In this scenario, the North American Union, comprised of Canada, the US and Mexico, has been established to counter the enormously backfired right wing government put in power by the US previously, and has begun on a path of an increasingly nationalistic agenda, denouncing not only Eastern influence in South America, but Western influence as well, especially that of the United States of America.
People are increasingly reminded of how Brazil has been thwarted from achieving prosperity, stability and world power status due to how the US sees it poses a threat to it, and how many pro US governments were installed in Spanish speaking countries such as Colombia, Argentina and Mexico, making Brazilian influence in the Americas minuscule in comparison to the power the US has.
While the NAU is busy balancing between increasing German influence in the European Union, and the unstoppable might of the SCO taking over it’s interests at every turn and at every corner of the globe, Brazil manages to seize the opportunity and create a South American Union similar to the EU, in which borders are erased, a new trade deal is proposed to the NAU which erases previous bilateral agreements between the US, Mexico and various South American countries, and insists on a gold standard across all of South America geared to be beneficial to South America.
After a failed coup attempt in Brazil and US special forces operatives are captured, NAU declares war on Brazil, confident that they still enough influence in the rest of South America to win a quick victory.