Military doctrine, in its broad sense, is a digest of the accepted beliefs of the military profession. In a narrower sense a military doctrine may be confined to the views of a single commander on a specific subject. The object of military doctrine, however, is always to furnish a basis for mutual understanding to the end that prompt and harmonious action by subordinate commanders may ensue without the necessity for referring every problem to superior authority before taking action (page 15). Doctrine thus provides a basis for action in possible situations when, for whatever reason, precise instructions have not been issued. The term "doctrine" is inappropriate as a description of the content of orders or instructions prescribing specific methods of action for a particular tactical operation in a situation existent or assumed under circumstances of the moment. The precise instructions thus issued, though they may be the result of doctrine, and may themselves constitute a basis for development of doctrine, are manifestly of the nature of something ordered rather than presented as authoritative opinion. In the broad field of the conduct of war, with its diversified demands, a common viewpoint as to the application of fundamentals is an essential to unity of effort. If the members of the military profession have this common viewpoint, their reasoned beliefs as to the best general methods of waging a particular war may be expected more nearly to approach unanimity. The attainment of unity of effort therefore calls for an understanding of fundamentals (page i), a basic indoctrination which is not only sound but also common to all commanders of the chain of command. Wars come and go. Their effects are painful, but when their wounds are healed mankind is prone to forget and to hope, even to assume, that peace will henceforth be unbroken. Psychological and economic forces then not infrequently impel the State to subordinate the national defense in favor of other interests. During such periods the burdens of command are enlarged. Its responsibility is not lessened, but the means for effective discharge thereof are withheld. The effective conduct of war thus requires that understanding exist (see pages 9 and 10) between the civil representatives of the State and the leaders of the armed forces in the coordination of policy with the preparation and the use of power to enforce it. Of the leaders of the armed forces, as a whole or in combinations, such conduct of war demands the expression of the highest of human qualities, coupled with intimate knowledge of fundamentals, an appreciation of the capacities and limitations of the technique, and the ability to fit the practical details into the general plan in their true relation thereto.