Practice of International Tribunals

The normative approach is consistent with the approach of international tribunals; it has been followed by the ICJ in various other recent cases, including Iran v. US (2018) (¶ 30), Certain Iranian Assets (2019) (¶ 36), and Immunities and Criminal Proceedings (2018) (¶ 46). It has also been used by other tribunals, such as the International Tribunal for the Law of the Sea, in M/V “Louisa (2013) (¶ 99) when determining whether a dispute is one concerning the interpretation or application of a treaty. It was even applied by the Permanent Court of International Justice as far back as 1924 in the Mavrommatis Palestine Concessions case (Greece v. the UK) (pg. 16).


The characterisation approach is a sui generis development in international law, the adoption of which sets a dangerous precedent. It has been subject to limited criticism (see here also) while departing from the decades of the established practice of following the normative approach. Owing to the fact that it lacks internal coherence and it can expand a tribunal’s jurisdiction beyond a state’s consent, it has the potential to further erode states’ faith in international dispute settlement mechanisms, and must, hence, be replaced by a more concrete approach.

Rudraksh Lakra is a third-year law student at O.P. Jindal Global University. He has been a finalist in the Philip C. Jessup International Moot Court Competition India National Rounds. He has a keen interest in international trade, criminal, human rights, and international humanitarian law. 

Adhiraj Vikram Singh is a third-year law student at O.P. Jindal Global University. He is currently the convenor of the Jindal Debate Society and has a keen interest in the fields of arbitration law, feminist legal theory, international human rights and criminal law.

Image: Mahima Balaji (modified from Reuters, ITLOS, and ADR Institute).

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s