A third disputed point is his belief in the superior tactical efficiency, under favourable circumstances, of the Napoleonic method of breaking the enemy's line in the centre. Breaking the line by a frontal attack was, of course, much easier in Clausewitz's Napoleonic day than it is with the long-ranging arms of our day, and it is only natural that Clausewitz in his writings should give it the full tactical importance which it then deserved. His book would not be true to the tactical conditions of his day had he not done so, with Rivoli, Austerlitz, Salamanca, Eckmuhl, etc., before his mind. But it seems hardly correct to accuse him of over-partiality to frontal attacks, for he has examined both frontal and enveloping attacks most fairly, giving to each their relative advantages and disadvantages, and concluding: "The envelopment may lead directly to the _destruction_ of the enemy's army, if it is made with very superior numbers and succeeds. If it leads to victory the early results are _in every case_ greater than by breaking the enemy's line. Breaking the enemy's line can only lead indirectly to the destruction of the enemy's army, and its effects are hardly shown so much on the first day, but rather strategically afterwards,"[71] by forcing apart on different lines of retreat the separated fragments of the beaten army. "The breaking through the hostile army by massing our principal force against one point, _supposes an excessive length of front on the part of the enemy_; for in this form of attack the difficulty of occupying the remainder of the enemy's force with few troops is greater, because the enemy's forces nearer to the principal point of attack can easily join in opposing it. Now in an attack upon the centre there are such forces on both sides of the attack; in an attack upon a flank, only on one side. The consequence of this is that such a central attack may easily end in a very disadvantageous form of combat, _through a convergent counter-attack_." Which is exactly our modern difficulty. "The choice between these two forms of attack must therefore be made according to the existing conditions of the moment. Length of front, the nature and direction of the line of retreat, the military qualities of the enemy's troops, and the characteristics of their general, lastly the ground must determine the choice." Speaking generally he regards the _concentric_ enveloping form of tactical attack aiming at the enemy's line of retreat as the most efficacious and natural. "On the field of battle itself ... the enveloping form must always be considered the most effectual."[72] And the _eccentric_ or frontal counter-attack at the extended enveloping attack as the most efficacious and natural form of the defence, such as Napoleon's counter-attacks at Austerlitz or Dresden, or Wellington's at Salamanca. "And we think that one means is at least as good as the other."[73] * * * * *