A Commentary on the Land and Maritime Delimitation and Sovereignty over Islands (Gabon/Equatorial Guinea) (2025)

The two African states of Equatorial Guinea and Gabon were the focus of recent international attention. And there is a good reason for that. On 19 May 2025, the International Court of Justice (henceforth: ICJ) delivered the merits of its long-awaited ruling in the case of Land and Maritime Delimitation and Sovereignty over Islands (Gabon/Equatorial Guinea) concerning their land and maritime dispute as well as the issue of sovereignty over the islands of Mbanié/Mbane, Cocotiers/Cocoteros and Conga.

This post is organized into two main segments. First, it briefly sketches out the case and its history as well as the findings relating to land and maritime disputes and the sovereignty issue of the islands. Secondly, in discussing some of the separate and dissenting opinions, it shares some thoughts on the most problematic aspects of the judgment.

A Brief Historical Background of the Case

The roots of contention extend back to the colonial past and (post)colonial present. The issue has been on the agenda since at least August 1972, when Gabonese forces seized and occupied the island of Mbanié/Mbane, with the country alleging that this was merely done for security reasons (para. 27). Ever since, previous years saw both disagreements but also multiple efforts to settle the dispute including a United Nations unsuccessful mediation in 2003-2004. Prospects of oil and hydrocarbon exploitation reserves around these islands seem to have reinvigorated these differences between the two parties. After various unsuccessful attempts and with no end in sight for more than four decades, the situation took a new turn when the two parties agreed in Marrakesh on 15 November 2016 to take the matter to the ICJ through a Special Agreement.

Rather than requesting a delimitation of their land and maritime boundaries, the Court was just asked “to determine whether the legal titles, treaties and international conventions invoked by the Parties have the force of law in the relations between the Gabonese Republic and the Republic of Equatorial Guinea in so far as they concern the delimitation of their common maritime and land boundaries and sovereignty over the islands of Mbanié/Mbañe, Cococtiers/Cocoteros, and Conga” (Article 1 (1) of the Special Agreement). This was made clear by both parties throughout their submissions.

Maps: © International Court of Justice, 19 May 2025

The Ruling of the Court of 19^th of May 2025

What are “Legal Titles”?

The first area of disagreement concerned the term “legal titles” in Article 1 (1) of the Special Agreement. Adopting a more restrictive interpretation, Gabon argued that this should only be understood as “treaties and international conventions” (para. 32), whereas Equatorial Guinea perceived this term as including legal titles alongside treaties and international conventions (para. 33). For the Court, the general wording employed did not require a narrower interpretation than it usually has (para. 43).

When a “Convention” is not a “Convention”?

Even more divergence existed on whether the alleged 1974 “Bata Convention Demarcating the Land and Maritime Frontiers of Equatorial Guinea and Gabon” (henceforth: 1974 “Bata Convention”) was adopted and could be characterized as a legal title. Recognizing its potential implications for the dispute as a whole, the Court first addressed this question. Gabon argued in its memorial and rejoinder that a treaty was signed at the city of Bata and it solved the issue of land and maritime boundaries as well as the issue of the islands (para. 28 and 47; Rejoinder of Gabon paras. 2.13 and 2.20). Conversely, Equatorial Guinea held the opposite view (para. 4; Reply of Equatorial Guinea paras. 3.38 and 3.58). While noting that the document “could be characterized as a treaty” (para. 72), according to the Vienna Convention on the Law of Treaties (1969), the Court concluded that this was not the case. To reach this conclusion, it examined in detail the parties’s intentions (paras. 77-78), the circumstances under which it was drawn up (para. 79) as well as the subsequent conduct of the parties (para. 87-90). For this reason, the majority of the Court noted that the “Convention” was not a treaty and could not be considered a legal title for the Special Agreement. As such, the dispute between the two countries was regulated by the 1900 Paris Special Convention on the Delimitation of French and Spanish Possessions in West Africa on the Coasts of the Sahara and the Gulf of Guinea (henceforth: 1900 Convention) only. As per the existence or not of the 1974 “Bata Convention”, Judge Ad Hoc Pinto appointed by Gabon voted against this point, suggesting that the Court should have taken into account the evidence in the form of statements submitted by Gabon (para. 11).

On the Land and Maritime Boundaries

The Court then focused its analysis on the land boundaries consisting of the Utamboni River area and the Kie River area. Having concluded that the 1974 “Bata Convention” was not a treaty, it found that Gabon’s claim regarding the modification of the 1900 Convention lacked solid ground (para. 126). In both cases, the Court concluded after analyzing subsequent practice that the boundaries had not been modified by the 1901 Franco-Spanish Delimitation Commission (paras. 144 and 155). Consequently, the legal titles were inherited from the former colonial powers of Spain and France in 1968 and 1960, respectively, on the basis of the 1900 Convention (para. 157). However, the Court cautioned that a different approach may be taken based on the ground today and the interests of the local population (para. 157).

