The Chaco War (1932-1935) was a conflict between Paraguay and Bolivia over control of the Gran Chaco, a region rich in resources. The war was sparked by disputes over territory and access to oil reserves. Both nations mobilized their armies, leading to significant battles and casualties. The war ended with the signing of the Treaty of Peace and Friendship in 1938, which established the borders between the two countries. Paraguay emerged as the victor, gaining most of the disputed territory. The conflict had lasting effects on both nations, shaping their military and political landscapes.