use of this force the major can exert an
influence not otherwise possible over his firing line and can control,
within reasonable limits, an action once begun. So if his battalion be
assigned to the _firing line_ the major will cause one, two, or three
companies to be deployed on the firing line, retaining the remaining
companies or company as a _support_ for that firing line. The division
of the battalion into firing line and support will depend upon the
front to be covered and the nature and anticipated severity of the
action.

299. If the battalion be part of a larger command, the number of
companies in the firing line will generally be determinable from the
regimental commander's order; the remainder constitutes the support.
If the battalion is acting alone, the support must be strong enough to
maintain the original fire power of the firing line, to protect the
flanks, and to perform the functions of a reserve, whatever be the
issue of the action. See paragraph 346.

300. If the battalion is operating alone, the support may, according
to circumstances, be held in one or two bodies and placed behind the
center, or one or both flanks of the firing line, or echeloned beyond
a flank. If the battalion is part of a larger force, the support is
generally held in one body.

301. The distance between the firing line and the supporting group or
groups will vary between wide limits; it should be as short as the
necessity for protection from heavy losses will permit. When cover is
available, the support should be as close as 50 to 100 yards; when
such cover is not available, it should not be closer than 300 yards.
It may be as far as 500 yards in rear if good cover is there
obtainable and is not obtainable at a lesser distance.

302. In exceptional cases, as in a meeting engagement, it may be
necessary to place an entire battalion or regiment in the firing line
at the initial deployment, the support being furnished by other
troops. Such deployment causes the early mingling of the larger units,
thus rendering leadership and control extremely difficult. The
necessity for such deployment will increase with the inefficiency of
the commander and of the service of information.

_Fire._

303. Fire direction and fire control are functions of company and
platoon commanders. The major makes the primary apportionment of the
target--in defense, by assigning sectors of fire; in attack, by
assigning the objective. In the latter ca