Chile, Peru, and the ICJ Boundary Settlement

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On January 27, the International Court of Justice (ICJ) handed down its ruling in a border dispute between Chile and Peru.[1] The decision is an affirmation of the capacity of the ICJ to find equitable solutions to discrete international conflicts.[2] The fact that both Chile and Peru are able to claim the decision as both a compromise and a victory shows that the ICJ can be a powerful tool for improving international relations.[3]

The border dispute between Chile and Peru was a relic of the War of the Pacific, which ended with a Chilean victory over Peru, as well as Bolivia, in 1893.[4] The land boundary between Peru and Chile was later determined in the Treaty for the Settlement of the Dispute regarding Tacna and Arica, in 1929.[5] Both countries later declared overlapping maritime boundaries in a series of unilateral pronouncements, and were never able to agree on a maritime boundary.[6]

Peru brought the dispute before the ICJ in 2008, and the general populations of both countries were keenly interested in the verdict.[7] At stake were 38,000 square kilometers of sea, including significant mackerel and pilchard fisheries.[8] Both countries also saw the dispute as a matter of national pride, as relations between the two countries have been strained at times.[9]

The ICJ’s decision is largely a compromise between Chilean and Peruvian arguments.[10] While Chile claimed the maritime territory south of a line extending due west from the agreed coastal boundary, Peru claimed the territory to the north of a line extending west-south-west from the same point.[11] Peru claimed that the boundary should be determined using a method of triangulation that would fix the boundary at points based on equidistant coastal points in each country, with these markers being equidistant from the agreed land boundary.[12] This left a roughly triangular portion of disputed territory, shown in Diagram 1.[13]

Rather than award all of the disputed maritime boundary to one country, the ICJ formulated a compromise between the two positions by which the boundary extends due west for 80 nautical miles, then turns southwest along a line determined by the equidistant method advocated by Peru.[14] This essentially means that the court adopted Chile’s claimed boundary for the first 80 nautical miles extending from the coastline, and Peru’s claim for the remaining portion of disputed territory extending from 80 to 200 nautical miles out to sea, as shown in Diagram 2.[15]

As the ICJ’s Jurisdiction is entirely predicated on the parties’ consent, the court’s ability to settle contentious international disputes is somewhat limited.[16] Still, the court’s capacity to equitably settle border disputes prevents such disputes from further compromising international relations.[17] As The Economist noted, “[m]any political and business leaders on both sides see the ruling as a chance to set aside the past and intensify rapidly growing ties.”[18] Furthermore, compliance with such judgments will further encourage other countries to seek redress before the ICJ and possibly create more stability and cooperation within the region.[19]

[1] Chile, Peru and the ICJ: A Line in the Sea, The Economist (Feb. 1, 2014) available at

[2] Id.

[3] Id.

[4] Rory Carroll & Andres Schipani, Bolivia’s Landlocked Sailors Pine for the High Seas, The Guardian (Aug. 27, 2008) available at Interestingly, Bolivia still maintains a naval force of over 5000, which patrols Lake Titicaca. Id.

[5] Maritime Dispute (Peru v. Chile), Judgment, ¶ 17 (Jan. 27, 2014), available at (PDF).

[6] Id. ¶¶ 18-21.

[7] The Economist Explains Chile and Peru’s Pacific Dispute, The Economist blog (Jan. 28, 2014)

[8] Chile, Peru and the ICJ: A Line in the Sea, The Economist (Feb. 1, 2014) available at

[9] The Economist Explains Chile and Peru’s Pacific Dispute, The Economist blog (Jan. 28, 2014) (“Peruvians have long considered Chileans to be abusive and arrogant, while Chileans have seen Peruvians as perpetual whiners.”).

[10] John Quigley, International Court Splits Disputed Waters in Chile-Peru Dispute, Bloomberg (Jan. 27, 2014)

[11] Maritime Dispute (Peru v. Chile), Judgment, ¶¶ 22-24 (Jan. 27, 2014), available at (PDF).

[12] Id. ¶¶ 184-187

[13] See id. ¶¶ 22-24 & 184-187.

[14] Id. ¶¶ 194-197.

[15] Id.

[16] Maura A Bleichert, Comment: The Effectiveness of Voluntary Jurisdiction in the ICJ: El Salvador v. Honduras, A Case in Point 16 Fordham Int’l L.J. 799, 803-807 (1993).

[17] Chile, Peru and the ICJ: A Line in the Sea, The Economist (Feb. 1, 2014) available at

[18] Id.

[19] Id.

Posted by Peter H. Webb (Pete) on Mon. February 24, 2014 8:00 AM
Categories: Chile, International Court of Justice, Latin America, Peru, Territorial disputes

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