The Army is the cornerstone of the nation’s security. For more than 237 years, it has stood ready—deterring potential adversaries, influencing the course of international relations and dominating the battlefield when called upon to act in the nation’s interest. These roles will endure long into the future. However, the global security environment becomes more challenging and unpredictable every day, and the combinations of forces that can align to threaten the United States continue to increase.The revised “The U.S. Army Capstone Concept” (U.S. Army Training and Doctrine Command Pamphlet 525-3-0), released in December 2012, presents the Army’s initiative to transition into a force based predominantly in the continental United States (CONUS) but ready and able to deliver a wide array of expeditionary capabilities rapidly when needed. The Army Capstone Concept (ACC) serves as a guide to how the Army will employ its resources to confront an uncertain future and offers an outline for comprehensive investment in Army force structure, modernization and readiness in accordance with national strategy guidance.