Chaco War

From Conservapedia

The Chaco War of 1932-35 was a conflict fought between Paraguay and Bolivia over control of the Gran Chaco, a vast, arid and inhospitable region of South America. Prior to the war, no definitive boundaries dividing the Chaco existed, and both nations were attempting to increase their influence by the construction of military outposts. In addition, Bolivia - deprived of its Pacific coastline after defeat in war by Chile - was seeking an outlet on the navigable Paraguay River; and it weas also believed (incorrectly) that the Chaco contained valuable oil reserves.