Seldom in U.S. history has our Army been required to respond to the range of scenarios and missions like those posed by the Global War on Terrorism (GWOT). In “Serving a Nation at War,” Acting Secretary of the Army Les Brownlee and U.S. Army Chief of Staff General Peter Schoomaker in present a vision for a new force, as well as methods to achieve it, by seeking to organize forces temporally for this new operational environment. The content and capability of the Army today was determined by previous strategic outlooks and constraints. So, the Army remains structured with relatively large formations built for large, mature theaters of war and an operational strategy of building up formations over time. Now, newly designed principles of modular force capabilities will aid leaders in making the Army the expeditionary force so necessary to fight the GWOT and future wars. The need to clarify mobilization timelines and policies prompted the Army Reserve to move from tiered readiness and linear deployment models toward smaller, capabilities-based deployable teams. The concept came to be called the Army Reserve Expeditionary Force (AREF), contributing to that part of the Army that will be expeditionary.Consistent with our history and culture, military expeditions have served the national interest when world situations called for them. During much of the 19th and early 20th centuries, the Army provided most of the U.S. expeditionary forces for the Mexican War, the Spanish-American War, the Boxer Rebellion, the Philippine Insurrection, the First World War and the post-World War interventions in Russia. The U.S. Army transformed into a force oriented for major wars during the Second World War, while the expeditionary aspect of American military operations shifted to the U.S. Navy and Marine Corps. More recently, this expeditionary role has also belonged to the U.S. Air Force. Meanwhile, the U. S. Army has been relied upon principally for staying power and building campaign quality forces. Now, the Army must be reconfigured into The Landpower Essay series is published by AUSA’s Institute of Land Warfare. The series is designed to provide an outlet for original essays on topics that will stimulate professional discussion and further public understanding of the landpower aspects of national security. The content represents the personal opinions of the author and not necessarily the position of the Association of the United States Army or its members. Candidate essays of 5,000 words or less may be submitted to: AUSA’s Institute of Land Warfare, ATTN: Landpower Essay Series, 2425 Wilson Boulevard, Arlington, VA 22201. For more information about AUSA and the Institute of Land Warfare, visit our website at www.ausa.org. Landpower Essay No. 04-5W September 2004 An Institue of Land Warfare Publication smaller, more modular capabilities. Huba Wass de Czege and Richard Hart Sinnreich describe a multidimensional campaign with a central objective to “transform what otherwise would require a Normandy-style invasion into a strategic meeting engagement.” Deterrence, preclusion, decision and resolution are addressed as simultaneous activities. In part, the logic and vision of modularity flows from this concept.