"This monograph examines military doctrine and explains why understanding its evolution and the influences that shape it are of vital importance to military practitioners, strategists, and statesmen alike. Doctrine, defined herein as the expression of a military's institutional 'belief system,' constitutes a significant yet hitherto unrecognized means by which this belief system can be understood and evaluated. This understanding and evaluation is in turn important because it is this belief system that determines the way a military fights, the relationship it will have with the state and society that sustain it, and its institutional culture. To get the belief system right means good strategy, victory, stable civil-military relations, and organizational wellbeing. Getting it wrong means sub-optimal strategy and operational outcomes or even defeat, strained civil-military relationships, and organizational dysfunction. This is why it is vital that military practitioners, strategists, and statesmen all have a well-developed understanding of this belief system and its implications. Yet currently, many do so only subconsciously, if at all. The aim of this monograph is to help make this understanding explicit. The potentially detrimental results of many military practitioners, strategists, and statesmen having developed only an implicit understanding of the military belief system can be seen in the state of conceptual confusion that has reigned since the end of the Cold War. Today, Western militaries are awash with competing and contrasting terms, ideas, and concepts. As Colin S. Gray recently observed, 'Americans in the2000s went to war and by and large have remained conceptually wounded.' Brian McAllister Linn traced the roots of this problem even further back asserting that 'even before the [Global War on Terror] the defense community was in the midst of a vibrant debate over whed1er the nature of war itself had changed .'"