After all these reflections, we think that although the concentric attack is in itself a means of obtaining greater results, still it should generally only proceed from a previous separation of the parts composing the whole force, and that there are few cases in which we should do right in giving up the shortest and most direct line of operation for the sake of adopting that form.
3. The breadth of a theatre of war can be a motive for attacking on separate lines.
If an army on the offensive in its advance from any point, penetrates with success to some distance into the interior of the enemy’s country, then, certainly, the space which it commands is not restricted exactly to the line of road by which it marches, it will command a margin on each side; still that will depend very much, if we may use the figure, on the solidity and cohesion of the opposing State. If the State only hangs loosely together, if its people are an effeminate race unaccustomed to war, then, without our taking much trouble, a considerable extent of country will open behind our victorious army; but if we have to deal with a brave and loyal population, the space behind our army will form a triangle, more or less acute.
In order to obviate this evil, the attacking force requires to regulate its advance on a certain width of front. If the enemy’s force is concentrated at a particular point, this breadth of front can only be preserved so long as we are not in contact with the enemy, and must be contracted as we approach his position: that is easy to understand.
But if the enemy himself has taken up a position with a certain extent of front, then there is nothing absurd in a corresponding extension on our part. We speak here of one theatre of war, or of several, if they are quite close to each other. Obviously this is, therefore, the case when, according to our view, the chief operation is, at the same time, to be decisive on subordinate points
But now can we always run the chance of this? And may we expose ourselves to the danger which must arise if the influence of the chief operation is not sufficient to decide at the minor points? Does not the want of a certain breadth for a theatre of war deserve special consideration?
Here as well as everywhere else it is impossible to exhaust the number of combinations which may take place; but we maintain that, with few exceptions, the decision on the capital point will carry with it the decision on all minor points. Therefore, the action should be regulated in conformity with this principle, in all cases in which the contrary is not evident.
When Buonaparte invaded Russia, he had good reason to believe that by conquering the main body of the Russian army he would compel their forces on the Upper Dwina to succumb. He left at first only the corps of Oudinot to oppose them, but Wittgenstein assumed the offensive, and Buonaparte was then obliged to send also the sixth corps to that quarter.
On the other hand, at the beginning of the campaign, he directed a part of his forces against Bagration; but that general was carried along by the influence of the backward movement in the centre, and Buonaparte was enabled then to recall that part of his forces. If Wittgenstein had not had to cover the second capital, he would also have followed the retreat of the great army under Barclay.
In the years 1805 and 1809, Buonaparte’s victories at Ulm and Ratisbon decided matters in Italy and also in the Tyrol, although the first was rather a distant theatre, and an independent one in itself. In the year 1806, his victories at Jena and Auerstadt were decisive in respect to everything that might have been attempted against him in Westphalia and Hesse, or on the Frankfort road.