This book focuses on the few countries where actual transitions have happened: Tunisia, Egypt, Libya and Yemen. Syria, where the authoritarian breakdown was only partial, will also be considered. Most of the book’s contributors adopt a comparative approach, either comparing those different countries among themselves, or comparing them with other Arab and non-Arab countries with similar features (i.e., Morocco, Algeria, and even Turkey). The choice was made to focus on a limited number of themes which have not received systematic comparative attention, and which offer crucial insights into the dynamics of the Arab transitions as they took place. The first part of this book deals with the dynamics of accommodation and polarization generated by the institutional process during transitions. The second part of the volume looks at the role of militaries in the different transitions. The third part of the book looks at several non-state actors that have impacted the transitions. The last part of the volume addresses the often overlooked issue of transitional justice, or the lack thereof.