War of The Pacific

The War of the Pacific (Spanish: Guerra del Pacífico) took place in western South America from 1879 through 1883. Chile fought against Bolivia and Peru. Despite cooperation among the three nations in the Chincha Islands War, disputes soon arose over the mineral-rich Peruvian provinces of Tarapaca, Tacna, and Arica, and the Bolivian province of Antofagasta. Chilean enterprises, which largely exploited the area, saw their interests at stake when Peru nationalized all nitrate mines in Tarapaca, and Bolivia imposed a 10-cent tax on the Antofagasta Nitrate & Railway Company. The foundations of the conflict were laid in a dispute between Chile and Bolivia over part of the Atacama Desert.

The war began on February 14, 1879 when Chilean armed forces occupied the port city of Antofagasta, after a Bolivian threat to confiscate Chilean Antofagasta Nitrate Company's property. Peru attempted to mediate, but when Bolivia announced that a state of war existed, the situation deteriorated. Bolivia called on Peru to activate their mutual defense pact, whereas Chile demanded that Peru immediately declare its neutrality. On April 5, after Peru resisted both demands, Chile declared war on both nations. The following day, Peru responded by acknowledging the casus foederis.

This "Saltpeter War" took place over five years in a variety of terrain, including the Atacama Desert and Peru's deserts and mountainous regions. The war's first battle was the Battle of Topáter. For most of the first year the focus was on the naval campaign, as Chile struggled to establish a sea-based resupply corridor for its forces in the world's driest desert. The Peruvian Navy met initial success, but the Chilean Navy prevailed. Afterwards, Chile's land campaign bested the badly equipped Bolivian and Peruvian armies, leading to Bolivia's complete defeat and withdrawal in the Battle of Tacna on May 26, 1880, and the defeat of the Peruvian army after the Battle of Arica on June 7. The land campaign climaxed in 1881, with the Chilean occupation of Lima. The conflict then became a guerrilla war engaging Peruvian army remnants and irregulars. This Campaign of the Breña was fairly successful as a resistance movement, but did not change the war's outcome. After Peru's defeat in the Battle of Huamachuco, Chile and Peru signed the Treaty of Ancón on October 20, 1883. Bolivia signed a truce with Chile in 1884.

Chile acquired the Peruvian territory of Tarapacá, the disputed Bolivian department of Litoral (cutting Bolivia off from the sea), as well as temporary control over the Peruvian provinces of Tacna and Arica. In 1904, Chile and Bolivia signed the "Treaty of Peace and Friendship" establishing definite boundaries. The situation between Chile and Peru worsened when the 1893 plebiscite to determine the fate of the provinces of Arica and Tacna was not held. Colonization and violent Chileanization of the territories resulted in a break of relations in 1911. The 1929 Tacna–Arica compromise gave Arica to Chile and Tacna to Peru, but did not resolve the antipathy. Later political problems among these neighbors often referred back to this conflict.