J.C.S. Files

Memorandum by the Chief of Staff to the Supreme Allied Commander Designate (Morgan)1

most secret
Enclosure to C.C.S. 320

Digest of Operation Rankin

Recommendations for the Courses of Action to be followed in North-West Europe in the event of substantial weakening of German resistance, or withdrawal from Occupied Countries or unconditional surrender occurring between the 1st November, 1943, and the 1st May 1944.


1. The latest review (J.I.C. (43) 324 of 3 August 19432) by the J.I.C. of the enemy’s present situation and his possible plans and intentions during the remainder of 1943 shows that the recent reverses on the Russian front, the breach developing in Italy and the Balkans, the set-back suffered by the U–boat campaign and the ever-increasing Allied air offensive, all combine to create a position which (in the opinion of the J.I.C.) must appear to the German leaders as verging on the desperate. The limiting factor for the enemy being availability of forces, the gathering threat in Italy and the Balkans may well lead him to find reserves at the expense of the ground and air forces now located in Norway, Denmark, the Low Countries and France. Nor is it beyond the bounds of possibility that an imminent threat of complete disaster on the Russian front might induce him to abandon altogether his occupation of Western and probably Southern Europe, in order to concentrate all available forces against the Russian menace, postpone the hour of final defeat and insure the ultimate occupation of Germany by Anglo-American rather than by Russian forces.

conditions of a return to north-west Europe during the winter 1943–44

2. It follows from the above that it has become a matter of urgent necessity to prepare for a return to the Continent during the winter 1943–44. The possible alternative conditions of return are:—

  • Case A.—Such substantial weakening of the strength and morale of the German armed forces as will permit successful assault with the Anglo-American forces prior to the target date of Overlord .
  • Case B.—German withdrawal from the occupied countries.
  • Case C.—German unconditional surrender and cessation of organized resistance in North-West Europe.

In Cases A and b our object is to effect a lodgment on the Continent from which we can complete the defeat of Germany; our object in Case C is to occupy as rapidly as possible appropriate areas from which we can take steps to enforce the terms of unconditional surrender laid down by the Allied Governments. Inherent in all cases will be the rehabilitation of liberated countries. The three cases are considered in succession below.

case a.—courses of action for a return to the continent in the event of substantial weakening of german resistance in france and the low countries

3. Excluding airborne troops and tank brigades, it is calculated that the number of Allied Divisions operationally and administratively ready on the 1st November, 1943, will be eight, on the 1st January, 1944, seventeen, and on the 1st March, 1944, twenty-three. The approximate Naval Assault Forces available on these dates will be respectively one, two-three, and five. The Metropolitan Air Force will be available for cover and support and one composite group of the Tactical Air Force should be available by the end of 1943. It is considered that with these resources the following operations would be practicable. During November and December 1943 an assault could only be undertaken on a narrow front against a weakly-held sector of the coastline, provided that there are clear indications that France and the Low Countries have been almost entirely denuded of reserves, and that German resistance is on the point of collapse. During January and February 1944 an assault could be undertaken against weak opposition to secure a strictly limited objective. From March 1944 onwards an assault with a more ambitious role might be undertaken, provided the strength and morale of the German troops and, in particular, of German reserves, are markedly below the maximum acceptable strength for Operation Overlord . Clearly in all three cases the overriding condition of adequate reduction in the present fighting value of the G.A.F. on the Western front, and an inability of the German Command to bring up important reserves, must pertain.

4. As for the area of assault, the choice in Operation Overlord was narrowed down to the alternatives of the Pas de Calais and the Cotentin–Caen sectors. The Pas de Calais is the pivot of the whole German defensive system, and it may be expected that the defenses there will remain strong to the end; it is therefore concluded that the assault area in the present case should be the same as for Overlord , [Page 1012] i.e., Cotentin–Caen. As maintenance over beaches and the construction of artificial ports would prove too hazardous in winter, it will be essential to capture the port of Cherbourg and as many minor ports as possible within 48 hours. The plan for Overlord would therefore have to be modified to meet this special requirement. There are obvious advantages in having the same area for either operation; for in the early months of 1944 our preparations for Overlord will be well advanced, and it would be difficult at that stage to change the area of assault to some different part of the coast.

