that province, because it lies nearer to Silesia than to the Mark, and at the same time covers the latter.
Even in 1740 and 1741, after Frederick the Great had once conquered Silesia, it did not weaken his army in the field, because, owing to its form and situation as well as the contour of its frontier line, it only presented a narrow point to the Austrians, as long as they were not masters of Saxony, and besides that, this small point of contact also lay in the direction of the chief operations of the contending forces.
If, on the other hand, the conquered territory is a strip running up between hostile provinces, has an eccentric position and unfavourable configuration of ground, then the weakening increases so visibly that a victorious battle becomes not only much easier for the enemy, but it may even become unnecessary as well.
The Austrians have always been obliged to evacuate Provence without a battle when they have made attempts on it from Italy. In the year 1744 the French were very well pleased even to get out of Bohemia without having lost a battle. In 1758 Frederick the Great could not hold his position in Bohemia and Moravia with the same force with which he had obtained such brilliant successes in Silesia and Saxony in 1757. Examples of armies not being able to keep possession of conquered territory solely because their combatant force was so much weakened thereby, are so common that it does not appear necessary to quote any more of them.
Therefore, the question whether we should aim at such an object depends on whether we can expect to hold possession of the conquest or whether a temporary occupation (invasion, diversion) would repay the expenditure of force required: especially, whether we have not to apprehend such a vigorous counterstroke as will completely destroy the balance of forces. In the chapter on the culmination point we have treated of the consideration due to this question in each particular case.
There is just one point which we have still to add.