In its front it breaks up roads or breaks down bridges; while it erects or repairs those in its rear: it forms abbatis, raises batteries, fortifies passes, or intrenches encampments; and to the system of deprivation adds all the activity, stratagem, and boldness of _la petite guerre_.

Dividing itself into detachments, it multiplies its own attacks and the alarms of the enemy.

Collecting itself at a single point, it obstructs his progress for days, and sometimes for weeks together.

Does it even abandon the avenues it is destined to defend?
It is but for the purpose of shielding them more securely, by the attack of his hospitals, magazines, convoys, or reinforcements.

In a word, by adopting the maxim, that the _enemy must be made to pay for whatever he gains_, it disputes with him every inch of ground, and if at last it yields to him a victory, it is of that kind which calls forth only his sighs." In discussing the subject of strategy, certain technical terms are employed, such as _theatre of war; theatre of operations; base of operations_, or the line from which operations start; _objective points_, or points to which the operations are directed; _line of operations_, or the line along which an army moves; _key points_, or points which it is important for the defensive army to secure; _line of defence,_ or the line which it is important to defend at all hazards: and in general, _strategic points, strategic lines, strategic positions, &c._ As these terms are very generally used in military books, it may be well to make ourselves thoroughly acquainted with their import.