An “operation” is any considerable strategical undertaking.

A “theatre of operations” is usually defined as embracing all the territory we seek to take possession of or to defend.

A truer definition is:  “The area, whether of sea or land or both, within which the enemy must be overpowered before we can secure the object of the particular operation.”

Consequently, since the nature of the war varies with the object, it may be defensive in one theatre of operations and offensive in another.

Where the operations are defensive in character any special movement or movements may be offensive.

As the plan of war determines the theatres of operation in the theatre of war, so in each theatre of operation it determines the lines of operation and the objectives.

Objective

An objective is “any point or force against which an offensive movement is directed.”  Thus, where the object in any theatre of operation is to get command of a certain sea in which the enemy maintains a fleet, that fleet will usually be the objective.

“Objective” in ordinary use is frequently confused with “object.”  For purposes of strategical discussion it is desirable to keep them sharply distinguished. Objective is the end of some particular movement or operation, and is the special concern of the officer in command. Object is the end of a system of operations and is the special concern of the general staff or director of the war.  An objective is some definite point which we wish to get from the enemy or prevent his occupying, or some part of his strength which we wish to destroy.  It is incorrect to use the term of anything we already possess.  Thus, Vladivostock is often said to have been Rojesvensky’s objective.  It was, strictly speaking, only his destination.  To reach it and concentrate with the units already there was the primary object of the operations entrusted to him.  He had no true objective before him except Togo’s fleet.

An objective is always subordinate to some object.  It is a step to the attainment of that object.

Lines of Operation

A line of operation is “the area of land or sea through which we operate from our base or starting point to reach our objectives.”

Lines of operation may be exterior or interior.  We are said to hold the interior lines when we hold such a position, in regard to a theatre of operations, that we can reach its chief objective points, or forces, more quickly than the enemy can move to their defence or assistance.  Such a position is called an interior position.  “Exterior Lines” and “Exterior Positions” are the converse of these.

Lines of Communication

This expression is used of three different things:—­

    (1) Lines of supply, running from the base of operations to the point
    which the operating force has reached.