This book is tied to two threads in my previous work. I studied filmmaking in college, and have long been fascinated by film as a physical medium: what it feels like, what it smells like, how it changes when we process or expose it in a certain way—questions that mostly have to do with chemistry. Second, much of my research has focused on the intersections between film and the military, and my first book explored the emergence of an experimental film culture in the socialist Czechoslovak Army’s film studio. When I came across a mention, in the archives, of Kodak’s work for the Manhattan Project, it brought these threads together.These threads are linked to some of the larger ideas the book relates to. Thinking of film and the military, for example—not war films, but film as something that has, since its earliest years, been entwined with military industries, institutions, and cultures—emphasizes how limiting traditional definitions of “film” can be. This is an idea that film and media historians have explored over the past two decades or so, by looking at film and media practices and cultures that on first glance seem to have little to do with “entertainment” or “communication” or “art,” but play crucial roles in our world. Tales of Militant Chemistry takes this line of thinking in a slightly different direction. It postpones the idea of a finished film (again, something we might watch in a cinema) and thinks instead of how what’s often called “raw” film has shaped the world—and, in turn, how it has been shaped by the world.Thinking of film as a “raw” substance also emphasizes its physical dimensions, which points to another set of ideas with which the book is in dialogue. These have to do with what’s often called materiality in the humanities and social sciences. Materiality is a big tent. It encompasses things like physical materials and characteristics, as well as social, political, economic, and environmental questions. In this book, I’m interested in tracing the historical relationships between these aspects of film’s materiality. In particular, the book holds that looking at things like the gelatin, cotton, silver, coal, and wood (some of film’s raw materials), and the ways they were sourced, processed, moved, and sold, reveals not just new industrial aspects of film’s history, but also a larger history of military, colonial, racial, and environmental violence. This is a history that exceeds any kind of national framework—that is, it isn’t only a Kodak history or a US history; it is a history that was always transnational, and must be narrated in this way.