Argentina’s Border Demarcation: Treaties and Arbitrations
Argentina’s International Borders: Key Agreements and Disputes
Uruguay Border Agreements
Río Uruguay (1961)
The boundary along the Río Uruguay was defined in 1961. From the Brazilian island to the Salto Grande Dam, the midline of the river is followed. From the reservoir to Punta Gorda, the deepest channel, known as the Vanguardia, is used. A reservation was made stating that Filomena, Juanico, and Mayor Islands are Uruguayan territory.
Río de la Plata (1973)
The 1973 agreement for the Río de la Plata established several key points:
- Established the limit of the riverbed and subsoil.
- Defined the outer limit of the river by a line stretching from the northern tip of Cape San Antonio (Argentina) to Punta del Este (Uruguay).
- Set lateral maritime limits extending up to 200 miles into the sea.
- Stipulated that Isla Martín García (Argentine jurisdiction) is administered by a mixed commission.
- Each country reserves the exclusive use of waters from its shore to 2 miles at sea, extending to 7 miles at the river’s mouth.
Brazil Border Agreements
Ríos Uruguay and Iguazú: The Misiones Question (1941)
This dispute, known as the “Misiones Question,” was resolved in 1895 through arbitration by the U.S. President (Cleveland). The boundary was determined to pass through the San Antonio and Pepirí Guazú rivers. The problem stemmed from a toponymic issue, as Brazil maintained these rivers were located to the west, while Argentina claimed they were to the east. The umpire ruled in favor of Brazil.
Bolivia Border Agreements
Argentina-Bolivia (1889)
In 1889, Argentina ceded the province of Tarija and the territory corresponding to the “Juntas de San Antonio” to Bolivia. This was in exchange for Bolivia’s rights over a section of the Atacama highlands. A special arrangement was necessary regarding the town of Yacuiba, which, being located south of latitude 22º South, should have belonged to Argentine territory.
Paraguay Border Agreements
The Chaco Boreal Question: Verde, Paraguay, and Pilcomayo Rivers (1878)
The “Chaco Boreal Question” was subject to arbitration by the U.S. President (Hayes) in 1878. Regarding the Pilcomayo River, the difficulty lay in the absence of a defined channel due to its continuous displacement. A conventional river course was agreed upon. In 1945, a photographic mosaic from Fortín Soledad to Salto Palmar was used to aid demarcation.
Chile Border Agreements
Puna Sector (1899)
In 1899, mediator Buchanan resolved the Puna Sector dispute. Two-thirds of the disputed territory was awarded to Argentina, based on a geometric limit from Cerro Zapaleri, Socompa, and Cerro Colorado to Paso de San Francisco.
Paso de San Francisco
A mistake in placing the third boundary marker in the wrong location led to arbitration by King Edward VII in 1902.
Arid Andes (1881)
The 1881 treaty presented two theses: Argentina’s proposed line of high peaks versus Chile’s watershed line. There is a line of coincidence from the Paso de San Francisco to the Pirehueico River (Neuquén).
Patagonian Andes
In the Patagonian Andes, the boundary line does not always match the high peaks or the watershed. Erroneous mapping led to the 1902 arbitration by King Edward VII, which established a mixed limit, partly following high peaks and partly the watershed. Later, other problems arose, which were resolved by Elizabeth II, including disputes over Lago del Desierto, the Palena River Basin, and the Palena River.
Beagle Channel
The Beagle Channel dispute initially involved Chilean claims over Picton, Nueva, and Lennox Islands. For its resolution, an English arbitration was held in 1977, which Argentina declared invalid in 1978. Mediation by Pope John Paul II began in 1980, and the conflict was finally resolved in 1984.
Continental Ice Field
The limit in the Continental Ice Field ranges between Mount Fitz Roy and Cerro Daudet. The boundary was agreed upon in the late nineteenth century and authenticated by the 1902 English award, but it had not been fully demarcated.
Lago del Desierto
The Lago del Desierto dispute was submitted to arbitration by a panel of American judges, who rendered their ruling in 1994, entirely in favor of Argentina.