The Laguna del Desierto incident occurred between four Chilean Carabineros and between 40 and 90 members of the Argentine National Gendarmerie and took place in an area south of O'Higgins/San Martín Lake on 6 November 1965, resulting in one lieutenant killed and a sergeant injured, both members of Carabineros, creating a tense atmosphere between Chile and Argentina.
Historical background
The British award of 1902 considered the demands of Chile and Argentina as irreconcilable and previous authorization of both governments draw a boundary between the extreme pretensions of the litigants. In the Laguna del Desierto region, the tribunal set the hito 62 (cornerstone 62) at the O'Higgins/San Martin Lake and draw the boundary from there to mount Fitz Roy on the Martínez de Rozas Range awarding Chile the complete valley of Laguna del Desierto.
In 1946 an aerial reconnaissance of the United States Air Force, ordered by the Chilean government, revealed that the lake emptied to the Atlantic shores. Chile and Argentina had to redraw their maps.
Argentine internal situation
The initially organized labour support for 1963 elected Argentine President Arturo Illia turned to antagonism during 1964, as secret plans for Juan Domingo Perón's return from exile took shape. Accordingly, the General Confederation of Labor (CGT) leader José Alonso called a general strike in May, and became a vocal opponent of the president. This antagonism intensified after Perón's failed attempt to return in December, and during 1965, CGT leaders began publicly hinting at support for a coup.
The triumph of the Peronists party in the March 1965 elections shook the Argentine Armed Forces, both among internal military factions linked to the Peronist movement, and in particular among the large section of the army which remained strongly anti-Peronist. In addition, a campaign against the government was also being carried out by important parts of the media, notably Primera Plana and Confirmado, the nation's leading newsmagazines. Seizing on minimally relevant events such as the President's refusal to support Operation Power Pack (Lyndon Johnson's April 1965 invasion of the Dominican Republic), Illia was nicknamed "the turtle" in both editorials and caricatures, and his rule was vaguely referred to as "slow," "dim-witted" and "lacking energy and decision," encouraging the military to take power and weakening the government even more; Confirmado went further, publicly exhorting the public to support a coup and publishing a (non-scientific) opinion poll touting public support for the illegal measure.
The incident
On 4 October 1965, the Chilean settler Domingo Sepúlveda was instructed by Argentine gendarmes to regularize his settlement by the Argentine authorities in Río Gallegos. On 9 October Sepúlveda went to the Chilean Police station at the O'Higgins/San Martín Lake to denounce the Argentine requirement. On 17 October Carabineros sent a platoon to the zone and built an outpost in the property of Juana Sepúlveda and later a six-man reconnaissance patrol was sent to a shelter 8 km farther south. They were major Miguel Torres Fernández, lieutenant Hernán Merino Correa, sergeant Miguel Manríquez, the lance-corporal Víctor Meza Durán and the Carabineros Julio Soto Jiménez and José Villagrán Garrido.
On 30 October, Eduardo Frei Montalva and Arturo Illia, presidents of Chile and Argentina, met in Mendoza, Argentina and agreed to revert to the status quo before the Argentine requirement: withdraw the forces, no further buildings for Carabineros or Gendarmerie in the zone.
On the Argentine side, on 1 November the operation Laguna del Desierto under the command of Osiris Villegas and Julio Rodolfo Alsogaray, chief of the V Division of the Argentine Army and Director of the Argentine Gendarmerie respectively, brought in several DC-3 flights the Gendarmerie Squadron "Buenos Aires" from El Palomar Airport to the zone and later, on 3 November, the Gendarmerie Squadron 43 was ordered from Río Turbio to meet the "Buenos Aires" in the same area. They were accompanied by journalists and photographers of the magazine Gente y la Actualidad.
On 6 November at 14:00 Major Torres received the order to return to the police station. Two Carabineros, Soto and Villagrán, were ordered to bring the horses and the other four men prepared their return. At 16:40 they were surrounded by approximately 90 Argentine Gendarmes. As the Chileans noted the encirclement, they called to negotiate, Argentine forces shot dead Lieutenant Hernán Merino and injured Sergeant Miguel Manríquez.