3. To observe and hold in position a large portion of the opposing
army, while a blow is struck at the remainder.

4. To carry off a considerable convoy of provisions or munitions,
on receiving which depended the continuance of a siege or the
success of any strategic enterprise, or to protect the march of a
convoy of your own.

5. To make a demonstration to draw the enemy in a direction where
you wish him to go, in order to facilitate the execution of an
enterprise in another direction.

6. To mask, or even to invest, one or more fortified places for a
certain time, with a view either to attack or to keep the garrison
shut up within the ramparts.

7. To take possession of an important point upon the communications
of an enemy already retreating.

However great may be the temptation to undertake such operations as
those enumerated, it must be constantly borne in mind that they are
always secondary in importance, and that the essential thing is to be
successful at the decisive points. A multiplication of detachments must,
therefore, be avoided. Armies have been destroyed for no other reason
than that they were not kept together.

We will here refer to several of these enterprises, to show that their
success depends sometimes upon good fortune and sometimes upon the skill
of their designer, and that they often fail from faulty execution.