It is a pleasure to acknowledge many helpful conversations with James Mercer-Smith and David Sharp, both of Los Alamos National Laboratory. Hanaa Benhalim of the Defense Threat Reduction Agency provided invaluable assistance in locating photographs of U.S. weapons systems. Kathy Vinson, of the Defense Visual Information Center, was very helpful in locating images of missiles, aircraft, and submarines. Mim John offered thoughtful comments on alternative views along with many specific suggestions for improvement. I would like to recognize admirals Richard Mies and James Ellis, both former commanders of United States Strategic Command, for their leadership and vision in transforming strategic thinking. My editors at Ecco, Emily Takoudes and Greg Mortimer, and my agents, Don Lamm and Christy Fletcher, provided sage advice throughout this project. Special thanks go to my wife, Mari, for her support and critical reading of the manuscript.