Foreign Relations of the United States, Conferences at Washington and Quebec, 1943

J. C. S. Files

Memorandum by the British Joint Planning Staff¹

secret
Enclosure to C.C.S. 234

[Washington,] 17 May 1943.

British Plan for the Defeat of Axis Powers in Europe object

The decisive defeat of the Axis Powers in Europe as early as practicable.

section i—invasion of n.w. europe

1. A necessary prerequisite to a re-entry on the Continent across the Channel is the initial softening of German war potential by the intensified combined bomber offensive, the naval blockade and the Russian offensive on the Eastern Front. Since this re-entry will ultimately be necessary, no plan for the defeat of Germany can be drawn up without first examining the essential features of the operation.

2. The essentials for invasion are as follows:—

a. A high degree of air superiority must be achieved during the assault and build-up.

b. Air fields must be captured at an early date.

c. The Coast defences must be sufficiently reduced by the employment of all available means, both before and during the assault.

d. The initial assault must be on a sufficiently large scale and our rate of build-up must compete with that of the enemy.

e. The beach capacity must be sufficient to allow of the subsequent maintenance of the force landed in the first seven days. Sufficient ports must be captured and available for use early.

f. Weather conditions must be suitable.

3. There are two main factors in this problem. These are:—

a. The size of force which can be employed in the assault, which in general is limited by the assault shipping and landing craft available.

b. The relative rate of build-up of our own force, compared to that of the enemy, which can be achieved after the initial assault.

Assault Shipping and Landing Craft Requirements

4. Any assault is likely to meet not less than three divisions in the coastal zone reinforced by up to four divisions after 24 hours. The scale of assault cannot therefore be less than 10 divisions.

The assault shipping and landing craft required for an operation involving a force of this nature, run into large figures owing to the necessity for seven of these divisions being afloat simultaneously.

The scale of craft has been worked out in great detail by the British Planners in conjunction with the Roundup Combined Planners. The number of craft required to cross the Channel is higher than in other parts of the world on account of the need for a quicker rate of build-up and of the higher degree of resistance expected.

5. Of the total force of 10 Divisions, the British can provide 2 assault, and 3 immediate follow-up divisions provided that the Americans allot the following assault shipping and craft:—

L.S.T.2	122	)
L.S.E.	6	)	All required in
L.C.I.(L)	140	)
L.C.T.5 or 6	125	)	U.K. by 1st
L.C.M.3	280	)
Certain maintenance equipment		)	February, 1944.

The above figures are based on the assumption that operations after Husky will take place in the Mediterranean, resulting in additional casualties to landing craft and ships.

6. The American contribution in the assault will amount to two assault divisions and three follow-up divisions. The two assault divisions which must be assault trained before arrival in U.K. must be carried in American assault shipping and American manned craft. The three follow-up divisions will be carried in the first turn-round of the ships and craft employed in the British and American assaults.

7. We understand that it is very doubtful if the total requirements could be found by 1 February 1944—to permit an assault date of 1 April 1944. This would mean either a reduction in the scale of the assault or a rate of build-up too slow to be acceptable.

Rate of Build-Up for Invasion

8. The most favourable area for build-up is that of the North Seine ports—Dieppe to Rouen, in which we estimate that there would be by D plus 7 ten Divisions ashore. Allowing for the build-up of reserves and for ports being put into working order, we estimate that by D plus 90—twenty Divisions would be ashore, and by D plus 125—twenty-five Divisions would be ashore. Thereafter additional ports would have to be used for the maintenance of a force of more than twenty-five Divisions.

9. The maximum maintenance capacity of the ports in the Cotentin peninsula is ten Divisions by D plus 90. Any build-up in this area can only be accomplished if additional ports outside the peninsula are captured.

