League of Nations
Chaco War

The League failed to prevent the 1932 war between Bolivia and Paraguay over the arid Gran Chaco region. Although the region was sparsely populated, it contained the Paraguay River, which would have given either landlocked country access to the Atlantic Ocean, and there was also speculation, later proved incorrect, that the Chaco would be a rich source of petroleum. Border skirmishes throughout the late 1920s culminated in an all-out war in 1932 when the Bolivian army attacked the Paraguayans at Fort Carlos Antonio López at Lake Pitiantuta. The war was a disaster for both sides, causing 57,000 casualties for Bolivia, whose population was around three million, and 36,000 dead for Paraguay, whose population was approximately one million. It also brought both countries to the brink of economic disaster. By the time a ceasefire was negotiated on 12 June 1935, Paraguay had seized control of most of the region, as was later recognised by the 1938 truce.

Initially, both sides refused to allow the League to conduct an inquiry until November 1933, over a year after the start of the war. As a result, the League did not formally invoke Article 16 to apply sanctions. The Pan-American Conference offered to mediate and the League deferred to the conference, but the warring sides ignored the conference. Eventually (without going through Article 16), an arms embargo was enacted by several members of the League (plus non-League members the United States and Brazil), but several neighboring states ignored the embargo rendering it ineffective. In November 1934, the League demanded that both sides withdraw and undergo arbitration. Bolivia accepted, but Paraguay by then had taken control of all of the disputed area. Paraguay rejected arbitration and quit the League.
length_constraints:number_paragraphs[3]