Thierry de Montbrial, founder and President of the French Institute of International Relations (IFRI) since 1979, in his influential book The Age of Conflicts, seeks to construct an innovative framework for the study of international relations by linking classical geopolitical theories with the pressing challenges of the twenty-first century. Drawing on the intellectual legacies of Mackinder, Mahan, and Spykman, Montbrial expands the scope of analysis beyond state-centric paradigms to include economic, social, technological, and security dimensions, while emphasizing the enduring relevance of geographical determinants. His main contribution lies in combining historical reflection with forward-looking analysis, thereby providing multidimensional tools for interpreting contemporary dynamics such as the rise of non-state actors, hybrid threats, and shifting power alignments. Nevertheless, Montbrial’s approach is not without limitations: its predominant macro-level orientation risks underestimating the role of local actors, social movements, and cultural–identity factors in shaping conflict trajectories. From this perspective, The Age of Conflicts simultaneously functions as both a valuable guide to the complexities of modern geopolitics and a stimulus for critical debate and theoretical rethinking. Rather than offering closure, the work opens new avenues for inquiry into the uncertain future of global order.