The first two chapters of the book develop the theoretical foundation of the book. Chapter 1 focuses on the range of political, institutional, cultural, and practical variables that influence police strategic and tactical approaches to managing crowds that gather for various types of events, including social and political protests. It also examines the ways that particular police behaviors may increase or decrease the likelihood that violence or disorder will occur in a public gathering. These themes are considered further in chapter 2, which reviews relevant theories of public disorder as a basis for understanding the implications of particular contexts and dynamics of police-citizen interaction for the eruption and escalation of conflict. Subsequent chapters use case studies of particular events in outlining lessons learned for the improved policing of crowds at public events. Chapters 3-7 each incorporate case studies of significant contemporary examples of public disorder that occurred from 1991 to the present in Great Britain and America. These cases illustrate and augment the theoretical discussions of chapters 1 and 2. The case studies encompass American and British urban riots during the years 1991-2001; worldwide “anti-globalization” protest, post-Seattle; the G8 Justice and Home Affairs Ministers” meeting in Sheffield, England (June 2005); and English football fans abroad, 1990-2006. Chapter 8 draws policy implications. A central implication is that participants in the event must view police as neutral professionals whose role is to maintain order by preventing and controlling factors that can cause violence and disorder without regard to the pros and cons of positions espoused by the crowd. 4 figures, 3 tables, and 238 references