Although this brutal South American version of the Battle of Verdun lasted only three days, it cost Bolivia and Paraguay most of their elite soldiers.
It could be said that most of the troops the two countries committed to the war afterward were raw recruits who had received little training.
After Saavedra's defeat, the Bolivian army had already lost control of the front. The troops there had collapsed like a thousand-mile dike breaking, and in less than a week, Paraguay had seized more than thirty military positions.
With the front on the verge of collapse, the Bolivian army could no longer sit still. On July 27, 1931, believing itself thoroughly prepared, the Bolivian army launched a major assault on Nanawa Fortress, a Paraguayan frontline position.
Nanawa Fortress lay to the west of the Paraguayan army, protecting its flank. If it fell, not only would the Paraguayan troops fighting at the front face a threat from the flank, but the Bolivian army might also move down the river and directly threaten Paraguay's capital, Asuncion.
Paraguay naturally attached enormous importance to this extremely vital flank fortress.
The attacking Bolivian army numbered roughly forty thousand men, while the defending Paraguayan force consisted of one division, nearly seventeen thousand strong.
Although it was outnumbered, Paraguay had equipped Nanawa Fortress with large numbers of machine guns from the United Kingdom and Australasia, along with a small number of artillery pieces for fire support. This made the flank fortress extremely formidable.
After a simple assessment, the Australasian officer corps concluded that, with one division stationed there, Nanawa Fortress could withstand an assault by at least three enemy divisions.
The situation Nanawa Fortress now faced was more or less exactly the one-to-three scenario the Australasian officer corps had previously assessed.
As it turned out, the Australasian officer