This paper looks at how the U. S. military needs to change its perspectives on high-intensity/high-end warfighting commonly referred to as major theater war (MTW). It focuses on that part of the military operational spectrum where significant conventional forces are committed in violent warfare--such as large, force on force conventional confrontations. Yet since the Gulf War, history continues to repeatedly demonstrate that the conduct of modern conventional warfare is not solely constrained to classic, canonical MTW constructs alone. In fact, future MTWs may not be confined to a Southwest Asia (Iraq) or Northeast Asia (North Korea) scenario. To understand how to fight and win future wars, this work first reviews the current MTW paradigm, with respect to the history of warfare, current warplans, and joint doctrine. It then summarizes and compares future Joint and Service Visions, in an attempt to gain insight on where the military views its future path. Given that foundation, a new definition for major theater war is proposed, along with an analysis of significant influences on its future character--specifically coalitions and alliances, access, and American casualty tolerance. Using the new, broader definition for an MTW, the work frames three possible MTW archetypal scenarios for consideration. Finally, it concludes with outlining concepts and critical enabling capabilities to fight and win the future high-intensity/high-end warfight. It is hoped this work serves as a source for the Joint Staff, Warfighting CINCs, Services, and new Administration in their efforts during the upcoming Quadrennial Defense Review--which is aimed at determining how the United States should structure its military forces for the future.