In this research study, former Defense Department consultant George Refuto traces the technological evolution of USAF long-range strategic nuclear bomber aircraft during and after the Cold War, as well as the development of their missions and utilization of US nuclear bombers in 21st century regional and global military threat scenarios. Five distinct periods are covered in this study: World War I (1914-1918), the Interwar Period (1919-1939), World War II (1939-1945), the Cold War (1946-1991), and the Post-Cold War Period (1991-present), with an emphasis on the latter two. In his writing, Refuto focuses on developing a model that encompasses bombing and air defense for each period, and showing how concepts, technologies, and implementations of strategic bombing have changed and influenced the current level of development of the USAF strategic nuclear bomber force and doctrine, and what is projected for the future. About the Author George J. Refuto is a former Defense Department consultant who has extensive academic and professional experience in the fields of military history, weapon systems technology, intelligence-surveillance-reconnaissance systems, and US national security/defense policy. He has worked in both the defense and intelligence communities, and holds a master's degree in International Affairs from Columbia University, with specializations in US/USSR strategic and theater/tactical nuclear forces, undersea and airborne naval weapons systems, and Russian-Soviet politics. He has previously published Evolution of the US Sea-based Nuclear Missile Deterrent: Warfighting Capabilities and is working on a third book on the US ICBM deterrent.