Bolivia and Paraguay formalize their border after 88 years

On September 17, 2026, the governments of Bolivia and Paraguay officially formalized their international border in La Paz, concluding a complex process that spanned 88 years. The final agreement followed three days of intensive work by a joint border demarcation commission, which utilized modern drone technology and historical government records to map remote sections of the approximately 755-kilometer frontier.

This development marks the definitive end of the historical fallout from the Chaco War, which took place between 1932 and 1935 over control of the northern Chaco region. That conflict resulted in 80,000 to 100,000 deaths and led to Bolivia losing territory equivalent to more than half of Paraguay’s current land area. A 1938 peace treaty initially set the path for the long-term demarcation process that has now reached its successful conclusion through the work of bilateral technical committees.