We are living in turbulent times, witnessing renewed international conflict, resurgent nationalism, declining multilateralism, and a torrent of hostile propaganda. How are we to understand these developments and conduct diplomacy in their presence? Nicholas J. Cull, the distinguished historian of propaganda, revisits the international media campaigns of the past in the light of the challenges of the present. His concept of Reputational Security deftly links issues of national image and outreach to the deepest needs of any state, rescuing them from the list of low-priority optional extras to which they are so often consigned in the West. Reputational Security, he argues, comes from being known and appreciated in the world. With clarity and determination, Cull considers core tasks, approaches, and opportunities available for international actors today, including counterpropaganda, media development, diaspora diplomacy, cultural work, and – perhaps most surprisingly of all – media disarmament. This book is crucial for all who care about responding to the threat of malign media disruption, revitalizing international cooperation, and establishing the Reputational Security we and our allies need to survive and flourish. Reputational Security is enlightening reading for students and scholars of public diplomacy, international relations, security studies, communications, and media, as well as practitioners.