On War

by Carl von Clausewitz

One of the most brilliant surprises in history, is that made by the Duke of Lorraine in 1643, on the cantonments of the French, under General Ranzan, at Duttlingen. The corps was 16,000 men, and they lost the General commanding, and 7,000 men; it was a complete defeat. The want of outposts was the cause of the disaster.

The surprise of Turenne at Mergentheim (Mariendal, as the French call it,) in 1644, is in like manner to be regarded as equal to a defeat in its effects, for he lost 3,000 men out of 8,000, which was principally owing to his having been led into making an untimely stand after he got his men assembled. Such results we cannot, therefore, often reckon upon; it was rather the result of an ill-judged action than of the surprise, properly speaking, for Turenne might easily have avoided the action, and have rallied his troops upon those in more distant quarters.

A third noted surprise is that which Turenne made on the Allies under the great Elector, the Imperial General Bournonville and the Duke of Lorraine, in Alsace, in the year 1674. The trophies were very small, the loss of the Allies did not exceed 2,000 or 3,000 men, which could not decide the fate of a force of 50,000; but the Allies considered that they could not venture to make any further resistance in Alsace, and retired across the Rhine again. This strategic result was all that Turenne wanted, but we must not look for the causes of it entirely in the surprise. Turenne surprised the plans of his opponents more than the troops themselves; the want of unanimity amongst the allied generals and the proximity of the Rhine did the rest. This event altogether deserves a closer examination, as it is generally viewed in a wrong light.

In 1741, Neipperg surprised Frederick the Great in his quarters; the whole of the result was that the king was obliged to fight the battle of Mollwitz before he had collected all his forces, and with a change of front.

In 1745, Frederick the Great surprised the Duke of Lorraine in his cantonments in Lusatia; the chief success was through the real surprise of one of the most important quarters, that of Hennersdorf, by which the Austrians suffered a loss of 2,000 men; the general result was that the Duke of Lorraine retreated to Bohemia by Upper Lusatia, but that did not at all prevent his returning into Saxony by the left bank of the Elbe, so that without the battle of Kesselsdorf, there would have been no important result.

1758. The Duke Ferdinand surprised the French quarters; the immediate result was that the French lost some thousands of men, and were obliged to take up a position behind the Aller. The moral effect may have been of more importance, and may have had some influence on the subsequent evacuation of Westphalia.

If from these different examples we seek for a conclusion as to the efficacy of this kind of attack, then only the two first can be put in comparison with a battle gained. But the corps were only small, and the want of outposts in the system of war in those days was a circumstance greatly in favour of these enterprises. Although the four other cases must be reckoned completely successful enterprises, it is plain that not one of them is to be compared with a battle gained as respects its result. The general result could not have taken place in any of them except with an adversary weak in will and character, and therefore it did not take place at all in the case of 1741.

In 1806 the Prussian army contemplated surprising the French in this manner in Franconia. The case promised well for a satisfactory result. Buonaparte was not present, the French corps were in widely extended cantonments; under these circumstances, the Prussian army, acting with great resolution and activity, might very well reckon on driving the French back across the Rhine, with more or less loss. But this was also all; if they reckoned upon more, for instance, on following up their advantages beyond the Rhine, or on gaining such a moral ascendancy, that the French would not again venture to appear on the right bank of the river in the same campaign, such an expectation had no sufficient grounds whatever.

In the beginning of August, 1812, the Russians from Smolensk meditated falling upon the cantonments of the French when Napoleon halted his army in the neighbourhood of Witepsk. But they wanted courage to carry out the enterprise; and it was fortunate for them they did; for as the French commander with his centre was not only more than twice the strength of their centre, but also in himself the most resolute commander that ever lived, as further, the loss of a few miles of ground would have decided nothing, and there was no natural obstacle in any feature of the country near enough up to which they might pursue their success, and by that means, in some measure make it certain, and lastly, as the war of the year 1812 was not in any way a campaign of that kind, which draws itself in a languid way to a conclusion, but the serious plan of an assailant who had made up his mind to conquer his opponent completely,—therefore the trifling results to be expected from a surprise of the enemy in his quarters, appear nothing else than utterly disproportionate to the solution of the problem, they could not justify a hope of making good by their means the great inequality of forces and other relations. But this scheme serves to show how a confused idea of the effect of this means may lead to an entirely false application of the same.

What has been hitherto said, places the subject in the light of a strategic means. But it lies in its nature that its execution also is not purely tactical, but in part belongs again to strategy so far, particularly that such an attack is generally made on a front of considerable width, and the army which carries it out can, and generally will, come to blows before it is concentrated, so that the whole is an agglomeration of partial combats. We must now add a few words on the most natural organisation of such an attack.