Introduction and context
The International Court of Justice (ICJ) ruling of December 16, 2015, resolved one of the most significant disputes in the recent diplomatic history between Costa Rica and Nicaragua: the dispute over sovereignty over Isla Portillos—also known as Isla Calero in the Costa Rican imagination—and the environmental damage caused in Costa Rican territory by Nicaraguan works in the so-called artificial canal.
This ruling became a milestone for international law in the region, but its true relevance cannot be understood without reviewing the long historical path that leads from the Transit Campaign (1856–1857) to modern treaties, awards, and disputes. The ICJ does not judge the military past, but it does apply the criteria, delimitations, and precedents that were born—or should have been born—from those events.
Costa Rica came to this litigation with an incomplete historical baggage:
a narrative void inherited from the silencing of the Transit Campaign and the figure of Major Máximo Blanco Rodríguez. This void, repeated in education, diplomacy, and politics, left out an essential component: the demonstration of effective control, historical use of the territory, and logistical dominance of the San Juan during 1856–1857.
That silence had consequences.
Why this document is key to the trilogy Las Aguas del Olvido
In the trilogy—Las Aguas Amargas del San Juan, Aguas Silenciadas, and La Frontera del Agua—this case occupies a central place because it represents:
1. The legal culmination of a century and a half of disputes.
The 2015 ruling is the final point of a chain that includes:
- the Cañas–Jerez Treaty (1858),
- the Cleveland Award (1888),
- the Alexander Agreement (1897),
- the Jerez–Molina Treaty (1896),
- and a succession of interpretations, misunderstandings, diplomatic errors, and omissions.
2. The mirror where the fragility of the national narrative is observed.
Costa Rica defended a territory with legal solvency, but without the symbolic force of its complete history. The military memory of 1856–1857—including the effective presence in Sarapiquí, San Carlos, and the banks of the San Juan—was never integrated into its modern diplomacy.
The ruling recognizes Costa Rican sovereignty but also exhibits how the country arrived at the court without a consolidated historical narrative that reinforced its arguments.
3. The bridge to the third book of the trilogy.
La Frontera del Agua will analyze how Costa Rica, despite military and legal triumphs, has lost strategic opportunities by not sustaining a narrative continuity between history, law, and geopolitics.
The Isla Portillos case demonstrates that the future of the San Juan River depends not only on treaties but on reconstructing the erased memory and entering the 21st century with a clear vision:
whoever controls the story controls the river.
Document content
The document includes:
- The arguments presented by Costa Rica and Nicaragua.
- The final delimitation established by the ICJ.
- The recognition of the environmental damage caused by Nicaragua and the corresponding reparation.
- The analysis of the sovereignty of Isla Portillos.
- The contemporary interpretation of the Cañas–Jerez Treaty more than 150 years after its signing.
Relevance for researchers, readers, and students
This ruling is indispensable for:
- understanding the current state of the border,
- linking modern international law with 19th-century military history,
- observing how a country negotiates territory when it has lost part of its historical memory,
- and assessing the importance of the San Juan in contemporary geopolitics.
The document is presented here as part of a living archive that will accompany the evolution of the trilogy.
Download document
👉 [Access the PDF of the International Court of Justice Ruling – 2015]
(link or button to insert when the file is available)
