Peter J. Mantle, a former U.S. Navy program manager and Pentagon insider, has written this book to help decision makers sort out the costs and technical merits of competing missile defense technologies now in development or under research. Officials in the various missile defense communities tend to make claims of missile defense performance and technical risks using community specific terms and units of measure that make it difficult to compare one system to another. Mantle unravels this trend by translating competing measures into a common standard, and common treatment. He explores the history of missile defense and standardizes the confusing world of missile-defense terminology. He devotes a chapter to defining life-cycle costs, trends in budgets and the actual costs of the sub systems and components of land, sea, air, and space systems. The book is targeted not just to executive decision makers, but also anyone in the missile-defense decision chain, from Pentagon procurement officers to members of Congress to engineering managers in industry and academia. The book is organized into chapters that discuss the specific criteria decision makers should use when evaluating missile-defense hardware - including both technical factors (performance, cost, schedule and risk) as well as programmatic and political factors. Perhaps most importantly, the book concludes with chapters describing the techniques and perspectives decision makers should rely on to unemotionally and fairly evaluate missile-defense systems and technologies.