United States military forces are entering the 21st century doctrinally unprepared for the challenges that await. The National Security Strategy of the United States, the National Military Strategy, and Joint Vision 2020 all posit the need for decisive joint action by U. S. military forces in accomplishing 21st century missions. However, on the joint level, Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms, published by the Chairman of the Joint Chiefs of Staff, contains military and associated definitional terms but no definition of the word \"decisive,\" or of the concept of a \"decisive point.\" This is true despite the fact that numerous joint publications other than Joint Vision 2020 refer to the need for decisive action. Military problem-solving analysis based on a methodology of centers of gravity, decisive points, and decisive action are elemental tenants of military thought with foundation in classical strategic and operational theory. Draft versions of doctrinal publications awaiting approval, including Joint Pub 3-0, Doctrine for Joint Operations, and the Army's Field Manual 3-0, Operations, do discuss the concept of \"decisive operations,\" centers of gravity, and decisive points, but they still do not attempt to devise a common sense meaning, or statement, of \"decisive.\" Navy and Air Force foundational doctrinal publications, while making frequent reference to \"decisive\" operations, again do not define \"decisive.\" Air Force and Navy doctrine also does not examine or define a concept of \"decisive points.\" Only the Marine Corps, in Marine Corps Doctrinal Publication 1-3, Tactics, defines \"decisive\" and gives a common sense meaning to the term. This monograph discusses the theoretical and historical foundations for the concept of the \"decisive\" in the works of Clausewitz and Jomini, and demonstrates the importance of a shared doctrinal vision and common understanding of the terms \"decisive,\" \"decisive points,\" and \"centers | Defining Decisive by Charles D Lawhorn, Paperback | Indigo Chapters