Survey of Factors of Fighting Strength. The feasibility and acceptability of action for the attainment of an objective are dependent (see the Fundamental Military Principle--page 41) on the factors of fighting strength. Fighting strength (page 35) is derived from the means available and opposed, as influenced by the characteristics of the theater of operations. A survey of these factors, in proper detail according to the nature of the problem, is therefore a necessary phase in the process of its solution. Such a survey completes the basis for the study of courses of action. Courses of Action. The estimate process naturally takes account (page 80) of methods for attaining the objective indicated in the assigned task. The military profession has, from time to time, applied a variety of terms to designate such methods. Terms so used include, among others, "plans open to us" (or "to the enemy"), "lines of action", and "courses of action". The last-noted, having been standard in our naval service for many years, is the term used in this discussion. Each course of action is thus a plan of military operations for the attainment of the assigned objective, and each thus indicates (page 37) "an act or a series of acts" which may be undertaken to that end. Until a final selection is made for embodiment in the Decision, each course of action is a tentative solution of the problem. For the reason given below, a course of action, while under consideration as a tentative solution of the problem, is also correctly conceived as indicating an objective and, in proper detail, the action for its attainment. When embodied in the Decision, the adopted course of action or combination of courses becomes the commander's general plan (or the basis thereof) for the employment of his force; such a general plan will naturally indicate the commander's general objective (page 49) and, in proper detail, the action to be taken for its attainment (page 44). The objective may be specifically stated or may be inferred (see page 82; also page 84 for the corresponding discussion of the expression of tasks); but, in any event, clear thinking demands that the objective be definitely envisaged. There is a manifest advantage in such definite envisaging of the objectives involved in courses of action. Suitability as to the appropriate effect desired--the first requirement in the selection of a correct objective (page 51)--is much more readily tested on this basis. The practical bearing of this fact becomes apparent during the early stages (Chapter VI) of the process of solving military problems. Frequent examples of naval courses of action include (see page 92): (1) "To destroy the enemy force." Here the objective, "destruction of the enemy force", is specifically indicated. (2) "To divert the enemy force." Here also the objective, in this case "diversion of the enemy force", is specifically indicated.