On War
Clausewitz (1827)
The attention which must be paid to the character of War as it is now made, has a great influence upon all plans, especially on strategic ones.
Since all methods formerly usual were upset by Buonaparte’s luck and boldness, and first-rate Powers almost wiped out at a blow; since the Spaniards by their stubborn resistance have shown what the general arming of a nation and insurgent measures on a great scale can effect, in spite of weakness and porousness of individual parts; since Russia, by the campaign of 1812 has taught us, first, that an Empire of great dimensions is not to be conquered (which might have been easily known before), secondly, that the probability of final success does not in all cases diminish in the same measure as battles, capitals, and provinces are lost (which was formerly an incontrovertible principle with all diplomatists, and therefore made them always ready to enter at once into some bad temporary peace), but that a nation is often strongest in the heart of its country, if the enemy’s offensive power has exhausted itself, and with what enormous force the defensive then springs over to the offensive; further, since Prussia (1813) has shown that sudden efforts may add to an Army sixfold by means of the militia, and that this militia is just as fit for service abroad as in its own country;-- since all these events have shown what an enormous factor the heart and sentiments of a Nation may be in the product of its political and military strength, in fine, since governments have found out all these additional aids, it is not to be expected that they will let them lie idle in future Wars, whether it be that danger threatens their own existence, or that restless ambition drives them on.
That a War which is waged with the whole weight of the national power on each side must be organised differently in principle to those where everything is calculated according to the relations of standing Armies to each other, it is easy to perceive. Standing Armies once resembled fleets, the land force the sea force in their relations to the remainder of the State, and from that the Art of War on shore had in it something of naval tactics, which it has now quite lost.