it will be a war for Paraguay to the extreme. It will probably be the bloodiest war on the American continent. Especially if brazil manages to call chile to war with promises of winning the disputed lands and a few more. the Paraguayan war ended with 440,000 dead. This war will have at least twice as many, 880 thousand. It will probably be 3.5 more, giving the total dead in this war 1.408 million dead. Maybe another 200 to 250 thousand if the governments of all sides fight hard and if the nations do like solano lopez this goes to the two million easily.
this is the best map of the future of brazil. if cisplatin stays inside the empire.
Argentina in this case will basically be a puppet of Brazil. It's the only way to have tranquility in the region with uruguay in the hands of brazil
if Brazil holds on to Uruguay, takes Paraguay, and grabs Argentina Mesopotamia, you've unlocked a maritime highway into the Brazilian interior.