1. As pointed out in my last dispatch, the object of these operations was to gain a local success by a sudden attack at a point where the enemy did not expect it. Our repeated attacks in Flanders and those of our allies elsewhere had brought about large concentrations of the enemy's forces on the threatened fronts, with a consequent reduction in the garrisons of certain other sectors of his line.
Of these weakened sectors the Cambrai front had been selected as the most suitable for the surprise operation in contemplation. The ground there was, on the whole, favorable for the employment of tanks, which were to play an important part in the enterprise, and facilities existed for the concealment of the necessary preparations for the attack.
If, after breaking through the German defense systems on this front, we could secure Bourlon to the north, and establish a good flank position to the east, in the direction of Cambrai, we should be well placed to exploit the situation locally between Bourlon and the Sensée River and to the northwest. The capture of Cambrai itself was subsidiary to this operation, the object of our advance toward that town being primarily to cover our flank and puzzle the enemy regarding our intentions.
The enemy was laying out fresh lines of defense behind those which he had already completed on the Cambrai front; and it was to be expected that his troops would be redistributed as soon as our pressure in Flanders was relaxed. He had already brought large forces from Russia in exchange for divisions exhausted in the struggle in the western theatre, and it was practically certain that heavy reinforcements would be brought from east to west during the Winter. Moreover, his tired divisions, after a Winter's rest, would recover their efficiency.
For all these reasons, if the existing opportunity for a surprise attack were allowed to lapse, it would probably be many months before an equally favorable one would again offer itself. Furthermore, having regard to the future, it was desirable to show the enemy that he could not with impunity reduce his garrisons beyond a certain point without incurring grave risks.
Against these arguments in favor of immediate action I had to weigh the fact that my own troops had been engaged for many months in heavy fighting, and that, though their efforts had been uniformly successful, the conditions of the struggle had greatly taxed their strength. Only part of the losses in my divisions had been replaced, and many recently arrived drafts, still far from being fully trained, were included in the ranks of the armies. Under these conditions it was a serious matter to make a further heavy call on my troops at the end of such a strenuous year.
On the other hand, from the nature of the operation, the size of the force which could be employed was bound, in any case, to be comparatively small, since success depended so much on secrecy, and it is impossible to keep secret the concentration of very large forces. The demand made upon my resources, therefore, should not be a great one.
While considering these different factors, preparations were quietly carried on, so that all might be ready for the attack if I found it possible to carry it out. The success of the enemy's offensive in Italy subsequently added great force to the arguments in favor of undertaking the operation, although the means at my disposal for the purpose were further reduced as a consequence of the Italian situation.
Eventually I decided that, despite the various limiting factors, I could muster enough force to make a first success sufficiently sure to justify undertaking the attack, but that the degree to which this success could be followed up must depend on circumstances.
It was calculated that, provided secrecy could be maintained to the last moment, no large hostile reinforcements were likely to reach the scene of action for forty-eight hours after the commencement of the attack. I informed General the Hon. Sir Julian Byng, K. C. B., K. C. M. G., M. V. O., to whom the execution of the plans in connection with the Cambrai operations was intrusted, that the advance would be stopped by me after that time, or sooner if necessary, unless the results then gained and the general situation justified its continuance.