The term operational reach, an element of operational design, is new to U.S. Army doctrine. Operational reach is not found in the previous edition of the Army's basic operational doctrine, Field Manual (FM) 100-5, Operations, published in June 1993. However, the term was recently included in the latest edition published in June 2001, now labeled FM 3-0. The term is also new to joint doctrine, first added in the 1995 addition of Joint Publication (JP) 3-0, Doctrine for Joint Operations, under the facets of operational art. Thus, because of the introduction of this new doctrinal term, most Army operational planners may not completely grasp the concept of operational reach and why it is important. Consequently, there is a need to provide a book that fully explains and explores the implications of operational reach. Since doctrine is the source of common understanding, the primary purpose of this study is to determine if current U.S. Army doctrine on operational reach is adequate. In order to accomplish this task, joint doctrine, military theory and history case studies will serve as an analytical framework for examining the concept of operational reach. The research revealed that current Army doctrine on operational reach is inadequate. One of the characteristics of sound doctrine found in TRADOC Regulation 25-36 is "Concise doctrine provides a comprehensive body of thought..." However, the analysis of joint doctrine, military theory, and history provides numerous concepts not included in the Army's current operational manual, FM 3-0. Furthermore, TRADOC Regulation 25-36 also states "Flexible doctrine gives soldiers, leaders, and organizations the leeway to adapt to many different, or changing, circumstances." This passage usually means doctrine should not be overly prescriptive, restricting initiative and innovation. However, to be flexible and adapt to many different, or changing, circumstances, Army planners must have a doctrine that provides more than just a short reference. While doctrine should not have to address every technique, the doctrine on operational reach is clearly lacking the needed breadth to make it adequate. The Army must change doctrine on operational reach. The study discovered that doctrine on operational reach must include the idea of a definitive limit to the decisive employment of military force in every operation. Exceeding this limit will either force an operational pause or lead to culmination. Additionally, the Army must include more concepts on extending operational reach than are currently considered. This will make the doctrine far more comprehensive and flexible.