A recurring, often harrowing, problem in the arena of public health is the sudden and well-publicized emergence of threats to public health and safety, including infectious diseases and product-related hazards. AIDS, of course, is the most important example, but others include swine influenza, swine flu vaccine, and Legionnaires’ disease in the 1970s; Reye’s syndrome, toxic shock syndrome, and cyanide-laced Tylenol in the 1980s; silicone breast implants and various bacterial hazards in the 1990s. Some hazards, such as Lyme disease and chronic fatigue syndrome, persist for years. Unlike many distant or hypothetical health and environmental threats, emergent public health hazards create visible victims quickly (often after a single exposure) and raise high expectations for prompt and effective federal response. But what can government do about them? In the first book to examine the emergent public health hazard as a general problem, Christopher Foreman focuses on its often-neglected political and institutional aspects. Assessing the government’s major roles as investigator educator, regulator, researcher, and funder for these health problems, he emphasizes that federal health agencies have been regularly constrained by uncertain knowledge and external political forces. Contending that anticipatory and reactive policy reforms are often practically and politically questionable, Foreman calls for a more energetic program of disease and product surveillance to identify and track emerging problems.