Chaco War

The Chaco War (Spanish: "Guerra del Chaco", Guarani: "Cháko Ñorairõ") was fought from 1932 to 1935 between Bolivia and Paraguay. They fought over the control of the northern part of the Gran Chaco region (known in Spanish as "Chaco Boreal"). The war is also referred to as "The War of Thirst" in literary circles since it was fought in the semi-arid Chaco.
The peace treaties gave two thirds of the disputed territories to Paraguay.