Enemy Strength

10. The estimated German strength in France and the Low Countries in 1944 is 35 Divisions, of which at least four would be available as a mobile reserve. In addition there are some 100,000 static internal security defence troops. Reinforcing divisions would have to come from Germany or the Eastern Front. Up to ten under-strength divisions might conceivably be available in Germany, but would almost certainly not be available if Turkey were already in the war. Advance units of these might arrive four days after the decision to reinforce and might arrive thereafter in France (but not necessarily in the threatened area) at the rate of six divisions a week. The arrival of reinforcements from Russia must depend on the situation on that front. None could in any case arrive in less than 14 days, after which any available could come at the rate of 2 divisions a week. The defection of Italy would, however, have already reduced the German strength in Russia. Assuming, therefore, that the initial assault is faced by four divisions, our forces would, in the worst case, be faced by eighteen German divisions within the first fortnight, after which mobile reinforcements could only come at the expense of the Russian Front.

11. These rates of reinforcement might be considerably reduced by successful Allied air action, but the extent of this reduction would depend on a number of factors and cannot be assessed until the outline plan is firm.

12. Over and above the fixed defences the minimum Axis garrison which might be in France and the Low Countries, short of a complete withdrawal, is estimated at twenty-two divisions of which three would be in mobile reserve.

13. It is clear that unless Russian action or Allied action elsewhere reduces the enemy potential in France from the figures in paragraph 10 to something approaching those given in paragraph 12, we are unlikely to be able to retain a foothold in France until our rate of buildup gives us superiority over the enemy.

14. Another most important factor, though it cannot be defined as one that is limiting, is the achievement of a high degree of air superiority during the assault and build-up. The Combined Intelligence Staffs have agreed:—

a. If the exploitation of Husky is abandoned, the opposition to cross-Channel operations at 1 May 1944 will be 105 squadrons or 950 combat planes in France and the Low Countries. These might be reinforced immediately by some 10 squadrons, say 100 planes. Within a week 50 additional squadrons, 450 planes, would be concentrated in the area, giving a total, without losses, of 165 squadrons or 1,485 planes. Further reinforcements would depend on Germany’s will to strip the Russian Front.

b. If Italy is out of the war the early opposition to cross-Channel operations will also be 105 squadrons or 950 combat planes. But the enemy’s ability to reinforce this force, will be negligible unless he is prepared to strip the Russian Front.

Deductions

15. To ignore the limitations of a cross-Channel operation outlined above would be to invite the danger of entering on a build-up race in which we could probably never obtain the necessary margin of superiority for success. If, however, the German strength in France can be reduced to the required extent—and we feel confident that it can—without too serious an effect on the availability of our forces in the U.K., successful invasion should be possible with the forces outlined above in the spring or summer of 1944.

16. The Mediterranean commitment which would result from a collapse of Italy would cause a reduction from some 1,480 to 950 aircraft in the potential ability of Germany to resist our cross-Channel operations. Only some unknown and incalculable weakness on the part of Russia could ease this situation for Germany.

Method of Defeating Germany

17. After Husky we must intensify, with every means at our disposal, the process of weakening Germany sufficiently to ensure a successful invasion across the Channel in 1944. To the effect of the intensified bomber offensive, the naval blockade and the Russian war, we must therefore add continued pressure by our combined forces further to stretch the enemy without respite, and if possible win new bases from which to hit him.

Potentialities of the Mediterranean Theatre

18. We have in the Mediterranean powerful and seasoned forces, whose attack is now gaining its full impetus, destroying the enemy and forcing him to give ground. This momentum must be sustained till we have reaped the great advantages in weakening Germany which it promises. Not to do so would be to cast away an unrivalled opportunity of inflicting on Germany a mortal injury and, instead, to give her a chance to parry the final blow and delay her defeat for at least another year.

19. This final blow can only be struck across the Channel; it cannot be delivered from the Mediterranean—but the peculiar nature of the cross-Channel operation sets limits to the weight of this blow.

We therefore strongly hold the belief that to make this blow possible every opportunity must be taken between now and its delivery to exhaust and weaken Germany.

Deception

20. Moreover, apart from weakening the Germans, it is an essential part of this preparation to deceive them as to our intentions. To discontinue operations in the Mediterranean and concentrate our forces in the United Kingdom in a series of moves which could not be concealed, would be to invite them to take appropriate measures to meet what would become an obvious threat.

