Chile–Peru relations and Angamos (Oct. 8, 1879) enabled Chile to control the sea approaches to Peru. A Chilean army then invaded Peru. An attempt at mediation by the United States failed in October 1880, and Chilean forces occupied the Peruvian capital of Lima the following January. Chile was also to occupy the provinces of Tacna and Arica for 10 years, after which a plebiscite was to be held to determine their nationality. But the two countries failed for decades to agree on what terms the plebiscite was to be conducted. This diplomatic dispute over Tacna and Arica was known as the Question
Mineral industry of Peru No. 868 of May 1996 (Texto Unico Official) provide guaranteed protections to mining ventures and contracts under the Peruvian Civil Code. Consequently, such ventures and contracts are immune from unilateral changes by any governmental authority in Peru without an appropriate legal or administrative remedy or arbitration by the Convenio Constitutivo del Centro Internacional de Arreglo de Differencias Relativas an Inversiones (Formal Consent of the International Center for Settlement of Relative Differences on Investments). Additionally, Peru enacted the Supreme Decree No. 047-2002-EF of April 2002 (import duties for capital goods) to reduce the duties paid to 7% from 20% and 12%