The key point of this book is that '… protests can matter a great deal, but not by themselves, and not in ways activists intend' (p. 5). The question of effects is most important but difficult to pin down with precision, and therefore understudied. The first chapter asks why movements emerge, emphasizing that context matters as much, if not more, than the choices of activists, for their success. Chapter 2 focuses on movements that pursue regime change and the extraordinary challenges of transitioning from (often violent) opposition to governance. Next, Meyer turns to movements in democratic states, most often pursuing specific – yet absolute – aims that are never accommodated in full. Chapter 4 zooms in on how movements alter the way politics is made, inspiring the foundation of new state institutions, the formation of lasting non-state organizations who lobby and monitor government actors, and the representation of movement actors in policy making and implementation. Chapter 5 discusses the impact of movements on the political awareness of activists, their symbols and their language, and their networks (which often become the foundation for other movements). Chapter 6 examines how the impacts of movements are ultimately understood, recognizing the attraction of drama and confrontation, the challenge of gaining credit for partial realization of absolutist goals, and the imminent conflict of history-writing. Meyer’s book is extremely valuable, offering a nuanced understanding of the impacts of social movements, connecting a focus on outcomes with the core themes in social movement theory, all presented in a very accessible manner. The distinctions between the opportunities that movements face in democratic versus autocratic states, as well as between movements pursuing regime change versus those pursuing reforms, are particularly useful.