In the late nineteenth and early twentieth centuries, the South American nations of Argentina and Chile engaged in an expensive naval arms race to ensure the other would not gain supremacy in the Southern Cone.
Although the Argentine and Chilean navies possessed insignificant naval forces in the 1860s, with zero and five warships, respectively, Argentina's concern over a strong Brazilian Navy and the Chilean war against Spain caused them to add capable warships to their fleets in the 1870s. During this time, diplomatic relations between Argentina and Chile soured due to conflicting boundary claims, particularly in Patagonia. By the beginning of the 1880s, after the War of the Pacific, the Chilean government possessed possibly the strongest navy in the Americas. They planned to add to it with an 1887 appropriation for one battleship, two protected cruisers, and two torpedo gunboats. Argentina responded a year later with an order for two battleships of its own. The naval arms race unfolded over the next several years, with each country buying and ordering vessels that were slightly better than the previous ship, but the Argentines eventually pulled ahead with the acquisition of multiple Garibaldi-class cruisers.
The race ended in 1902 with the British-arbitrated Pacts of May, which contained a binding naval-limiting agreement. Both governments sold or canceled the ships they had ordered, and three major warships were mostly disarmed to balance the fleets. The pacts proved to be the answer to the Argentine and Chilean disputes, as the countries enjoyed a period of warm relations. This did not last, though, as the Brazilian government's attempt to rebuild its own naval forces sparked another naval arms race, involving all three countries' orders for revolutionary new dreadnoughts, powerful battleships whose capabilities far outstripped older vessels in the world's navies.