Ludendorff had acted on the supposition that the enemy would do what they in his place would do, Tannenbcrg would probably never have been fought, or, if fought, would have been merely a battle to gain time. As it was, when pros and cons were prac- tically in equilibrium and the fate of East Prussia depended on the choice made, one thing turned the scale a conviction derived from intimate knowledge of the Russian army, that in spite of recent reforms and of the evident war-readiness of the enemy, slowness was an inherent character of his leadership. But for this, the decision to leave a mere handful of cavalry in front of Rennenkampf's advancing army, and to concentrate every available rifle and gun against Samsonov, would have been simply trusting to luck, and although luck must always play a part in war, it is the art of command, whether the com- mand be personal or in commission, to reduce this part to a minimum. 1
To answer the question, then, the commander and his opera- tions assistants must have an intelligence staff which will con- stantly supply them with a picture of enemy movements, posi- tions and intentions. To construct this picture a high degree of military training is necessary, especially in the senior ranks, and the personnel in these ranks must be drawn from the same sources and trained to the same level as similar personnel on the opera- tions staff. But, given this equipment, the intelligence staff officer need have little knowledge of current events and inten- tions on his own side. The fewer his prepossessions the better. On this point there has been in the past not a little contro- versy. In the French command regulations of 1913 it was laid down that the duty of intelligence was to seek for information on the topics and in the directions indicated by the command. In all armies, this principle was accepted so far as cavalry recon- naissance was concerned, the capacities of that arm, and its fragility (exhaustion of horses) made it essential that its activ- ity should be directed to obtaining definite answers to specific questions. The same applies to some extent to information- gathering by other front agencies. And so far as they are con- cerned the wisdom of the doctrine is unquestionable. In a local tactical situation the presence of enemy forces in certain posi- tions, or their movements in certain directions, can as a rule bear only one meaning. But it is altogether different in the case of groupings and movements of major importance. Here data, even if complete and still more if incomplete, may be wholly misleading unless interpreted by men both qualified in respect of military judgment and also free from preconceived ideas. Instead of placing the intelligence staff in the position of the enemy, with instructions to compile a picture of his grouping and intentions, the doctrine embodied in the French regulations fetters it by compelling it to start from prepossessions. It is to this principally that must be attributed the miscalculations of the French intelligence in Aug. 1914 miscalculations that were nearly fatal to France. It was assumed a priori that only first- line troops would be employed by the Germans, and the Deux- ieme Bureau directed its efforts to identifying the various active army corps as they stood in the strategic deployment. In this it succeeded, but the presence of many duplicate corps of reserves, bearing the same numbers and assembled in the same areas as their parent active corps respectively, passed unnoticed Thus the strength of the enemy's troupes de choc came to be estimated on the eve of battle at 40 divisions, where- as in reality there were 68.
When the intelligence staff is regarded as the mirror of the enemy the risk of such miscalculation is minimized. The mirror may be dark at times, and a priori reasoning by the com- mand may then be necessary to supplement the picture, but that is a very different matter from drawing a picture for the intelligence staff to fill in. One argument, and one only, in favour of coloured intelligence was and is tempting the
1 As an example of the reverse, the battle of Worth in 1870 may be quoted. If, in the circumstances described in 28.834, there had been present on the German side any commander or staff officer with an intimate knowledge of the habits of the French army, the battle would never have been fought.
psychological. General Berthelot has admitted that in the information given by French G.H.Q. to subordinate command- ers the enemy forces were sometimes deliberately understated so as not to alarm the recipients. Such a proceeding the risks of which are obvious is equally conceivable as between an intelligence staff and a command staff. But it is the less likely in proportion as the intelligence staff is allowed to disinterest itself in the events and intentions of its own side. And although it may sometimes be in the general interest that a subordinate's local fears should be overcome by means of a subterfuge, a G.H.Q. must always face the facts. That is the essential quality of its supreme responsibility. Correspondingly, the command is entitled to insist on the facts being presented to it. The intelligence staff need not of course produce at every moment the mass of small items on which its " appreciation " is based, nor should this appreciation be liable to be overruled by a different interpretation of the same evidence on the part of the command (herein its position differs from that of an operations staff). But it cannot expect the " appreciation " to be accepted unless it possesses the confidence of the command, and there is no surer way of forfeiting this than by crying " wolf " too often. 2
In this modern conception of military intelligence it is evident that the chief of intelligence bears a responsibility that is only less than that of the commander-in-chief or his deputy, the chief of the general staff. The personal rank of the head of the intelligence branch may be high or may be comparatively low, the numerical strength of the organization that he controls may vary from a dozen or two to some thousands not including " agents " in either case and the scope of the work may be purely military and local or may cover almost the whole military, political, industrial and economic field as it did in the World War. But whatever his rank, his system and his scope in any particular case, his function is unlike that of any other branch of the staff. He " commands the enemy's army," that is, he interprets to the best of his ability that independent will over which the commander-in-chief exercises no authority.
The collection, sifting and interpretation of data concerning the enemy's resources, movements and intentions constitute what is usually called " offensive " or " positive " intelligence. There is another branch of intelligence work known as " defen- sive " or " negative " intelligence, but which might more correct- ly be called counter-intelligence This consists in preventing the enemy from obtaining, or at least from gathering in, the data for his own offensive intelligence. Within its scope fall, besides the obvious task of detecting spies, preventive measures of various kinds such as the enforcement of discretion within one's own army, and the registration of aliens' movements. In some cases, as in Great Britain, the convenience of having all secret services handled by a single staff has produced the combination of counter-intelligence work with that part of offensive intel- ligence which operates by secret means. Collectively, this service is known in the British organization as Intelligence B or I(b), in contradistinction to Intelligence A or I(a) which obtains information openly and collates and interprets all " offensive intelligence " material however obtained.
(B.) Positive Intelligence. The gathering, synthesis and interpretation of intelligence in war are all more difficult than in peace. The work of agents in a belligerent country becomes difficult as well as dangerous. A state at war brings into opera- tion all the mechanism of counter-intelligence, and while the mere collection of facts is perhaps easier because of the pre- dominance and priority of military over other elements in the national life, the transmission of these facts to the intelligence office which counts them is exceedingly difficult. In the field of operations, information at once becomes more plentiful than
2 It goes without saying that this confidence can also be forfeited when events show that the enemy's situation has been presented in too unfavourable a light, but the more thoroughly the intelligence staff absorbs the enemy's " atmosphere " the less likely this is to happen, since there are few situations in war in which one side is more confident than the other is anxious; moreover, the less the intelli- gence staff is exposed to the pressure of its own side's " atmosphere " the less it is likely to make the wish the father of the thought.