5. The strategic recommendations for Case A may accordingly be summarized as follows:—

No assault against organized resistance will be feasible before the 1st January, 1944, unless there are clear indications that German resistance in the West is on the point of collapse, and measures are taken in time to make the Naval Assault Forces available for operations by recourse to special manning expedients.
Subsequent to that date, an assault elsewhere than in the area selected for Overlord is unlikely to be feasible or advisable.
If a sufficiently drastic reduction in the morale and strength of the German armed forces takes place, operations against organized opposition could be undertaken in January or February 1944 to capture the Cotentin Peninsula, or in March or April 1944 to put up a modified Overlord plan into effect. In either case the plan must provide for the capture of the port of Cherbourg within the first 48 hours.
As in the case of Overlord , diversionary operations in the Pas de Calais area, and from the Mediterranean against the South of France will probably be essential.

case b.—courses of action for a return to the continent in the event of a german withdrawal from the occupied countries

6. It is probable that if the enemy is obliged to make withdrawals from Western Europe he will first withdraw his forces from his extremities, i.e., from Norway in the North and from South-Western and Western France in the South. If this occurs, we should require, for political as well as strategic reasons, to send some forces to occupy the areas so liberated; but it would be important that we should not tie up our main forces far from the eventual center of action.

7. In Norway, establishment of certain bases for Coastal Command Aircraft and Naval Forces is likely to be most desirable. It is probable that requirements can be limited to the establishment of bases in Northern Norway for aircraft of Coastal Command for the anti-submarine protection of shipping on passage round the North Cape; the development of Stavanger and Bergen as bases for aircraft of Coastal Command and light Naval Forces to blockade the entrance to the Baltic, and for the conduct of small offensive operations; and the establishment of surface warning sets (Radar) on the South coast of [Page 1013] Norway. It is considered that forces of the order of one brigade group would be required for Northern Norway, and one division for Southern Norway, to secure the naval and air bases and support the Norwegian contingent in its task of rehabilitation.

8. In France, it is probable that the first point of withdrawal would be Bordeaux, followed in succession by the other ports on the Western coast; the Channel coast and in particular the Pas de Calais would remain the last areas to be uncovered. Once withdrawal begins it is likely that it will eventually continue as far as the Siegfried Line, owing to the difficulty of holding any intermediate position with an economical force.

9. The governing condition of our return is that we must have ports, since maintenance over beaches in winter is not practicable. If the enemy withdraw from South-Western and Western France, it is proposed that we should send a brigade group each, together with minimum necessary covering air forces, to occupy Bordeaux, Nantes and Brest. The purpose of occupation of Bordeaux would be the rehabilitation of South-West France; the purpose of occupation of Brest and Nantes would also be partly the rehabilitation of France, but mainly the preparation, as a long-term policy, for the entry and maintenance of United States Forces direct from the United States. Demands to commit larger forces to these areas should be firmly resisted, and the first point of entry for our main forces should not be West of Cherbourg. The Northern extension of the German defensive position on the Siegfried Line would probably prevent our use of Antwerp, in which case the major ports available for our return would be Cherbourg, Havre and Rouen. It is impossible to forecast the turn that operations would take, since our advance would be dependent on the enemy’s withdrawal policy. It must be assumed that the enemy’s demolitions will be thorough, and, therefore, it cannot be expected that our rate of advance will be swift. Moreover, rapid airfield construction, as proposed in Overlord , is impracticable in winter, and a more permanent and lengthy type of construction will be required. The capture of existing airfields is, therefore, of increased importance. A likely course of events is that an initial landing might be made at Cherbourg, followed by later landings at Havre and Rouen, and not long afterwards by the introduction of reinforcements and stores through the Pas de Calais ports. Our general intention should be to press Eastwards as fast as possible, opening up additional ports as we go, with the further object of establishing airfields in the Pas de Calais and in Belgium, from which the Tactical Air Force can complete the destruction of the German Air Force and the strategic bomber force can intensify their attack on Germany at closer range when the advance [Page 1014] Eastwards has gone sufficiently far to make this profitable. Under the condition of German withdrawal, deficiencies in the strength of the Tactical Air Force can be made good at the expense of the static fighter defense system of the United Kingdom. In this way enough squadrons could be made available to take full advantage of airfields prepared by the Army on the Continent, while additional air support could still be provided from bases in the United Kingdom.

