This book is a collection of essays by senior defense analysts at RAND, all of whom have been deeply involved in post-Cold War defense planning studies for the Department of Defense. The essays cover a wide spectrum of issues, including alternative strategies and structures for defense planning, conventional deterrence of Third World opponents, modernizing weapon systems and force structures, and planning under uncertainty (a major theme of the book as a whole). Some of the essays are sympathetic to current U.S. methods and policies, whereas others are critical, arguing that radical changes are needed. Taken as a whole, the book provides a provocative cross section of work by experts who understand both the theoretical issues and the practical considerations that the Department of Defense must address. The book will be of interest to policymakers, students of defense planning, and other readers seeking to understand the challenges and choices confronting defense planners as we approach the end of the century.