The Chaco War, 1932-1935, fought between the South American nations of Paraguay and Bolivia, was one of bloodiest conflicts of the inter-war era and the largest fought in South America during the 20th century. More than 100,000 soldiers perished in the struggle for roughly 250,000 square miles of unforgiving terrain, known also as the Chaco Boreal, on the shared border with Paraguay, Bolivia, Argentina, and Brazil. Beginning as a 19th century territorial dispute, the diplomatic situation in the Chaco had been unstable in the late 1920's, especially after Standard Oil had discovered large reserves of oil in the region. Following the destruction of the Bolivian fort at Vanguardia in 1928, both nations prepared for war. The long standing dispute between Bolivia and Paraguay escalated in June of 1932 into a complex and large scale conflict, the bloodiest in modern South American history. Both Argentina and Royal Dutch Shell had a stake in the dispute, with who would control the flow of oil out of the Chaco, a vital question which had to be settled by the warring nations.
Before the conflict in the Chaco, Paraguay had a small standing military force and lacked for officers after the bloody civil war of 1922-1923 but the country managed to rapidly mobilize, although finances were an issue for the landlocked country. Not to be outdone by the Bolivians, Paraguay purchased armaments and received training from European and local advisors, principally Argentina and France, and sought the aid of additional foreign advisors for technical support. No armored vehicles were procured by Paraguay until the end of the Chaco War, in fact, the most important motorized vehicle to the Paraguayan war effort were the over 800 Chevrolet trucks imported and assembled before hostilities had begun. These trucks were vital in carrying weapons, ammunition, and water to the frontlines. Trucks were also operated for casualty evacuation and prisoner of war transport by the Paraguayans.