The return of the Taliban has undermined EU external action, reversed twenty years of state-building efforts and represents the most significant failure of EU foreign policy to date. Drawing on over 100 hours of interviews with key actors and an in-depth examination of the EU’s state-building efforts, this book offers unparalleled insights into the complex interplay between transatlantic relations and the resurgence of the Taliban. It critically evaluates the EU’s strategies, advocating for a nuanced, historically informed approach to international relations. Indispensable for academics, policy makers and anyone vested in the intricacies of foreign interventions in an ever-complex global environment.