In the autumn of 2010, the commander of a Nicaraguan detachment carrying out earthworks in Caribbean swamplands cited Google Maps as proof that he was on his own country’s territory. The map was lying — but the dispute it had wandered into was a century and a half older than it was.
The border between Costa Rica and Nicaragua runs along the San Juan River — and that sounds simple until you look at the river up close. The San Juan flows out of Lake Nicaragua, Central America’s largest freshwater body, and eastward toward the Caribbean Sea, through lowland tropical forests and swamps. In its delta, the river breaks into branches, channels, and lagoons that change shape after every rainy season. The ground here is a mix of silt, peat, and standing water; solid land turns into swamp without warning. Calero Island — Costa Rica’s largest river island — is in fact a marshy lowland between channels, and the word “island” applies to it only in the sense cartographers use it: a piece of land surrounded by water. Walking across it is not for everyone. Drawing a border across it is for people who believe rivers stay put.
It was precisely in this delta, in the Isla Portillos area — a narrow strip of land between the San Juan River and Harbor Head Lagoon — that a crisis flared in 2010. But to understand why a swamp could trigger a diplomatic scandal, we have to return to a document signed a century and a half before satellites appeared.
On 15 April 1858, Costa Rica and Nicaragua signed the Cañas-Jerez Treaty, which defined the line of their shared border. The San Juan River was recognized as Nicaraguan — sovereignty over it belonged to Nicaragua. But Costa Rica received the right of free navigation on the river for commercial purposes: merchant vessels could travel up and down the San Juan without restriction. For a considerable stretch, the border ran along the river’s right-hand (Costa Rican) bank — meaning the waterway itself remained entirely on the Nicaraguan side, while Costa Rica owned the bank. The wording was typical of the 19th century: clear enough to sign, vague enough to argue over for decades.
The disputes began almost immediately. By 1888, the disagreements had become so sharp that both sides turned to an arbitrator — US President Grover Cleveland. His arbitral award upheld the validity of the 1858 treaty and clarified a number of provisions, including Costa Rica’s navigation rights. But the arbitration did not settle every question: the precise border line in the delta, where the river splits into branches, remained open to interpretation. Subsequent boundary commissions, working in the early 20th century, marked the border using specific landmarks — trees, bends in the river, channels — which over a hundred years had shifted, become overgrown, or disappeared altogether.
The result was a border legally fixed by treaty and arbitration, but physically tied to a landscape that does not stand still. Over a century and a half, the San Juan River changed course, channels silted up, new ones appeared. The question of exactly where the river’s right bank lay at a particular point in the delta could have different answers depending on which map you held in your hands and what year it had been made.
In October 2010, Nicaragua began dredging a stretch of the San Juan River near its mouth at the Caribbean Sea. The official goal was to restore navigability to a river whose channel had silted up. The operation was led by Eden Pastora — a colorful figure well known across Central America: a former Sandinista commander, guerrilla fighter, and later opposition figure who had returned to Daniel Ortega’s side by 2010. Pastora commanded a detachment that, alongside deepening the river channel, was cutting a canal through swampy ground in the Isla Portillos area.
Costa Rica declared that Nicaraguan soldiers and workers had entered its territory, cut down forest, and raised the Nicaraguan flag on Calero Island. The crisis moved quickly: Costa Rica, which has had no army since 1948, sent police units to the border and appealed to the Organization of American States. Nicaragua insisted that the work was being carried out on its own land.
And then an unexpected participant entered the diplomatic conflict. Eden Pastora, responding to accusations of invasion, publicly stated that he had checked the border on Google Maps — and the map showed that the disputed area belonged to Nicaragua. The border line on the screen had been shifted roughly 2.7 kilometers into Costa Rican territory. In a swampy delta, where distances are short and landmarks blurred, that is an enormous error — enough to “move” an entire piece of land from one country to another.
What still gets me is the scene itself: a military commander with a combat past standing in the middle of a tropical swamp and citing a commercial internet service as a source of territorial law. It would be funny if there had not been real excavators, felled trees, and a diplomatic scandal behind it.
Google reacted relatively quickly, and its response was, in essence, an admission of error. The company confirmed that Google Maps did indeed contain an inaccuracy in its depiction of the border between the two countries. The line had been drawn incorrectly, and the disputed area had been “assigned” to Nicaragua. At the same time, in another product from the same company — Google Earth — the border was drawn differently, closer to the actual legal situation. Two services from one developer showed different borders for the same states.
Google corrected the data in Maps and issued a statement whose essence came down to one simple thought: online maps are not, and cannot be, a basis for determining national borders or for the actions of armed forces.