Immediate Effects of an Italian Collapse

21. After a successful Husky the greatest aid we could give to Russia, and thereby inflict greatest injury which could be done to Germany, would be to tear Italy from the Axis.

22. Seven Italian divisions in France and Corsica, and 32 in the Balkans and the Aegean would lay down their arms and Germany would have to find at least fifteen divisions to replace them or so weaken her hold on the Balkans that she would be in danger of losing control in this vital area—a prospect which she could not tolerate. The loss of some 1,400 Italian aircraft, and the approach of the war towards the southern boundaries of the Reich would cost the extended Luftwaffe at least 450 fighters, half of which would have to be found by improvisation. The enemy’s total air commitments would reduce his ability to reinforce the Western Front to negligible proportions unless he were prepared to strip the Russian Front. The Italian fleet, though admittedly no great menace, contains valuable British heavy units which would be immediately released to engage the Japanese.

23. Apart, therefore, from the moral and political effects of the collapse of Italy, this calamity would immediately prove for Germany a military disaster of the first magnitude.

Subsequent Effects

24. In the West, the occupation of key points in Sardinia and the restoration of Corsica to France would create a threat to southern France which the Germans could not ignore. The Germans would either have to occupy and fight for northern Italy, which they might well be unable to do, or yield air bases which could place 500 bombers within range of a large number of important German targets—notably aircraft factories and oil plants—which cannot be attacked from England, North Africa or Sicily. The safe areas to which the population of western Germany are being evacuated would come under constant threat of air attack, with serious effect on morale. The German air defences would be split and the effectiveness of the air offensive greatly increased. Moreover, the threat of invasion to southern France would be increased, together with the potentialities of diversionary action to coincide with our invasion across the Channel.

25. In Russia the German forces on land and in the air would have to be reduced below the strength that was already inadequate during the winters of 1941/42 and 1942/43.

26. In the East, the Germans would have great difficulty in controlling the Balkans. Sustained at comparatively little cost to the Allies, and supported by air action, up to 300,000 guerillas could harass the enemy’s vulnerable communications, denying him important economic resources in Yugoslavia and Greece, facing him with seriously increasing recalcitrance and throttling his garrisons in Greece to such an extent that it is difficult to see how they could be maintained.

27. Added to this, Ploeşti itself would, for the first time, be brought within range of effective air attack, from Italy; great—possibly vital—damage could be done, and the German air defence commitments would once more be increased. The Roumanians are, moreover, unlikely to show much firmness under air bombardment and only a small proportion of the 38,000 operatives are thought to be Germans.

28. In the Aegean, the Dodecanese would be weakened and might well be taken, and the way opened for Turkey to enter the lists. This event would be a further heavy blow. Its political effect would be immense, Ploeşti would be threatened, together with the eastern Balkan and Black Sea communications, and Germany would be faced with a land front in Thrace which she could only attack if she were to find 7 to 8 more divisions and allot proportionate air squadrons from her already attenuated air forces. We are committed to support Turkey if she is attacked with 48 squadrons and two armoured divisions. These forces must, therefore, be held ready in the Mediterranean against this possibility.

Deduction

29. Collectively, all these strategic prizes might even be decisive. This policy, together with the effects of the Eastern Front and the weighty air offensive, is bound to produce powerful results. The results in our opinion will create a situation which will make the difference between success or failure of a re-entry into northwest Europe in 1944.

section ii—sequence of operations in the mediterranean

The Collapse of Italy

30. The Tunisian disaster has been a severe shock to the Italians. While Husky is being mounted, southern Italy will be bombed, and virtually blockaded at sea. Success in Husky will be a further blow to Italian morale. Whether Italy will collapse at once will depend to a great extent on the degree of support which she receives from Germany and on events on the Eastern Front.

31. If Husky does not bring about a collapse, Italy can be subjected to a heavy scale of air attack. From August onwards, the bomber force from the United Kingdom could develop a scale of attack on the industrial areas concentrated in the North which would create conditions in which the supply and maintenance of the Italian armed forces would become precarious. Concurrently an even heavier attack could be directed from North Africa and Sicily against the South. The combined effects of these attacks might well bring about the collapse of Italy.

