400,000 men, the whole or part of the second line is called up and
formed into auxiliary regiments, brigades and divisions, and in case of
necessity the third line is also called upon, though usually this is
only in the last resort and for home defence only. The proportion of
reservists to men with the colours varies of course with the length of
service. Thus in France or Germany, with two years' service in force,
half of the rank and file of a unit in war would be men recalled from
civil life. The true military value of reservists is often questioned,
and under certain circumstances it is probable that units would take the
field at peace strength without waiting for their reservists. The
frontier guards of the continental military powers, which are expected
to move at the earliest possible moment after hostilities have begun,
are maintained at a higher effective than other units, and do not depend
to any great extent on receiving reservists. The peace footing of
cavalry and artillery units is similarly maintained at an artificial
level. An operation of the nature of a _coup de main_ would in any case
be carried out by the troops available at the moment, however large
might be the force required--twenty weak battalions would, in fact, be
employed instead of ten strong ones. There is another class of troops,
which may be called depot troops. These consist of officers and men left
behind when the active corps completed with reserves takes the field,
and they have (a) to furnish drafts for the front--and (b) to form a
nucleus upon which all later formations are built up. The troops of the
second line undertake minor work, such as guarding railways, and also
furnish drafts for the field army. Later, when they have been for some
time under arms, the second line troops are often employed by themselves
in first line. A year's training under war conditions should bring such
troops to the highest efficiency. As for irregulars, they have real
military value only when the various permanent establishments do not
take up the whole fighting strength of the nation, and thus states
having universal service armies do not, as a rule, contemplate the
employment of combatants other than those shown on the peace rolls. The
status of irregulars is ill defined, but it is practically agreed that
combatants, over whose conduct the military authorities have no
disciplinary power, should be denied the privileges of recognized
soldiers, and put to death if captured. So drastic a procedure is
naturally open to abuse and is not always expedient. Still, it is
perfectly right that the same man shall not be allowed, for example, to
shoot a sentry at one moment, and to claim the privileges of a harmless
civilian at the next. The division into first, second and third lines
follows generally from the above. The first line troops, in a conscript
army, are the "active army" or regulars, permanently under arms in peace
time, and its reserves, which are used on the outbreak of war to
complete the existing units to full strength. The German terms
_Landwehr_ and _Landsturm_ are often applied to armies of the second and
the third lines.