As we shall have hereafter to return to this subject when treating of the plan of a war, we shall only at present add that, when such a lateral position is taken, the capital or place which it is the object to protect, must, in every case, be capable of making some resistance that it may not be occupied and laid under contribution by every flying column or irregular band.
But we have still to consider another peculiarity in the direction of such a line of retreat, that is, a sudden change of direction. After the Russians had kept the same direction as far as Moscow they left that direction which would have taken them to Wladimir, and after first taking the road to Riazan for some distance, they then transferred their army to the Kaluga road. If they had been obliged to continue their retreat they could easily have done so in this new direction which would have led them to Kiew, therefore much nearer again to the enemy’s frontier. That the French, even if they had still preserved a large numerical superiority over the Russians, could not have maintained their line of communication by Moscow under such circumstances is clear in itself; they must have given up not only Moscow but, in all probability, Smolensk also, therefore have again abandoned the conquests obtained with so much toil, and contented themselves with a theatre of war on this side the Beresina.
Now, certainly, the Russian army would thus have got into the same difficulty to which it would have exposed itself by taking the direction of Kiew at first, namely, that of being separated from the mass of its own territory; but this disadvantage would now have become almost insignificant, for how different would have been the condition of the French army if it had marched straight upon Kiew without making the detour by Moscow.
It is evident that such a sudden change of direction of a line of retreat, which is very practicable in a spacious country, ensures remarkable advantages.