This introductory chapter poses the book’s main questions, surveys the literature on the Arab Spring, places the Arab Spring in historical and comparative perspectives, introduces the book’s explanatory framework and methodology, and provides an overview of the book. Of the countries involved in and affected by the Arab Spring protests, why was Tunisia the only country to embark on a procedural and consensual democratic transition? Why not Egypt? Why did the Bahraini monarchy call on outside military assistance to repress the protests, while the Moroccan monarchy quickly agreed to constitutional amendments? Why did Libya, Syria, and Yemen descend into internationalized civil conflicts? More broadly, what prevented a region-wide democratic transition? We present our thesis regarding the salience of type of state, civil society, gender relations and women’s mobilizations, and international influences in shaping transition possibilities and trajectories. Tables and figures illustrate the argument and situate the 2011 uprisings along a historical continuum of protest and mobilization in the MENA region.