1932 Invasion of Bolivia
The Paraguayan invasion took place due to the disputed territory of Chaco. The territory had been disputed between the two countries for years but in 1905 Bolivia began moving settlements into the area which was only half-heartedly opposed by Paraguay. In the years following, minor border clashes threatened war between the countries over the disputed border but neither Bolivia nor Paraguay had the military capacity to go to war. It was not until 1932 that both countries had the arms and military for the border dispute to escalate.
The two sides were very mismatched. Bolivia had three times the population and a much larger army. For Bolivia, dispute over Chaco was not worth dying for, and therefore the majority of the population was not affected by the war. For Paraguay the war became a total one; the entire military was mobilized and everyday citizens made sacrifices to support the war effort. Both Bolivia and Paraguay moved forces into the Chaco region which had previously been attributed as part of Bolivia in 1932.
In May 1933, Paraguay officially declared war on Bolivia and the fighting in the border region escalated. Paraguay made substantial gains against the Bolivian forces and the advance continued through 1934. In January 1935 the Paraguayan army moved into undisputed Bolivian territory.
Bolivian forces then gained the upper hand through aggressive counterattacks which led to a truce in June 1935. Throughout the years of fighting, 100,000 men lost their lives and the Bolivian economy suffered. The Chaco Peace Conference in 1938 gave Paraguay control over the majority of the Chaco region, but Bolivia was given a corridor that led to the Paraguay River and the port of Puerto Casado.