10. The strategic recommendations for Case B may accordingly be summarized as follows:—

That the port of Cherbourg be the first place of entry for our main forces.
That as the German withdrawal proceeds, our main forces be based on Cherbourg, Havre and Rouen, supplemented as necessary by the smaller ports further East.
That the port of Bordeaux be occupied in the first instance by a small force only for the sole purpose of rehabilitation of South-West France.
That the ports of Brest and Nantes be similarly occupied by small forces only, partly to assist in the rehabilitation of France, but mainly to prepare, as a long-term policy, for the entry and maintenance of United States Forces direct from the United States.
That as large forces as possible from the Mediterranean be dispatched to occupy the ports of Marseilles and Toulon, and subsequently to move Northwards on Lyons and Vichy, and thereafter as required.

case c—courses of action for a return to the continent in the event of german unconditional surrender and the cessation of organized armed resistance in north-west europe

11. The object is to occupy, as rapidly as possible, appropriate areas from which we can take steps to enforce the terms of unconditional surrender imposed by the Allied Governments on Germany; and in addition to carry out the rehabilitation of the Occupied Countries.

12. A consideration of the areas of strategic importance leads to the conclusion that the best use of our limited land forces lies in the speedy occupation in adequate force of the Jutland Peninsula, the adjacent great ports of Bremen, Hamburg and Kiel, and the large towns in the valleys of the Ruhr and the Rhine. It is considered that the forces required for occupation of these areas would amount to seven divisions for Denmark and North-West Germany, six Divisions for the Ruhr, eleven Divisions for the valley of the Rhine; making a total in all of twenty-four Divisions.

13. In addition to the forces required for occupation of Germany, further forces will be required for rehabilitation of the Liberated Territories and to assist in the disarmament of Germany. It is considered that the following forces will be required in support of the contingents [Page 1015] of the Nations concerned, or in the case of Denmark supplementary to the field force formations given in paragraph 12 above; one division and one brigade for Norway, one brigade for Denmark, two brigades for Holland, four brigades for Belgium; and in the case of France, two field force divisions for Paris and Northern France, two field force divisions for the Mediterranean ports and South France, and six brigades for the Atlantic and Channel ports. Except where it is explicitly stated that field force divisions will be required, full use should be made of non-field force formations in the above role.

14. Both in the case of Germany and in the case of liberated territories, it will be necessary for adequate air forces to form part of the occupying force. In Germany, their role will be to take immediate action to overcome any resistance to our terms, to take punitive action against local disorder and to be a reminder to the German people of the main strategic bomber force which will remain based in the United Kingdom. Adequate air forces for occupation of areas near key points in Germany and liberated territories are available in the United Kingdom and the whole resources of the Metropolitan. Air Force will be available for reinforcement.

15. The use of large forces in the dual task of rehabilitating the liberated territories and occupying strategic areas in Germany is a problem of such complexity that the greatest simplicity in plan is required if mistakes of far-reaching consequence are to be avoided. It is considered that the best plan will be to keep to the alignment proposed for Overlord , i.e., to dispose the American forces on the right of the front and the British forces on the left. It is thus contemplated that the American sphere of responsibility will extend from the Rhine at the Swiss Border to Düsseldorf, and will also include France and Belgium; while the British sphere of responsibility will include the Ruhr and North-West Germany, Holland, Denmark and Norway. In the liberated countries there should be representative forces of both nations.

16. It is clear that for both political and military reasons speed of entry will be of the first importance. It may be possible to use air transport to a limited extent, but the bulk of our forces will have to be carried by sea. In the case of reentry through Copenhagen, Bremen and Hamburg, minesweeping is likely to impose short delays. The most suitable port of entry for the formations to occupy the Ruhr appears to be Rotterdam, while that for the forces for the Rhine Valley will be Antwerp.

17. The comparison of requirements against availability of forces at different dates is as follows, providing the Bolero program is maintained and the forces earmarked to return from the Mediterranean are [Page 1016] received. The requirement is constant at 26 divisions and the availability of divisions shown excludes airborne troops and tank brigades:—

a. March 1944.
23 divisions administratively ready for mobile operations.
4 divisions administratively incomplete.
Total 27 divisions.
b. January 1944.
17 divisions administratively ready for mobile operations.
7 divisions administratively incomplete.
Total 24 divisions.
c. November 1943.
8 divisions administratively ready for mobile operations.
8 divisions administratively incomplete.
Total 16 divisions.

In view of the non-operational and semi-mobile nature of the tasks, the total figure shown in each case may be taken as the availability. The deficits therefore are two divisions in January 1944, and ten divisions in November 1943. It is proposed that these deficits should be made good when emergency arises by the dispatch of Allied forces in the Mediterranean and of the United States divisions earmarked for Operation Overlord . Apart from these forces it is proposed that Allied forces in the Mediterranean should supply one United States and one British division to accompany the forces of the French Committee of National Liberation, for employment in Southern France.

