Such marches offer, in highland regions, no real danger, since the enemy is unable to throw himself between the columns: it is therefore sufficient that each column be strong enough to defend the valley in which it operates.
Vial: Cours d'art et d'histoire Militaires, vol.
II., p. 82. On this feature of mountain warfare, see also McDougall: Modern Warfare and Modern Artillery, p. 356. But the facility of the tactical defence of highlands renders it necessary for the assailant trear of the enemy, so as to leave him only the alternative of evacuating his position without fighting, or of issuing to attack.
As authority on this same point, see also Dufour, Strategy and Tactics, p. 261; Jomini: Art of War, p. 168; Vial: Cours d'art, etc., vol.
II., p. 83.
I make this exposition of the theory of mountain warfare, because, as will presently appear, the operations of General McClellan in Western Virginia afford a very happy application of all the cardinal principles
ht was turned.
Was this to be considered a great success?
The answer will depend on the line of action marked out for himself by General Lee.
In the defence of rivers, military art presents several distinct lines of conduct.
1. The general on the defensive may permit the crossing of a part of the assailing force, and then, by destroying the means of passage, seek to overwhelm the isolated fraction.
The conduct of the Archduke Charles at Essling, is a good example of this.
See Vial: Cours d'art et d'histoire Militaires, vol.
II., p. 92. 2.
He may oppose directly the passage of the hostile army, or, by occupying advantageous positions, prevent it from deploying.
A striking illustration of this mode of action is presented in the conduct of Vendome in disputing the passage of the Adda by Prince Eugene in 1805.
It is thus described by Dufour: Eugene had gained a march upon Vendome and was attempting to throw a bridge across the Adda at a very favorable spot.