*This book is in the Rapid Communications in Conflict and Security (RCCS) Series (General Editor: Geoffrey R.H. Burn). The character of not only war but also strategic competition appears to be changing. Failing to adapt will result in further losses of blood and treasure as well as prestige and influence. Power withers when it proves frail. This book by Charles Cleveland, Benjamin Jensen, Susan Bryant, and Arnel David calls for the rethinking of how the U.S. national security community approaches population-centric warfare and strategic competition in the 21st century. Strategic advantage in the 21st century will emerge from mapping human geography in a connected world, leveraging key relationships, and applying a mix of unconventional and conventional methods that put adversaries on the horns of a dilemma. The authors outline a new approach to thinking about military art rooted in increasing connectivity and defining a new domain of competition, the human domain. In the 21st