Over more than ten years of continuous combat, the United States Army has proven itself in some of the toughest environments it has ever faced. It has been an army in transition, carefully balancing the pillars of manpower, readiness and modernization to keep ahead of its adversaries in the field while guaranteeing strategic flexibility as the nation’s force of decisive action on a global scale. Despite every challenge, it has transformed into the most seasoned, deployable and spirited land force in the world today.The experience of more than a decade at war has taught the Army that it faces hybrid threats around the world. Hybrid threats—those that combine capabilities of state and nonstate actors, traditional and emerging military technology, conventional and electronic domains—define what has come to be known as the security paradox of our time. Even though much of the world is at peace on a macro scale, it has become possible in this century for a far greater number of potentially hostile actors to challenge American security and American interests in an infinitely greater number of ways. As the national security establishment rebalances toward the Pacific region and continues to prepare to meet complex operational challenges globally, the Army’s role has never been more fundamental in actively preventing the outbreak of conflict via its ready posture, shaping the complex operational environment through its partners and allies and preparing to win decisively whenever the nation might call.Central to the preservation of American security in this complex environment are the actions that the Army has undertaken to be able to conduct truly unified land operations—the ability to gain and maintain operational advantages to create the conditions for favorable conflict resolution. Operational testing and evaluation is not a new concept for the Army; it has dedicated significant resources to this integral function for many decades. Among the most crucial lessons of war was that the Army needed an institutional mechanism for developing, evaluating and acquiring modern technology rapidly to keep pace with agile enemies’ capabilities. That mechanism resides in the Network Integration Evaluation (NIE) and the larger Agile Capabilities Life Cycle Process (the Agile Process), a holistic approach that efficiently identifies commanders’ requirements, integrates Soldiers with industry to develop rapid solutions to urgent challenges and provides new equipment to Soldiers in the field swiftly enough to be useful in the current fight. Traditionally, the Army had to identify units through the Test Schedule and Review Committee process to test systems one by one. But this new unified approach that combines rapid operational testing, acquisition and deployment has already proved to be a significant step forward for the Army in terms of both expanded responsiveness to security challenges and cost savings.Led by U.S. Army Test and Evaluation Command (ATEC)—which has the distinct advantage among the service operational test agencies of having developmental testers, operational testers and system evaluators organized under one command—the Army is now on the cusp of leveraging this success into an even broader evolution in capability by expanding the NIE concept farther. All over the world, ATEC independently tests, assesses and evaluates equipment, systems and technology in laboratories and realistic operational environments using typical Soldiers to determine effectiveness, suitability and survivability.