18. It is emphasized that the forces given in paragraph 12 above are the minimum land forces which will be required initially to obtain control in the Rhine Valley, the Ruhr, the entrance to the Baltic and in North-Western Germany. The ultimate size of forces of occupation will depend on the requirements and terms of occupation laid down by the Allied Governments.

19. The strategic recommendations for Case C may accordingly be summarized as follows:—

That the sphere of the Supreme Allied Commander include the whole of France, Luxemburg, Belgium, Holland, Denmark, Norway and such portion of enemy territory as the Allied Governments may decide. It is assumed that this will include at least the Rhine Valley, the Ruhr and North-West Germany.
That, as soon as the situation permits at the time of German unconditional surrender, Allied Forces based in the United Kingdom be dispatched:
To occupy and control the Valley of the Rhine from the Swiss to the Dutch frontiers, together with the area of the Ruhr, and insure disarmament of German armed forces returning from occupied territory.
To occupy and control Denmark, Schleswig, Holstein, the Kiel Canal, and the cities of Hamburg and Bremen, and insure disarmament of German armed forces in those areas.
To open selected ports in the West coast of France and the Low Countries to establish control in the capitals of those countries, to institute measures of rehabilitation, and to assist as may be required in the disarmament of German armed forces.
To establish control in Norway, to rehabilitate the country, and insure disarmament of German armed forces.
That, simultaneously, Allied contingents from the forces based in the Mediterranean be dispatched to open selected ports on the Mediterranean coast of France, to establish control at Vichy, to institute measures for the rehabilitation of Southern France, and to assist as may be required in the disarmament of German armed forces. These Allied forces to come under operational control of the Supreme Allied Commander on arrival in France.
That, under the general direction of the Supreme Allied Commander, France, Belgium and the Rhine Valley from the Swiss frontier to inclusive Düsseldorf be regarded as a sphere under the control of the United States forces, with British representation in the liberated countries.
That, under the general direction of the Supreme Allied Commander, Holland, Denmark, Norway and North-West Germany from inclusive the Ruhr Valley to Lübeck be regarded as a sphere under the control of British forces, with United States representation in the liberated countries.

concluding recommendations

20. Certain general recommendations emerge from the above study of Rankin :

The forces allotted for Overlord should be considered as equally available for Rankin , if the occasion should arise.
The appointment of the Allied Air Commander-in-Chief and Staff, and the provision in the United Kingdom of the Commanding General, Staff and headquarters of the United States Army Group are of urgent importance and should be undertaken forthwith.
If the strategic recommendations in this paper are accepted in principle, the British and United States Governments should be invited, as a matter of urgency, to lay down a policy to govern the conduct of the Civil Affairs Staff in the establishment of military governments in enemy territory to be occupied by our troops, and a policy to govern the establishment of indigenous administrations in the liberated Allied territories.
That no time be lost in setting up nucleus combined American/British Civil Affairs Staffs in London for Germany and for each Allied country and friendly country, and such other countries as may [Page 1018] be decided to lie within the sphere of the Supreme Allied Commander, to study in detail the problems involved and to make, without delay, detailed plans for the organization of civil administration therein.
That plans be made forthwith, complete in every detail, for the rapid recruitment in reserve units on a para-military basis of British civil resources in technical personnel, labor and equipment for employment on the Continent, especially for airfield construction. In order to avoid any interference with the progress of current vital work, such as the Bolero and airfield construction programs, these plans only to be put into effect when the emergency arises.
It will be desirable to undertake a campaign of propaganda among our own people to bring to their notice the necessity for widespread participation in the campaign in prospect. Our Service resources will be stretched to the uttermost, and will need every sort of civilian administrative support if they are to develop their full force at the decisive point or points. Provision of this support may well entail sacrifices on the part of all classes of the community.
Close attention should be devoted to the question of collaboration with the U.S.S.R.

  1. Circulated under cover of the following note by the Secretaries of the Combined Chiefs of Staff (C.C.S. 320), August 20, 1943: “The Enclosure is a digest of the plan for Operation Rankin which has been prepared by the COSSAC Staff.”

    For the discussion of this paper at the 115th Meeting of the Combined Chiefs of Staff, August 23, 1943, see ante, p. 940.

  2. Not printed. For a summary of this paper telegraphed to Hull by the Ambassador in the United Kingdom (Winant) on August 14, 1943, see ante, p. 512.