How did the discrepancy between the two products arise at all? Mapping services do not draw borders from scratch. They obtain boundary layers from geodata suppliers — commercial companies and government agencies that collect, process, and license spatial information. At the time, Google Maps used data from one set of suppliers, while Google Earth used another. Each supplier could rely on different source maps, different editions, and different degrees of generalization — the process by which fine details are smoothed out for display at a given scale.
Generalization is something the ordinary user never thinks about, but for border areas it is critical. When you zoom out on a map, a winding river border is reduced to a few segments. The algorithm decides which bends to preserve and which to straighten. In open country, an error of several hundred meters may go unnoticed. In a delta, where channels run parallel to one another just a couple of kilometers apart, such “straightening” can shift a border from one channel to another — and move territory between states.
There is also the matter of updates. Borders in cartographic databases are not lines carved in stone, but entries in tables that are edited from time to time. An update may arrive late from a supplier, may be applied to one product before another, may contain inaccuracies of its own. The legal disclaimers — the fine print at the bottom of a map stating that the depiction of borders does not represent the company’s position on territorial disputes — exist for precisely such cases. But who reads the fine print when there is a beautiful, confident, colorful line on the screen?
On 18 November 2010 — less than a month after the crisis began — Costa Rica filed a case with the International Court of Justice in The Hague. The case was called “Certain Activities Carried Out by Nicaragua in the Border Area.” In parallel, Nicaragua filed a counterclaim, accusing Costa Rica of building a road along the border in violation of environmental standards. The Court joined both cases into a single proceeding.
The case lasted five years. The Court examined the 1858 treaty, the Cleveland arbitration, subsequent demarcation documents, satellite imagery, and expert opinions from hydrologists and cartographers. The question was specific: who owned the territory in the Isla Portillos area and the northern part of Calero Island, which Nicaraguan detachments had entered?
On 16 December 2015, the Court delivered its judgment. It confirmed Costa Rica’s sovereignty over the disputed territory. Nicaragua was found to have violated the territorial integrity of its neighboring state. The Court also ordered Nicaragua to pay compensation for environmental damage inflicted on the disputed area — the amount of compensation was determined in a subsequent ruling. On the counterclaim, the Court found that Costa Rica had also breached its obligations — by failing to conduct an environmental assessment when building the border road — but this was a matter of procedure, not the border.
Google Maps had corrected its map long before then. In none of the Court’s documents did the digital service appear as a significant circumstance of the case — logically enough: the Court relied on treaties, arbitrations, and satellite surveying, not browser screenshots.
After the events of 2010, the story made headlines around the world under the label “Google Maps sparked a war.” That is, of course, an exaggeration — and a fairly crude one. The conflict between Costa Rica and Nicaragua over the San Juan River had been smoldering for a century and a half. The dredging work had been planned long before anyone opened a browser. By citing the map, Eden Pastora was more likely looking for a convenient excuse than making strategic decisions based on a line of pixels.
But the situation itself laid bare the difference between a paper map and a digital one. A paper map in an atlas always bore traces of its origins: the publisher, the year of issue, the scale, the projection, sometimes an explicit marking of disputed territories through hatching or dashed lines. A digital map on a phone screen looks different. It is smooth, seamless, updated imperceptibly, gives no indication of the scale at which it was compiled, and does not remind you of its sources. It creates the impression of objectivity — a window through which reality can be seen. But it is not a window. It is a render — the product of algorithms, databases, commercial licenses, and editorial decisions, any one of which may contain an error.
It seems to me that the most valuable thing in this story is not the curiosity of a commander and a browser, but the fact that three different systems for describing territory — legal (the treaty), physical (the river and the swamp), and digital (the map on the screen) — came apart from one another, and each claimed to be true. The 1858 treaty tied the border to the bank of a river that has changed its course since then. The river knew nothing of the treaty. And the map knew nothing of either the river or the treaty — it knew only its supplier’s database.
The International Court of Justice’s ruling in 2015 settled the legal question. But the technological problem remained: hundreds of millions of people use mapping services every day, and for the overwhelming majority of them, the line on the screen is the border. Google, Apple, Yandex, and other companies are forced to decide how to depict disputed territories — from Crimea to Kashmir, from Western Sahara to the Golan Heights — and those decisions are inevitably political, even when companies insist on their neutrality. Every mapping service contains a legal disclaimer stating that its depiction of borders does not represent a position on territorial matters, but lawyers read the disclaimer, while everyone else reads the map.
In the swamps of the San Juan delta, it is quiet now. The excavators are gone, the flags have been taken down, all awarded compensation has been paid. The line on Google Maps runs where it is supposed to run under the Court’s decision. But somewhere in the world right now, another line on another map has been drawn with an error of a couple of kilometers — and someone may already be taking it for fact.