克劳塞维茨论有限战争与无限战争

井冈山卫士

Clausewitz began by making two points about the defence. First, although its object was negative, it was a stronger form of war than the attack. It was easier to hold ground than to take it, to preserve than to acquire. A weaker force, unless it was desperate, did not attack a stronger one; it stayed on the defensive and made up for its weakness by maximizing the advantages of a defensive position. Beati sunt possidentes, said Clausewitz: blessed are those in possession, in war as in law.

But defence could not be purely passive. Clausewitz’s second point was that defence essentially consisted of two phases: waiting for a blow and parrying it (Abwehr). This latter action, this counterblow against the attacker, was intrinsic to the whole concept of defence. An army took up defensive positions in order to fight from them. It selected them in order to maximize its fighting effectiveness, not least that of its fire power. A defence was a shield, said Clausewitz, but an active shield, one ‘made up of well-directed blows’ (p. 357). You did not just sit behind your defences and let the attack overwhelm you: you fired back. It was usually the defender, indeed, who fired the first shot in any war. As Clausewitz put it, in a passage which gained the sardonic approval of Lenin:

The aggressor is always peace-loving (as Bonaparte always claimed to be); he would prefer to take over our country unopposed. To prevent his doing so one must be willing to make war and be prepared for it. In other words it is the weak, those most likely to need defence, who should always be armed in order not to be overwhelmed. (p. 370)

A defensive strategy consisted in finding the right balance between these two elements, waiting and parrying; of choosing the right time and place to unleash that ‘flashing sword of vengeance’ which Clausewitz described as ‘the greatest moment for the defender’. There was a whole range of possibilities open, from an immediate counter- attack the moment the enemy crossed the frontier – minimum waiting, immediate riposte – to a long withdrawal into the interior of the country such as the Russians had carried out in 1812 and were to do again in 1941 and 1942, delaying until the last possible moment before launching their counter-attack. All depended, said Clausewitz, whether one wanted primarily to destroy the enemy by one’s own forces, or by ‘his own exertions’ (p. 384).

井冈山卫士

Human nature being what it is, went on Clausewitz, this was the case more often than not. Information about the enemy was uncertain, and one was always more likely to overestimate than to underestimate the opponent’s strength. ‘The fear and indecision native to the human mind’ thus weighed everyone down, constituting a kind of ‘moral force of gravity . . . In the fiery climate of war, ordinary natures tend to move more ponderously: stronger and more frequent stimuli are therefore needed to ensure that momentum is maintained’ (p. 217). However extreme and ‘absolute’ the political object of the war might be, it could not in itself overcome this ‘ponderousness’. ‘Unless an enterprising martial spirit is in command,’ maintained Clausewitz, ‘a man who is as much at home in war as a fish is in water . . . inactivity will be the rule, and progress the exception.’

If there was no such ‘martial spirit’ to provide an impetus, no popular pressures involved and no great goals in view, a campaign was likely to make slower and slower progress. War became ‘something half- hearted’ (p. 218) as it had been in the eighteenth century, and came to resemble nothing so much as a Spiel, a game of chance. We have seen how the element of hazard and luck gave something of this quality to all wars, but without political or popular motivation and in the absence of a bold commander war resembled not so much a play for high stakes as ‘haggling over small change’. It was when this happened, said Clausewitz, that the minor skills of the generals of the rococo period, their feints and manœuvres and ambushes, acquired an exaggerated importance and were wrongly – and disastrously – believed to constitute the entire art of war.

According to this explanation. then, even if the nature of war in the abstract was something absolute, the nature of the men who fought the wars constrained it and made it fall short of its Vollkommenheit, its ‘perfection’. Perhaps war should be limited, or at least determined, by its political objective; but certainly it would be limited, or at least constrained, by human weakness, by the intrinsic element of ‘friction’. In order to achieve the objectives of even a limited war it would be necessary to make efforts above the ordinary – to take the model of ‘absolute war’ as one’s target. So although the fighting of an ‘absolute war’ was only one, and perhaps the least common, of the possible demands that statesmen were likely to make on the military, the military commander had to keep it in sight as an ideal if he was to fight even limited wars of policy effectively; ‘to approximate to it when he can and when he must’ (p. 58). With that it might be thought there went the corollary, as Bismarck was to discover a generation later, that the statesman needed to keep a sharp eye on the soldier if the latter was not to overshoot the mark and turn a limited war into an absolute one. But this was an aspect of the matter that Clausewitz failed to consider.

