Lessons Learned at Dieppe (II)
(a) The chances and opportunities of an assault landing are extremely difficult to gauge in advance. The military plan must, therefore, be flexible in order to enable the Commander to apply force where force has already succeeded.
(b) The axiom, normal in land warfare, that it is unprofitable to reinforce a hold-up, is even more strongly applicable in the assault phase of an opposed landing, because, in the latter type of operation a hold-up almost invariably means that there is little or no room for manœuvre. Thus, to put in more troops, where the leading waves have not succeeded in penetrating the immediate defenses, is likely to increase the target without increasing the prospects of success. This was again brought out at Dieppe.
(c) If the military plan is to be flexible, then certain basic requirements must be accepted and must be embodied in the general arrangements for the operation. These requirements are discussed in paragraphs 349 to 354.
(d) It must be recorded, however, that with the state of training of the landing craft crews which prevailed at the time of the Dieppe operation, a flexible military plan could not have been put into execution. It is only by the formation of the permanent Naval forces advocated in paragraph 345 (a) that the requisite standard of training can be achieved. The greater the number of experienced Royal Navy officers available, the shorter will be the period of training required by theses forces.
349. The Width of the Front Which Can Be Assaulted
(a) If flexibility is to be a true characteristic of the plan, then the initial assault must cover several landing places. If, to take an extreme case, the assault is made across only one beach, then there is little that a military commander can do to make his arrangements flexible, for he will be dependent on success in one area, and must either batter hs way through or fail.
(b) It must be appreciated, however, that the following factors will qualify and limit the width of the front and the number of landing places which can be attacked with advantage.
(i) The frontage which can be controlled by the Headquarters organization which it is possible to set up on the spot and the number of physically suitable beaches within that frontage:
(ii) The amount and type of support from the naval forces and the air forces which can be made available.
(iii) The size of the military force and the nature and composition of the Naval assault force which have been allotted to it and the organization and skill of that force.
350. Strength of the Assault in Relation to the Follow-Up Force
(a) In a combined operation there are always present two strong, but natural, tendencies both of which militate against flexibility. The first is to allocate too great a strength to the assault in order to ensure success in this essential phase, while the second is to issue precise and comprehensive orders to the whole force in advance to that each unit and sub-unit shall know exactly what is required to accomplish and how to do it.
(b) In a small scale raid, such an allocation of strength to the assault and such precision in the orders may be permissible, because the operation will, in all probability, depend upon immediate penetration in a certain area and upon the completion of definite tasks within a restricted time limit.
(c) In larger operations, however, it becomes more and more necessary to weigh the balance with care and judgement, bearing in mind that the greater the strength allotted to the assault, the weaker the force that can be held afloat- the more rigid the plan and the less the chance of switching landing craft and troops to areas where success has been attained and through which it should be exploited.
(d) From the military point of view, therefore, the aim must be to allocate to the assault the minimum force required for success and to retain afloat the maximum force ready to follow in and exploit success wherever it has been achieved.
(e) From the military point of view, however, there can be no objection if the support given by Naval vessels and Air forces to the assault is excessive and the criterion should be the maximum which can be made available rather than the minimum which might be adequate.
(f) The problem is, however, easier to state than to solve.
351. Control and Communications
(a) The more flexible the plan and greater the sub-division of the military force, the more essential it becomes that the control and communications arrangements should be of the highest standard.
(b) It will not, in fact, be possible to carry out a flexible plan successfully unless the Commanders receive a constant series of accurate pictures of the situation on shore and unless, when in possession of such information, they are able to take rapid executive action.
(c) The following are the essential requirements:
(i) A joint organization, in which the arrangements for each service fit in with those of other services, and are available for emergency use by all. This must be centered in an H.Q. Ship, which should be duplicated as far as possible to meet the risk of loss. Such a ship must include carefully laid-out arrangements for Command, Staff-work, and communications, planned conjointly. These can only be satisfactory if the ship is properly fitted in permanent form.
(ii) Adequate Naval Signal organization for the control of the numerous ships and landing craft engaged in the operation.
(iii) Alternative channels for the passing of information from shore to ship and vice versa. In this connection, it is to be noted that reliance must not be placed on a single method. For example, wireless links should be duplicated whenever possible, and visual signals, loud-hailers and any other available means, should be fully exploited.
(iv) On Army channels of communication no effort must be spared to establish and exploit alternative channels by which information can, if necessary, be passed. The fact that the same intelligence may reach the Military Commander from various sources and at about the same time, is not in practice either a waste of effort or over-insurance. The essentials are that the information should be sent, that it should arrive and that links should be available by which it can be acted on with the minimum delay.
(v) In the Naval organization, on the other hand, although duplication of channels must be practised as far as possible, the large number of units with limited equipment which it is generally necessary to keep under centralised control makes essential the most rigid discipline and economy of signaling, and the duplication of reports cannot be accepted. The originator of any signal must, therefore, first consider whether or not his signal is really necessary for the conduct of the operation.
(d) Good information and the power to act upon it are essential to all operations. It cannot be too strongly emphasised that the need for such facilities is particularly apparent in the assault phase of a combined operation when a narrow stretch of water may, through lack of them form an impenetrable barrier.
(e) Much may depend upon the efficiency or otherwise of the communications between ground or ship and the aircraft supporting the operation.
352. Knowledge of the Operation among all Units and Ranks
(a) The more flexible the plan the more important it is that every officer, N.C.O. and man should know the intention of his superior and the outline of the operation as a whole and the detail of the primary task allotted to his own unit and to those on his flanks. Without such knowledge, units and individuals faced by unexpected circumstances cannot be expected to know how best to take advantage of a particular situation or how to further the operation as a whole.
(b) Dissemination of knowledge to the extent contemplated in the preceding sub-paragraph requires time and access to certain facilities such as models, photographs and silhouettes. The use of such facilities is, of course, bound up with the difficult problem of security which is dealt with later. (See paragraph 367.)
(a) No combined operation should be launched until it has been adequately rehearsed.
(b) Rehearsals need not necessarily always be complete. For instance, the operation on land can be practiced frequently without the actual disembarkation from landing craft being included. Similarly, the inter-communication system between ships, shore, and air can be worked up without all sea, air and land forces being present.
(c) After partial rehearsals, rehearsals on a larger scale may be desirable. No general rule can be laid down and commanders must consider each case on its merits.
(d) It is particularly important that all sea-borne military headquarters should be given adequate opportunity for practice. They will, at any rate, during the initial stage of an operation be working in unfamiliar and probably cramped conditions. The best layout of the headquarters and the best placing of inter-communication and intelligence staffs cannot be satisfactorily settled by discussions over a diagram. Such discussions must terminate in full-dress rehearsals with all shore headquarters fully represented.
An excellent book on the British effort to develop amphibious warfare capabilities is Bernard Fergusson, The Watery Maze: The Story of Combined Operations (1961). It’s interesting that the development of these capabilities in the European theater seems to have had very little cross pollination with what the US Navy, Army, and Marine Corps were doing in the Pacific. One forgotten aspect seems to be the US Army’s highly developed capabilities employed in the Pacific, including quite different methodologies from the Marine Corps. It’s been years since I’ve read about this, and I don’t know if there’s a single good book on the topic, but it’s interesting to see that the two services essentially charged with an identical task, worked without a lot of dialogue between them, and developed distinctively different approaches. Given that the Americans didn’t even talk to each other, it’s not much of a surprise that the Americans and the British were not more fulsome in their sharing of methods and lessons, either.