Sidney Tarrow's *The New Transnational Activism* is a significant contribution to the study of transnational social movements, extending theoretical foundations by examining interactions between states, international institutions, and non-state actors. The book builds on Tarrow's earlier work, *Dynamics of Contention*, and offers a more theoretically-driven analysis of transnational activism. Tarrow synthesizes various scholars' work to analyze cases such as the Zapatistas, European women's rights lobbies, and radical Islamic groups, exploring six key processes in transnational politics: domestic (global framing and internalization), transnational (diffusion and scale shift), and fusion (externalization and coalition formation). He identifies mechanisms shaping these processes. The book provides insightful discussions and concepts that can aid future theory-building and hypothesis testing. However, the author's failure to systematically test claims and the confusing distinctions between national and international levels are criticisms. Tarrow's treatment of national and international spheres as dichotomous is also questioned, as well as his skepticism about the future of transnational activism, particularly after 9/11. His claim that transnational activism may decline is not theoretically grounded, and he overlooks evidence of sustained global justice activism. Despite these flaws, Tarrow's work stimulates debate and offers important questions for scholars. He encourages thinking about how U.S. power affects transnational social change and the complexities of militarism and war in transnational organizing. Overall, the book is a valuable contribution to the field, though it has areas for improvement.Sidney Tarrow's *The New Transnational Activism* is a significant contribution to the study of transnational social movements, extending theoretical foundations by examining interactions between states, international institutions, and non-state actors. The book builds on Tarrow's earlier work, *Dynamics of Contention*, and offers a more theoretically-driven analysis of transnational activism. Tarrow synthesizes various scholars' work to analyze cases such as the Zapatistas, European women's rights lobbies, and radical Islamic groups, exploring six key processes in transnational politics: domestic (global framing and internalization), transnational (diffusion and scale shift), and fusion (externalization and coalition formation). He identifies mechanisms shaping these processes. The book provides insightful discussions and concepts that can aid future theory-building and hypothesis testing. However, the author's failure to systematically test claims and the confusing distinctions between national and international levels are criticisms. Tarrow's treatment of national and international spheres as dichotomous is also questioned, as well as his skepticism about the future of transnational activism, particularly after 9/11. His claim that transnational activism may decline is not theoretically grounded, and he overlooks evidence of sustained global justice activism. Despite these flaws, Tarrow's work stimulates debate and offers important questions for scholars. He encourages thinking about how U.S. power affects transnational social change and the complexities of militarism and war in transnational organizing. Overall, the book is a valuable contribution to the field, though it has areas for improvement.