I have made the point that the full importance of this distinction between the two types of war dawned on Clausewitz not when he was writing one of his more analytic chapters, but in the middle of the very long section, full of detailed topographical and tactical information, that he devoted to defence. It is a book that editors of potted versions of Clausewitz often and understandably prefer to omit, but in doing so they deprive their readers of much of the essence of Clausewitz’s thought. In particular the prescriptive elements in his work, the specific proposals for the conduct of a campaign which he lays down in his final book ‘On War Plans’, can be understood only in the light of the principles he worked out in meditating about the defence – something he did so comprehensively that it left him with very little to add in the subsequent section, on ‘The Attack’.

井冈山卫士

We deliberately use the phrase ‘with the addition of other means’ because we also want to make it clear that war in itself does not suspend political intercourse or change it into something entirely different . . . The main lines along which military events progress, and to which they are restricted, are political lines that continue throughout the war into the subsequent peace . . . War cannot be divorced from political life; and whenever this occurs in our thinking about war, the many links that connect the two elements are destroyed and we are left with something pointless and devoid of sense. (p. 605)

This formulation has taken us a long way from the simple concept of ‘the two types of war’. Given that considerations of policy are paramount, and knowing that the requirements of policy may be almost infinitely various, war can surely be of any kind, not only of two. It might be, as Clausewitz put it, a ‘terrible two-handed battlesword’ capable of settling matters at a single stroke, or it might be ‘a harmless foil fit only for thrusts and feints and parries’ (p. 606). But it might also be anything in between.

The implications of this possibility of gradation, as opposed to the sharp distinction between two categories, Clausewitz did not live to explore. He never really considered the territory that lay between his two ‘models’. But he did make the point, one vividly present to the mind of any survivor of the Jena campaign, that it took two to fight a limited war. If your opponent was prepared to exert himself to the utmost to achieve his objective, you had no choice but to do the same. The logical escalation to ‘absolute war’ had then to be accepted. For that reason, he insisted, the strategist must always have the ideal of absolute war clearly in mind. You had to approximate to the ideal form ‘when you can and when you must’ (p. 581).

According to this formulation, then, the nature of war was determined not so much by cultural circumstances as by the reasoned decisions of the political leaders who called the war into being. But Clausewitz advanced yet a third explanation for the limited nature of most wars, this one intrinsic to the conduct of war itself.

Clausewitz was obviously fascinated by a paradox in the conduct of war to which he reverted again and again – something he termed ‘the suspension of the action’. In principle one might expect to find that war was a matter of continuous, violent, and mutually murderous activity. In practice armies, even at the height of a campaign, often spent most of their time sitting around doing nothing. It was one of those insights into the realities of military life that place Clausewitz in a class of his own as a military analyst, for it really is this tedious inactivity, quite as much as the element of ‘friction’, that distinguishes the reality of war from the neat models of the strategic theorist. War, as it has been well said, consists of nine parts boredom to one of fear.

Clausewitz’s explanation of this phenomenon was initially linked to his analysis of the interaction between attack and defence. It was seldom, he pointed out, that both sides simultaneously had a strong incentive to take the initiative. (One of the few occasions when this did happen was at the outbreak of the Great War in 1914, when all the major belligerents launched offensive operations.) However offensive the intentions of both belligerents might be, it was unlikely that both would choose the same moment to attack. One side might want to wait until it had built up its strength, and so remained for the time being on the defensive. That defensive posture, in its turn, might appear so formidable as to deter its opponent from attacking, so that he also decided to wait for a better moment. As a result nothing very much might happen for quite a long time.