When General Bulow marched into Holland in 1814, it was to be foreseen that the thirty thousand men composing his corps would not only neutralise the same number of Frenchmen, but would, besides, give the English and the Dutch an opportunity of entering the field with forces which otherwise would never have been brought into activity.
Thus, therefore, the first consideration in the combination of a plan for a war, is to determine the centres of gravity of the enemy’s power, and, if possible, to reduce them to one. The second is to unite the forces which are to be employed against the centre of force into one great action.
Here now the following grounds for dividing our forces may present themselves:
- The original position of the military forces, therefore also the situation of the States engaged in the offensive.
If the concentration of the forces would occasion detours and loss of time, and the danger of advancing by separate lines is not too great, then the same may be justifiable on those grounds; for to effect an unnecessary concentration of forces, with great loss of time, by which the freshness and rapidity of the first blow is diminished, would be contrary to the second leading principle we have laid down. In all cases in which there is a hope of surprising the enemy in some measure, this deserves particular attention.
But the case becomes still more important if the attack is undertaken by allied States which are not situated on a line directed towards the State attacked not one behind the other but situated side by side. If Prussia and Austria undertook a war against France, it would be a very erroneous measure, a squandering of time and force if the armies of the two powers were obliged to set out from the same point, as the natural line for an army operating from Prussia against the heart of France is from the Lower Rhine, and that of the Austrians is from the Upper Rhine.