Beagle conflict The Beagle conflict was a border dispute between Chile and Argentina over the possession of Picton , Lennox and Nueva islands and the scope of the maritime jurisdiction associated with those islands that brought the countries to the brink of war in 1978 . The islands are strategically located off the south edge of Tierra del Fuego and at the east end of the Beagle Channel . The Beagle channel , the Straits of Magellan and the Drake Passage are the only three waterways between the Pacific Ocean and the Atlantic Ocean in the southern hemisphere . After refusing to abide by a binding international award giving the islands to Chile , the Argentine junta pushed the controversy to the brink of war in 1978 in order to produce a boundary consistent with Argentine claims . The Beagle conflict is seen as the main reason for Chilean support to the United Kingdom during the Falklands War of 1982 . The conflict began in 1904 with the first official Argentine claims over the islands that have always been under Chilean control . The conflict passed through several status : since 1881 Chilean islands , since 1904 disputed islands , direct negotiations , submitted to a binding international tribunal , direct negotiations again , brinkmanship . The conflict was resolved through papal mediation and since 1984 Argentina recognizes the islands as Chilean territory . The 1984 treaty resolves also several collateral issues of great importance , including navigation rights , sovereignty over other islands in the Fuegian Archipelago , delimitation of the Straits of Magellan , and maritime boundaries south to Cape Horn and beyond . Background . For a long time after its first exploration by Europeans , the region of Patagonia and the Tierra del Fuego archipelago remained free from colonial settlements because of its inhospitable climate , harsh conditions and sparse local vegetation . After the disaster of Puerto del Hambre ( 1584 ) during the regency of Philip II of Spain no other attempts of settlements were made in the zone . In 1843 the Chilean government sent an expedition with the appointed task of establishing a permanent settlement on the shores of the Strait of Magellan . The founding act of the settlement of Fuerte Bulnes took place on 21 September 1843 . A few years later ( 1848 ) the settlement moved to Punta Arenas . Argentine Ushuaia was founded by English born Thomas Bridges in 1869 . In 1881 , Chile and Argentina attempted to definitively resolve their territorial disputes through a comprehensive agreement known as the Boundary treaty of 1881 between Chile and Argentina . This agreement provided that the border between the two countries would follow : Until 1887 there was no doubt in Argentina and Chile that the islands Picton , Nueva and Lennox belonged to Chile : In 1904 the Argentine government solicited Chile to define jointly which was the deepest arm of the Beagle channel in the zone in order to find the demarcation of the border . On the basis of the international cartography of the zone , the descriptions of the discoverer of the channel , and the discourse of the signatories of the 1881 Treaty , Chile initially did not attach importance to the note . The chief of the Argentine exploring commission of the southern territories , Francisco P . Moreno in a memorandum to the British Ambassador in Buenos Aires , 1918 , saw the Argentine claim as baseless : The unresolved conflict continued to simmer . During the Snipe incident , Argentine forces destroyed a Chilean lighthouse on the Snipe islet at the entry of the Beagle Channel installed on 1 May 1958 , put up their own and landed marines on the islet , provoking a dangerous build up . Later both countries agreed to pull back military forces and dismantle the lighthouses . Interests of the parties . Over the years the growing importance of the Antarctic , the navigation route s between the Pacific Ocean and the Atlantic Ocean , the expectance of oil fields in the zone , fishing right s led both countries to become hardened in their positions and the conflict was extended to other issues regarding the zone . There was a controversy about the east end of the Straits of Magellan . Both countries agreed about the boundary line , but not about the end of the Straits . The Chilean view was that the Straits ended at the boundary line and eastward continued the Atlantic Ocean and therefore Chile had a " beach " at ( and its projection over ) the Atlantic Ocean and it enjoyed sole control of the Straits themselves . The Argentine view was that the Straits continued eastward of the border and that the east end of the Straits of Magallan belonged to Argentina . Under this view , it was coproprietor with the right to co - regulate the navigation through the Straits and Chile had no border with the Atlantic Ocean . The west end of the Straits of Magellan was also a cause of conflict . Argentina considered the channel s and bay s part of the straits and demanded free navigation through all waters as stipulated in the Boundary Treaty of 1881 for the Straits . On 14 June 1977 , the Chilean Government issued the decree n°416 over the baselines ( See Chilean Baselines Map ) . The decree had two main implications for the controversy . First , it extended the range from which Chile might attempt to project its 12 - miles territorial sea and 200 - mile Exclusive Economic Zone along a continued line from Picton , Nueva , and Lennox Islands as far south as Cape Horn , thus greatly increasing its potential maritime jurisdiction to the east and southeast . Second , it effectively converted all waters enclosed by the baselines into Chilean internal waters where navigational rights for Argentina would exist only through explicit agreements with Chile . The Argentine port of Ushuaia , located on the north shore of the east Beagle Channel , had no direct free way to the Pacific Ocean through Argentine waters . Argentina has so far considered its unfettered use of the waters surrounding the Fuegian Archipelago to be a matter of critical importance for its commercial and military navigation . The two countries have always linked their Antarctic claims to their continental possessions because the nearness and the projection of the countries over the Antarctic can substantiate a claim over territories . History of the conflict . Attempts to clear up the dispute were unsuccessful from 1904 until 1971 . Incidents . The increasing significance of the region led to various incidents and confrontations between Chile and Argentina around transit and fishing rights , which potentially could lead to full scale war . The Snipe incident was the most serious incident occurred in the zone . Beagle Channel Arbitration 1971 - 1977 . In 1971 Chile