Introduction
The Introduction discusses the emergence of physical violence in protests as a surprising outcome and shows how such outcomes emerge due to situational breakdowns—patterns taking place while the event itself is unfolding. It compares the relevance of situational dynamics for surprising outcomes, collective behavior, and individual action to that of background factors, such as motivations, strategies, and culture. It starts by discussing the 2007 Rostock G8 protest march, which turned violent despite all planning and expectations of the event staying peaceful and regardless of a “soft” police strategy. It then examines the 2009 Kehl NATO protest march, which stayed peaceful despite expectations of violence, a harsh police strategy, and individual protesters trying to escalate the situation. The Introduction also provides an overview of what is to come in the book, summarizing how situational breakdowns can explain a variety of surprising outcomes, from protest violence to violent uprisings and failed armed robberies.