This work examines how the navies of Great Britain, the USA, Germany, Japan, the Soviet Union, France and Italy confronted the various technological changes posed during different periods in the 20th century. The 20th century was the technologically most dynamic period in naval history. Changes ranging from submarines and airpower to space platforms, dramatically altered assumptions about the future of naval warfare. The different sections in this volume, which cover the years before World War I, before World War II, during the Cold War, and even into the medium-term future, discuss how the great naval powers integrated these different changes into their warship building and war planning. It is without doubt one of the crucial issues that has confronted and will continue to confront naval planners. The proper integration of technological advances has been perhaps the most important element in determining the course of naval power over the past 100 years.