Where the commander divides his plan into parts for separate accomplishment, he will naturally exercise care that each part is, in itself, the suitable basis for a complete and homogeneous plan. Successful execution of all these plans results in the complete accomplishment of his Decision.
Directives required to further the success of a particular operation may be issued without awaiting formulation of the entire plan. Parts of the plan may be transmitted as fragmentary directives to guide the action of subordinates in instantaneous or early execution. Such cases are far more frequent than are those in which a formal written plan, to guide either the operations in their entirety or a part thereof, is prepared and distributed as a directive. Effective action by the subordinate is thus not delayed by the absence of complete written directives.
The commander, more especially during war, may be the only individual who is conversant with the entire plan. He may consider that the necessity for secrecy is paramount, or that there are features to whose details he is unwilling to commit himself until the situation is clearer. However, he may usually expect to disclose its scope and general features to his immediate superior, and the plan in its entirety to his next junior; or, in the interests of mutual understanding, to all his subordinates of the next lower echelon or even to his entire command. The scope of the plan also may be a determining factor. If the plan covers an entire campaign or an extended series of operations, its dissemination is less likely and less general than if it is concerned with only a minor operation.
During peace, in exercises simulating war, the complete plan is frequently given circulation for purposes of training.
Subsidiary Plans. Subsidiary plans, discussed in Chapter VII ([page 168]), are frequently issued as annexes to the Operation Plan ([page 196]) which carries into effect the basic Decision. The commander will be the judge as to whether alternative subsidiary plans are necessary or desirable under the circumstances.
Essentials of Military Directives.
General. By the issue of directives, a commander communicates to his subordinates his plans or such parts of them as he desires. Directives may be oral or written, or may be transmitted by despatch.
Whether a directive is to be effective upon receipt, or under specified conditions, or at a specific time, or upon further instructions from the commander, will be evident from its nature, or will be prescribed in the body of the directive itself.
The manner of determining the details of a plan has been discussed in Chapter VII. The matter contained therein is pertinent to the preparation of a plan that is not to be issued as a directive as well as to one that is to be so issued.
The various categories of directives customarily employed in our naval service, and standard forms for these, are described hereinafter.