ABC countries

The term was mostly used in the first half of the 20th century, when the three countries worked together to develop common interests and a coordinated approach to issues in the region with relatively little influence from outside powers.

During the early 20th century Argentina, Brazil, and Chile engaged in a naval arms race, beginning with Brazil purchasing three dreadnoughts in response to the recently concluded Argentine–Chilean naval arms race.

On May 20, 1914, the three countries met in Niagara Falls, Ontario, Canada, to mediate between the United States and Mexico after increasing tensions over the Tampico Affair, the United States occupation of Veracruz, and developing issues that led to the Mexican Revolution.

[1] In 1942 the ABC countries, with the United States, mediated in the peace terms of the Ecuadorian–Peruvian War.

This led to the loss of all disputed territory in the Amazon Basin that had been claimed by Ecuador before the war.