de Antofagasta" (CSFA), a Chilean mining company, signed a contract with the government of Bolivia, in which taxes were removed from mineral exploitation for 15 years. This contract was not ratified by the Congress of Bolivia, which was then analyzed negotiations with Chile. War of the Pacific In 1873 Bolivia signed a secret treaty of defensive alliance with Peru. This would be used as an argument 5 years later in Chile, when it unleashed the War of the Pacific. The secret alliance forbade Bolivia from signing a border treaty with Chile, without consulting with Peru. However, in 1874 Chile and Bolivia signed a border treaty, which replaced the previous treaty of 1866. One of its points was not to impose new taxes on individuals, industries and Chilean capital for 25 years. For Bolivia, the contract of 1873 between the government and CSFA was not yet in force, because, according to the Bolivian constitution, all contracts with the Bolivian government had to be approved by the congress. According to the Bolivian version of events, the contract with the saltpeter company was incomplete so the congress, to approve the contract, decided to enforce a tax of 10 cents, which did not violate the treaty of 1874, since the contract was not yet in force at that date. Bolivia suspended the tax in deference to the government of Chile, but following a note from the Chilean foreign minister, it reactivated the tax law, then cancelled and closed the "Compañía de Salitres". Faced with a looming conflict with Chile, Bolivia decided to claim support under the agreement signed with Peru, and the treaty became effective with the Chilean occupation of Antofagasta, on 14 February 1879. According to the Chilean version of events, the tax of 10 cents violated the treaty of 1874 since according to this, new taxes should not have been imposed on Chilean companies operating in Bolivia. At the breaking of the boundary treaty by Bolivia, and the cancellation of the contract of the CSFA, Chile seized Antofagasta, then in Bolivian territory, whose sovereignty had been ratified before 1866. After the war, a pact of truce was signed between Bolivia and Chile in 1884, which stated that the territory between the Loa River and parallel 23 would be under the administration of Chile, while Bolivia would be allowed access to the ports of Arica and Antofagasta. However, both treaties left outstanding issues