On War

by Carl von Clausewitz

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.

If circumstances are less favourable, if the population is not so great, or if it consists more of artisans than agriculturists, if the soil is bad, the country already several times overrun—then of course the results will fall short of what we have supposed. Still, we must remember that if the breadth of the front of a column is extended from two miles to three, we get a superficial extent of country more than double in size, that is, instead of four we command nine square miles, and that this is still an extent which in ordinary cases will always admit of concentration for action; we see therefore that even under unfavourable circumstances this method of subsistence will still be always compatible with a continuous march.

But if a halt of several days takes place, then great distress must ensue if preparations have not been made beforehand for such an event in other ways. Now these preparatory measures are of two kinds, and without them a considerable army even now cannot exist. The first is equipping the troops with a wagon train, by means of which bread or flour, as the most essential part of their subsistence, can be carried with them for a few, that is, for three or four days; if to this we add three or four days’ rations which the soldier himself can carry, then we have provided what is most indispensable in the way of subsistence for eight days.

The second arrangement is that of a regular commissariat, which whenever there is a moment’s halt gathers provisions from distant localities, so that at any moment we can pass over from the system of quartering on the inhabitants to a different system.

Subsisting in cantonments has the immense advantage that hardly any transport is required, and that it is done in the shortest time, but certainly it supposes as a prior condition that cantonments can be provided for all the troops.