It promotes new modes of political interaction, but it also disrupts interstate dealings and empowers non-state actors who may instigate diplomatic and military crises. Despite significant experience with cyber phenomena, the conceptual apparatus to analyze, understand, and address their effects on international order remains primitive. Here, Lucas Kello adapts and applies international relations theory to create new ways of thinking about cyber strategy. Kello draws on a broad range of case studies, including the Estonian crisis, the Olympic Games operation against Iran, and the cyber attack against Sony Pictures. Synthesizing qualitative data from government documents, forensic reports of major incidents and interviews with senior officials from around the globe, this important work establishes new conceptual benchmarks to help security experts adapt strategy and policy to the unprecedented challenges of our times.