Nationalism has re-emerged as a defining force in global affairs, influencing economic decisions and international relations at an unprecedented scale. In this expanded INFER Brief, we delve into the comprehensive research of Tao and Saadaoui (2025), exploring how nationalism’s resurgence is shaping economies, altering environmental outcomes, and challenging established paradigms of global cooperation. Building on their study of 193 countries between 1979 and 2013, we expand the discussion with historical context, detailed mechanisms, real-world case studies, and practical recommendations for a sustainable and inclusive future.