Chaco War

Chaco War
Part of the interwar period
Map of the Chaco War, showing important forts, military outposts, cities, and the Paraguayan advance to the west
Date 9 September 1932 – 12 June 1935 (2 years, 9 months and 3 days) Location Chaco Boreal, South America Result Paraguayan victory[1] Territorial changes Most of the disputed area awarded to Paraguay
Belligerents
Paraguay	Bolivia
Commanders and leaders
Eusebio Ayala José Estigarribia	Daniel Salamanca José Luis Tejada Hans Kundt Enrique Peñaranda
Strength
150,000[2]	210,000[2]
Casualties and losses
35,000–50,000 killed[3][4] 2,556 captured[5]	50,000–80,000 killed 40,000 wounded 21,000 captured[6][7][5]

The Chaco War (Spanish: Guerra del Chaco, Guarani: Cháko Ñorairõ^[8]) was fought from 1932 to 1935 between Bolivia and Paraguay, over the control of the northern part of the Gran Chaco region (known in Spanish as Chaco Boreal) of South America, which was thought to be rich in oil. The war is also referred to as La Guerra de la Sed (Spanish for "The War of Thirst") in literary circles since it was fought in the semi-arid Chaco. It was bloodiest war between two countries in South America in the 20th century and the first war in South America fought with machine guns, tanks and airplanes.

During the war, both landlocked countries faced difficulties shipping arms and supplies through neighbouring countries. Bolivia, in particular, faced external trade problems and poor internal communications. Although Bolivia had lucrative mining income and a larger and better-equipped army, a series of factors turned the tide against it, and Paraguay controlled most of the disputed zone when the war had ended.

The peace treaties ultimately granted two-thirds of the disputed territories to Paraguay.