lacking
in morale, a thinner deployment is permissible. (436)

=451. Density of whole deployment varies with size of command.= The
density of the whole deployment increases with the size of the
command, because the larger the command the greater the necessity for
reserves. Thus, battalion acting alone may attack two men per yard of
front, but a regiment, with three battalions, may only double the
front of the one battalion. (437)

=452. Division of battle line into battle districts and density of
deployment therein.= By the assignment of divisions or larger units to
parts of a line of battle several miles long, a series of
semi-independent battle, or local combat, districts are created.

The general deployment for a long line of battle comprising several
battle districts is not directly considered in these regulations. The
deployments treated of herein are those of the infantry within such
districts.

The density of deployment in these districts may vary greatly,
depending upon the activity expected in each. Within these battle
districts, as well as in smaller forces acting alone, parts of the
line temporarily of less importance may be held weakly, in order to
economize troops and to have more at the decisive point. (438)

=453. Extent of front occupied by a unit depends upon security of
flanks.= The front that a unit may occupy when deployed depends also
upon whether its flanks are secured. If both flanks are secured by
other troops, the unit may increase its front materially by reducing
its reserve or supports. If only one flank is so secured, the front
may still be somewhat increased, but the exposed flank must be guarded
by posting the supports or reserve toward that flank.

Natural obstacles that secure the flanks have practically the same
effect upon deployment. (439)

=454. Regiments, battalions, and companies deployed side by side.=
Except when assigned as supports or reserve, regiments in the brigade,
battalions in the regiment, and companies in the battalion are, when
practicable, deployed side by side. (440)

=455. Battalions furnish firing line and supports; larger units
furnish reserves; employment of reserve.= In the deployment,
battalions establish the firing line, each furnishing its own support.

In each unit larger than the battalion a reserve is held out, its
strength depending upon circumstances. In general, the reserve is
employed by the commander to meet or improve conditions brought ab