Brazil is frequently described as a continental colossus, combining vast territory, population, and economic weight with a distinctively pacifist profile. The absence of external threats has redirected its security concerns inward, privileging territorial integrity, resource protection, and development over traditional forms of power projection. In this context, diplomacy has emerged as Brazil’s main instrument of influence, expressed in sustained multilateral protagonism and the aspiration to a permanent seat on the United Nations Security Council. Equally distinctive is Brazil’s capacity to recalibrate its geopolitical horizons—shifting from pan-Americanism to the Southern Cone, South America, Latin America, and the South Atlantic—in order to consolidate regional authority and expand its strategic environment. This chapter analyzes Brazil’s dual role as a regional and global actor by tracing its geopolitical trajectory across the Cold War, post-Cold War, and contemporary contexts. We assess the country’s resources, strategies, and effectiveness, considering the structural and domestic challenges shaping its future international position.