ront of the
army the _tete de pont_ of Praga and Warsaw; so that his communications
were safe, while Benningsen, forced to face him and to make his line
parallel to the Baltic, might be cut off from his base, and be thrown
back upon the mouths of the Vistula. Napoleon executed another very
remarkable change of strategic front in his march from Gera upon Jena
and Naumburg in 1806. Moreau made another in moving by his right upon
Augsburg and Dillingen, fronting the Danube and France, and thereby
forcing Kray to evacuate the intrenched camp at Ulm.

The change of the strategic front to a position perpendicular to the
base may be a temporary movement for an operation of a few days'
duration, or it may be for an indefinite time, in order to profit by
important advantages afforded by certain localities, to strike decisive
blows, or to procure for the army a good line of defense and good
pivots of operations, which would be almost equivalent to a real base.

It often happens that an army is compelled to have a double strategic
front, either by the features of the theater of war, or because every
line of offensive operations requires protection on its flanks. As an
example of the first, the frontiers of Turkey and Spain may be cited. In
order to cross the Balkan or the Ebro, an army would be obliged to
present a double front,--in the first case, to face the valley of the
Danube; in the second, to confront forces coming from Saragossa or Leon.

All extensive countries necessitate, to a greater or less degree, the
same precaution. A French army in the valley of the Danube will require
a double front as soon as the Austrians have thrown sufficient troops
into the Tyrol or Bohemia to give rise to any anxiety. Those countries
which present a narrow frontier to the enemy are the only exception,
since the troops left on the frontier to harass the flanks of the enemy
could themselves be cut off and captured. This necessity of double
strategic fronts is one of the most serious inconveniences of an
offensive war, since it requires large detachments, which are always
dangerous. (See Article XXXVI.)

Of course, all that precedes relates to regular warfare. In a national
or intestine war the whole country is the scene of hostilities.
Nevertheless, each large fraction of an army having a defined aim would
have its own strategic front determined by the features of the country
and the positions occupied by the large bodies of the enemy. Thu