Would such an attack be successful? If so could this lead to an early end to the War of Triple Alliance?
http://en.wikipedia.org/wiki/Battle_of_Curupaity
P.S. could someone message me on how to shorten links?
The Paraguayan advantage in Curupaity was exactly the fact that they were in a good defensive position. If they had gone to the field they would have lost this advantage.
Now, if their victory had been even greater, it wouldn't necessarily stop the war. As long as Argentina keeps in the Allied side and the Brazilian government wanting to punish Lopez the war would continue. The only way to stop it by 1866 would be by taking Argentina out of the conflict. Maybe if Mitre is killed during the battle and his successor, Marcos Paz, had decided that making the peace would be the better option. But I'm not sure how likely is that.