and Argentina signed an agreement formally submitting the Beagle Channel issue to binding arbitration under auspices of the UK ' s Queen Elizabeth II . The court that was to decide the controversy was composed of five judges selected by Chile and Argentina from the International Court of Justice at The Hague . The court of arbitration ' s final decision would be submitted to the British Crown , which was then to recommend acceptance or rejection of the award of the court but not to modify it . On 2 May 1977 the court ruled that the islands and all adjacent formations belonged to Chile . See the Report and decision of the Court of Arbitration . On 25 January 1978 Argentina rejected the ruling , and attempted via military force to challenge the Chilean commitment to defend the territory , and to coerce Chile into negotiating a division of the islands that would produce a boundary consistent with Argentine claims . Direct negotiations 1977 - 1978 . Direct negotiations between Chile and Argentina began after the announcement of the binding arbitration ruling , on 2 May 1977 , and ended with the Act of Montevideo , Uruguay , on 9 January 1979 , where both countries accepted papal mediation after Argentina aborted Operation Soberanía . In the interim , both countries deployed military forces , moving to the brink of open warfare in tandem with a frenzy of diplomatic activity . This was the most dangerous phase of the Beagle conflict ; open warfare seemed a real possibility Operation Soberanía 1978 . On 22 December 1978 Argentina initiated Operation Soberanía , an attempt via military force to occupy the islands around Cape Horn , intending to judge from Chile ' s response whether to advance further . However , the operation was aborted within a few hours . Instead of renewing the operation at the next window of opportunity , the junta in Buenos Aires decided to allow the Pope to mediate the dispute through the offices of Cardinal Antonio Samoré , his special envoy . Papal mediation 1979 - 1984 . On 9 January 1979 , the Act of Montevideo was signed pledging both sides to a peaceful solution and a return to the military situation of early 1977 . The Pope proposed 1980 a solution that was accepted by Chile and rejected by Argentina . The detention of alleged spies on both sides of the border , the following border closing by Argentina on 28 April 1981 , and the Argentine repudiation of the " General Treaty on the Judicial Settlement of Disputes " in January 1982 maintained the danger of war . Six weeks before the Falklands War , Argentina provoked the ARA " Gurruchaga " incident with Chile at Deceit Island . The Falklands War 1982 . The Anglo - Chilean relations had been deteriorating since the Sheila Cassidy Affair in 1973 . In 1982 , Argentina went to war against the United Kingdom in the Falklands War . The Argentine plan included the military occupation of the disputed islands at the Beagle channel after the invasion of the Falklands , as stated by Brigadier Basilio Lami Dozo , chief of the Argentine Air Force during the Falklands war , in an interview with the Argentine magazine Perfil : In 1982 , Argentina still secretly considered Chile an enemy . Chile , perhaps suspecting an Argentine invasion , argued that it was not bound to support Argentina against the UK under the Inter - American Treaty of Reciprocal Assistance because that treaty was defensive in nature , while Argentina was the aggressor in this case and both Chile and Argentina deployed their respective militaries to the border . The common challenge made the chance of military co - operation between the UK and Chile a distinct possibility and during the war Chile provided the UK with limited , but significant information . One of the reasons given for the absence of the Argentine Navy and higher numbers of professional soldiers during the Falklands War was that these forces had to be kept in reserve in case they were needed against Chile . Treaty of Peace and Friendship of 1984 between Chile and Argentina . Tensions between Argentina and Chile did not subside until the democratic government of Raúl Alfonsín took office in Argentina in December 1983 . Still isolated diplomatically due to the War , the Alfonsín administration made great efforts to stabilize the border situation . Without the support of the opposition , Alfonsín called for non - binding referendum on 25 November 1984 , which produced a result of 82 . 6 % in favour of the second papal proposal . The voting was close only in the territory of Tierra del Fuego , which included the Argentine sector of the disputed Beagle Channel and many military personnel . The vote there was narrowly in favor of the treaty . On 29 November 1984 Argentina and Chile signed a protocol of agreement to a treaty at Vatican City giving the islands to Chile but maritime rights to Argentina . Cultural impact . Books . Several books have been written about the conflict , the Operation Soberanía and the comparison of the outcome of the Falklands and the Beagle conflict ( see Literature ) . Given that the military critical phase of both conflicts occurred whithin almost only 3 years ( Dec 1978 - April 1982 ) , the conflicts have been analysed as a case for the prospect theory or the role of the mass media in the use of force . Geography . The mountain pass of Puyehue was renamed Cardenal Antonio Samoré Pass for Antonio Samoré , one of the mediators from the Vatican state in the conflict . Art . Leon Gieco created the song " Sólo le pido a Dios " ( " I only Ask of God " ) in 1978 as a response to the warmongering in Argentina . Three years later , during the Falklands War , the Argentine junta used the song against the Falklands War after the invasion . In 2005 the Chilean movie " Mi Mejor Enemigo " ( ) was released . The film recreates the story of a simple recruit in late 1978 when both countries were on the brink of war . Three TV productions about the conflict ( in Spanish ) focus on Operation Soberanía : Economic impact . The arms race at both sides of the border after the Argentine refusal of the decision of the Court of Arbitration caused huge costs for the economy of the countries , until after the Falklands War : < br style = " clear : both ; " > Aftermath . The Beagle conflict was argued in legal and juridical terms , although it was eventually resolved as a political compromise . During the 1990s , under the presidency of Carlos Menem in Argentina and Eduardo Frei Ruiz - Tagle in Chile , they resolved almost all of their disputes and both countries began to work together both economically and militarily . A number of prominent public officials in Chile still point to past Argentine treaty repudiations when referring to relations between the two neighbors .