Ok, a second attempt at this one. Here's an updated backstory. When it comes out in 2015 that president Dilma Rouseff has been funneling billions of Reais from the national budget and from state-run Petrobras to fund an illicit nuclear weapons program, the nation is outraged, and she is removed from office. Though the northern half (more agricultural, rural) tends to a more peacable outlook, the southern, more metropolitan states are more inclined to take matters into their own hands. When Argentina, Chile, and Paraguay announce that they will be occupying key Brazilian cities to ensure nuclear disarmament, the Brazilian government does nothing -- and the southern states revolt.
After successful raids in São Paulo, the new Republica Rio-Grandense begins to push back on its occupiers. These southern Spanish states, not expecting anything more than a few thousand soldiers in occupation, are caught by surprise and quickly pushed back. RRG takes control of Uruguay and signs a peace accord with Bolivia to split Paraguay between the two of them. At this point, the United States and Britain step in with more than just condemnation, and send troops to Brazil and Argentina, respectively. But with the threat of nuclear war dangling over the continent, and the whispers of Chinese backing, RRG and Bolivia quickly extract peace treaties from vanquished foes. Additionally, large tracts of Central Brazil remain under military control as the transitional Brazilian government is unwilling to commit to a costly war. An uneasy ceasefire is enacted.
Meanwhile, in the north, Colombia takes advantage of the chaos to move troops into Brazil's large Amazon holdings. This terrifies the US, who is dependent on Brazilian exports such as rubber. In response, the United States lands troops in Guyana (the closest port city to the warzone) and occupies the Brazilian state of Amazonas. When it becomes clear that the remnants of Brazil have no force or power to maintain a hold on this area, the United States cedes control to Guyana, and backed by the US, the new country of Amazonas is created. Amazonas quickly receives international support, due to the vast natural resources found there.
In the South, Chile has been subjugated and Brazil and Argentina are still being propped up by foreign powers. With China's economic muscle behind the two new empires, Bolivia and RRG solidify their hold on the continent. RRG sets to work at the difficult task of uniting a country where Portuguese, Spanish, and Guarani are all official languages. An informal caste system emerges, with ethnic Brazilians at the top. Huge resettlement programs take place, with millions of poor families leaving São Paulo, Rio de Janeiro, and other RRG cities for the South American pampas. The status of the RRG nuclear weapons program is unknown, but they have taken advantage of their new base in the Falkland islands to test long-range missiles, which could, in theory, reach the coast of Africa or Central America. The peace holds...for now.
