ADVANCE WORK
SUPPLEMENT
CHAPTER I
THE THEORY OF SECURITY
(Copied from the Field Service Regulations)
GENERAL PRINCIPLES
Security embraces all those measures taken by a command to protect itself from observation, annoyance, or surprise by the enemy.
Ordinarily this security is provided in part by cavalry. But as a command is not always preceded by cavalry, and as this cavalry can not always prevent sudden incursions of the enemy or discover his patrols, additional security becomes necessary. This is obtained by covering the immediate front of the command with detachments.
On the march these detachments are called advance, flank, or rear guards; in camp or bivouac they are called outposts.
The object of the former is to facilitate the movement of the main body and to protect it from surprise and observation; the object of the latter is to secure the camp or bivouac against surprise and to prevent an attack upon it before the troops can prepare to resist.