After examining the issue about the Islands of Mbanié/Mbane, Cocotiers/Cocoteros and Conga, as seen in the next section, it turned its attention to the maritime boundaries. Despite recognizing the potential relevance of the United Nations Convention on the Law of the Sea (1982) for a common maritime boundary since both states have ratified the Convention, the ICJ noted that it does not constitute a “legal title” within the ambit of the 1900 Convention (paras. 210-211).

On the Islands of Mbanié/Mbane, Cocotiers/Cocoteros and Conga

Finally, the analysis turned to the small islands of Mbanié/Mbane, Cocotiers/Cocoteros and Conga. Due to their proximity to Corisco Island, the Court accepted that the islands should be treated as “a single unit” and as a result they maintain the same legal title (par. 180). Since once again the 1974 “Bata Convention” was not applicable (para. 181), the ICJ went to explore the Spanish title over the islands. Following a historical analysis, it recognized Spain’s continuous and uncontested display of authority that was accepted both by France before and after 1900 but also by Gabon after its independence in 1960 (paras. 191, 194 and 196). Consequently, the legal title to the islands held by Spain was succeeded by Equatorial Guinea when it gained its  independence (para. 199).

Some Reflections Based on Some of the Separate Opinions and Dissenting Opinions

However, the Court’s decision was not unanimous. Out of the separate and dissenting opinions, some common themes emerge. Firstly, the recourse to colonial legal terminology. This was noted by Judge Yusuf, Tladi and Xue. Notably, Judge Yusuf in his Separate Opinion chastised the wording employed by the Court which ranges from the acquisition of territory (para. 5) to the maintenance of colonial boundaries through the notion of uti possitedis (para. 16). Notwithstanding the dispute concerns an inter-African dispute, pre-colonial Africa is largely invisible in the judgment (paras. 13 and 24). And this is not only a trap for European-North American trained international lawyers and academics but also for African states as well (para. 20). Almost not a single word is lent by either the parties or the Court on this point. Regrettably, that was not the first case to raise such remarks (Frontier Dispute (Burkina Faso/Republic of Mali), 1986, Judge Ad-Hoc Abi-Saab, paras. 4, 5 and 11).

A related issue is that of sources employed. While the Special Agreement offered the parties the possibility to take into account both documentary and non-documentary evidence, Judge Xue underlines that only documentary evidence was considered in the final analysis (paras. 2 and 18). Both states in their submissions and replies submitted extensive volumes of documents, maps and translations to support their case. Nonetheless, other forms of sources except from “orthodox” historiographic ones – in this instance colonial archives – do not seem to have been raised nor taken into account. The parties and the Court, for example, remained silent on the existence of any African pre-colonial traditions.

A final issue was the role of the Court. Although the Court reiterated on multiple occasions its task, Judge Tladi argued that the latter had exceeded its remit by not only determining the applicable legal titles but going even further to delimit the actual boundaries at the expense of parties’ submissions (par. 17). This point was noted explicitly in the reasoning of Judge Ad Hoc Wolfrum appointed on behalf of Equatorial Guinea by recognizing that this occurred by the parties’ submissions as well (par. 11). In a perhaps tacit acknowledgment of exceeding its judicial contraints, the Court left open the door for the parties to reach a different arrangement based on the circumstances as they stand today and local population.

Concluding Remarks

To sum up, the present ruling marks the latest development for a dispute that has been going on for decades between these two African states and their efforts to settle their claims over their land and maritime boundaries and the three disputed islands. Decisions such as this one by the Court serve as a useful reminder that it can assist states by not only delimiting their land and maritime boundaries but also by bringing the parties together to the negotiating table and determining the applicable law for their future negotiations. Nonetheless, the manner in which the majority of the Court and the parties chose or not to address certain issues does raise some important questions about the language and methods employed and the role of the Court.

Regardless of whether one agrees with the majority and/or the minority, the omens for a diplomatic resolution to the dispute between Gabon and Equatorial Guinea seem rather positive at the moment. In the aftermath of the ruling, a spokesperson for the Gabonese presidency said that “Gabon and Equatorial Guinea have to live side-by-side, we can’t move away from each other. Therefore we will have to talk it over to solve all these problems”. Equatorial Guinea also seems to have responded positively. It remains to be seen whether this ruling will be a stepping stone for the parties to solve their differences once and for all or whether it will lead to further controversy in the near future. Previous experiences with neighboring countries such as São Tomé and Príncipe (1999 for Equatorial Guinea and 2001 for Gabon) may provide guidance for the way forward.