On War

by Carl von Clausewitz

The feeding of horses by an artificial system of supply is, however, an experiment which has not been tried, because forage is much more difficult to provide on account of its bulk. A ration for a horse weighs about ten times as much as one for a man, and the number of horses with an army is more than one-tenth the number of men, at present it is one-fourth to one-third, and formerly it was one-third to one-half, therefore the weight of the forage required is three, four, or five times as much as that of the soldier’s rations required for the same period of time; on this account the shortest and most direct means were taken to meet the wants of an army in this respect, that is by foraging expeditions. Now these expeditions occasioned great inconvenience in the conduct of war in other ways, first by making it a principal object to keep the war in the enemy’s country; and next because they made it impossible to remain very long in one part of the country. However, at the time of the Silesian war, foraging expeditions were much less frequent, they were found to occasion a much greater drain upon the country, and much greater waste than if the requirements were satisfied by means of requisitions and imposts.

When the French Revolution suddenly brought again upon the war stage a national army, the means which governments could command were found insufficient, and the whole system of war, which had its origin in the limited extent of these means, and found again its security in this limitation, fell to pieces, and of course in the downfall of the whole was included that of the branch of which we are now speaking, the system of subsistence. Without troubling themselves about magazines, and still less about such an organisation as the artificial clockwork of which we have spoken, by which the different divisions of the transport service went round like a wheel, the leading spirits of the revolution sent their soldiers into the field, forced their generals to fight, subsisted, reinforced their armies, and kept alive the war by a system of exaction, and of helping themselves to all they required by robbery and plunder.

Between these two extremes the war under Buonaparte, and against him, preserved a sort of medium, that is to say, it just made use of such means as suited it best amongst all that were available; and so it will be also in future.

The modern method of subsisting troops, that is, seizing every thing which is to be found in the country without regard to meum et tuum may be carried out in four different ways: that is, subsisting on the inhabitant, contributions which the troops themselves look after, general contributions and magazines. All four are generally applied together, one generally prevailing more than the others: still it sometimes happens that only one is applied entirely by itself.

1.—Living on the inhabitants, or on the community, which is the same thing.

If we bear in mind that in a community consisting even as it does in great towns, of consumers only, there must always be provisions enough to last for several days, we may easily see that the most densely populated place can furnish food and quarters for a day for about as many troops as there are inhabitants, and for a less number of troops for several days without the necessity of any particular previous preparation. In towns of considerable size this gives a very satisfactory result, because it enables us to subsist a large force at one point. But in smaller towns, or even in villages, the supply would be far from sufficient; for a population of 3,000 or 4,000 in a square mile which would be large in such a space, would only suffice to feed 3,000 or 4,000 soldiers, and if the whole mass of troops is great they would have to be spread over such an extent of country at this rate as would hardly be consistent with other essential points. But in level countries, and even in small towns, the quantity of those kinds of provisions which are essential in war is generally much greater; the supply of bread which a peasant has is generally adequate to the consumption of his family for several, perhaps from eight to fourteen days; meat can be obtained daily, vegetable productions are generally forthcoming in sufficient quantity to last till the following crop. Therefore in quarters which have never been occupied there is no difficulty in subsisting troops three or four times the number of the inhabitants for several days, which again is a very satisfactory result. According to this, where the population is about 2,000 or 3,000 per square mile, and if no large town is included, a column of 30,000 would require about four square miles, which would be a length of side of two miles. Therefore for an army of 90,000, which we may reckon at about 75,000 combatants, if marching in three columns contiguous to each other, we should require to take up a front six miles in breadth in case three roads could be found within that breadth.

If several columns follow one another into these cantonments, then special measures must be adopted by the civil authorities, and in that way there can be no great difficulty in obtaining all that is required for a day or two more. Therefore if the above 90,000 are followed the day after by a like number, even these last would suffer no want; this makes up the large number of 150,000 combatants.

Forage for the horses occasions still less difficulty, as it neither requires grinding nor baking, and as there must be forage forthcoming in sufficient quantity to last the horses in the country until next harvest, therefore even where there is little stall-feeding, still there should be no want, only the deliveries of forage should certainly be demanded from the community at large, not from the inhabitants individually. Besides, it is supposed that some attention is, of course, paid to the nature of the country in making arrangements for a march, so as not to send cavalry mostly into places of commerce and manufactures, and into districts where there is no forage.

The conclusion to be drawn from this hasty glance is, therefore, that in a moderately populated country, that is, a country of from 2,000 to 3,000 souls per square mile, an army of 150,000 combatants may be subsisted by the inhabitants and community for one or two days within such a narrow space as will not interfere with its concentration for battle, that is, therefore, that such an army can be subsisted on a continuous march without magazines or other preparation.

On this result were based the enterprises of the French army in the revolutionary war, and under Buonaparte. They marched from the Adige to the Lower Danube, and from the Rhine to the Vistula, with little means of subsistence except upon the inhabitants, and without ever suffering want. As their undertakings depended on moral and physical superiority, as they were attended with certain results, and were never delayed by indecision or caution, therefore their progress in the career of victory was generally that of an uninterrupted march.