Geopolitics explained is a framework for understanding how nations act on the world stage; this holistic view connects geography, power, and perception to reveal why leaders choose one path over another, often balancing competing interests, risks, and opportunities that unfold across regions, markets, and security architectures today and in the future.In this introductory piece, we unpack how decisions ripple through markets, alliances, and security architectures, and we show how geopolitical decision-making shapes policy across continents, influencing energy choices, trade routes, technology competition, and diplomatic signaling as leaders navigate alliances, sanctions, and strategic deterrence, drawing on case studies from recent crises, and highlighting how policymakers balance political capital with strategic consequences.