The book *The New Transnational Activism* by Sidney Tarrow is a significant contribution to the theoretical foundation of research on transnational social movements. It explores the interactive relationships between states, international institutions, and non-state actors, emphasizing the underlying processes and mechanisms that shape global politics. Building on Tarrow’s earlier work *Dynamics of Contention*, the book provides a theoretically driven analysis of various cases of transnational activism, including those of the Zapatistas, European women’s rights lobbies, indigenous peoples, radical Islamic groups, Gandhians, and labor activists. Tarrow identifies six key processes in transnational politics—global framing and internalization, diffusion and scale shift, externalization, and transnational coalition formation—and discusses several mechanisms that shape these processes. The book offers insightful discussions of new research and introduces concepts such as the “rooted cosmopolitan,” which highlights the role of individuals as bridges between local contexts and global politics. However, the reviewer notes that Tarrow’s failure to systematically test his claims and his skepticism about the long-term sustainability of transnational activism, particularly in the post-9/11 era, are shortcomings. Despite these criticisms, the book remains a valuable contribution to the field, stimulating productive debate and discussion.The book *The New Transnational Activism* by Sidney Tarrow is a significant contribution to the theoretical foundation of research on transnational social movements. It explores the interactive relationships between states, international institutions, and non-state actors, emphasizing the underlying processes and mechanisms that shape global politics. Building on Tarrow’s earlier work *Dynamics of Contention*, the book provides a theoretically driven analysis of various cases of transnational activism, including those of the Zapatistas, European women’s rights lobbies, indigenous peoples, radical Islamic groups, Gandhians, and labor activists. Tarrow identifies six key processes in transnational politics—global framing and internalization, diffusion and scale shift, externalization, and transnational coalition formation—and discusses several mechanisms that shape these processes. The book offers insightful discussions of new research and introduces concepts such as the “rooted cosmopolitan,” which highlights the role of individuals as bridges between local contexts and global politics. However, the reviewer notes that Tarrow’s failure to systematically test his claims and his skepticism about the long-term sustainability of transnational activism, particularly in the post-9/11 era, are shortcomings. Despite these criticisms, the book remains a valuable contribution to the field, stimulating productive debate and discussion.