The Brazilians are a nation in the Cold War CtW , and are based in their eponymous territory of Brazil. They are essentially a rehash of the Iroquois civilisation, thus they are somewhat dangerous as their units are essentially invisible within their own borders.
Because of the strategic location of their home turf between Colombia to the north and Western Africa across the sea, the Brazilians will be taken out sooner or later to secure this vital bridgehead. Another good reason to take them out quickly is because they along with the three other major nations of Latin America form a four-territory continent that can be flagged for an easy 80 tribute (in addition to whatever bonus cards they already possess). Seizing them and inducting them into your New World Order elicits a Civics Eureka card which can be used to further your cause elsewhere.