We see, therefore, that however passive this defence is in the leading ideas on which it is based, still it must comprise many active means, and in its organisation may be forearmed in many ways against complicated events. Usually those defences pass for the best which make the most use of active or even offensive means; but this depends in great part on the nature of the country, the characteristics of the troops, and even on the talent of the general; partly we are also very prone in general to expect too much from movement, and other auxiliary measures of an active nature, and to place too little reliance on the local defence of a formidable natural obstacle. We think we have thus sufficiently explained what we understand by an extended line of defence, and we now turn to the third auxiliary means, the placing ourselves in front of the enemy by a rapid march to a flank.
This means is necessarily one of those provided for that defence of a country which we are now considering. In the first place the defender, even with the most extended position, often cannot guard all the approaches to his country which are menaced; next, in many cases, he must be ready to repair with the bulk of his forces to any posts upon which the bulk of the enemy’s force is about to be thrown, as otherwise those posts would be too easily overpowered; lastly, a general who has an aversion to confining his army to a passive resistance in an extended position, must seek to attain his object, the protection of the country, by rapid, well-planned, and well-conducted movements. The greater the spaces which he leaves exposed, the greater the talent required in planning the movements, in order to arrive anywhere at the right moment of time.