32. It is, however, so important to knock Italy out quickly that we cannot rely on air attack alone. We, therefore, consider that limited combined operations should be developed to support the air offensive, maintain the momentum of the onslaught and tip the scales in our favor, as this can be done at reasonable cost and with the resources present on the spot.

33. In the Central Mediterranean, we have the choice of two lines of advance, one northeastwards into the Toe and Heel of Italy to threaten, if necessary, the Rome–Naples area, the other northwestwards to Sardinia and Corsica. An Aegean advance by the Dodecanese would not have an immediate or speedy effect on the collapse of Italy. Operations against the Mainland are more continuous than an attack on Sardinia and are more likely to collapse Italy this autumn. The capture of Sardinia would cost the equivalent of seven divisions. The capture of the Heel of Italy would involve a total of nine divisions. In either case we should employ the bulk of our resources in present Allied air forces in the Mediterranean. The selection of the course to be pursued must await Husky and will turn on such factors as the general air and land situation at the time, German reinforcement, if any, of the objectives, and the morale of the Army and people of Italy.

34. We feel that either of these operations following rapidly upon a successful Husky and in conditions of rising air bombardment would tip the scale in our favor.

Situation After an Italian Collapse

35. The general war weariness and dissatisfaction of all sections of the Italian people will dispose them towards dealing with the Allies. Owing to the heavy commitment imposed by an Italian default, Germany will be forced to cut her unessential commitments and dispose her available forces so as to hold the areas which she considers essential to her security. These are, we consider:

a. The Maritime Alps between France and Italy which she will hold with some two or three divisions.

b. The area east of the River Adige towards the Yugoslav frontier held with some two or three divisions.

36. The fear of air attack on south Germany from airdromes in the Milan and Turin areas, might force the enemy to fight a delaying action on the line Ravenna–Pisa. In this case five low category divisions would be required for internal security in north Italy, twelve divisions for a determined stand on the line Ravennar–Pisa or four divisions for a token stand to delay our progress northward. The provision of these forces would leave the Balkans disastrously weak.

Operations After an Italian Collapse

37. After an Italian collapse we must take full advantage of the situation, to give the maximum further aid to Russia and to facilitate cross-Channel operations in 1944.

38. During the period of confusion we should secure a bridgehead at Durazzo. This would cost four assault brigades and two infantry divisions with one mixed division in reserve in Italy, and might be accomplished with little opposition. We should thus put in a total force of three divisions. This force would activate the guerillas, and we could support it with up to 500 bombers and 300 transport aircraft from the mainland.

39. On an Italian collapse, we should forestall the Germans in the Dodecanese and bring pressure on Turkey to enter the war, and so make available to us the benefits we have already noted, and in particular the use of air bases from which to bomb Ploeşti.

40. Should the Germans decide to remain on the Ravenna–Pisa line, three divisions would be required in the Rome-Naples area to stop German infiltration to the southward. An enemy withdrawal from the Milan–Turin area would leave the air fields open to occupation by us, if we wished to do so. A force of six divisions would be required to secure the air fields against an estimated scale of German attack of 4–6 divisions, but only minor forces would then be required in the Rome–Naples area.

Garrison Commitments

41. We should occupy the Cagliari and Alghero areas of Sardinia and Corsica and occupy, or remain in occupation of, the Trapani, Messina and possibly the Catania areas of Sicily. This commitment would amount to about 15 battalions and 3 brigades.

Summary of Commitments

42. Our proposals for meeting these commitments and our commitments in North Africa are detailed in Appendix “A”.² After they have been met, we estimate that we shall have available in reserve, or for further operations such as an attack on the south of France:

• 5 American Divisions
• 4–7 British Divisions
• 1 French Division

In any event our total commitment on the Italian mainland in the event of a collapse will not exceed 9 divisions.

43. The economic commitment which may have to be shouldered is described in C.C.S. 227.³ This problem will have to be faced in the event of an Italian collapse, whether or not we carry out any further operations in the Mediterranean after Husky .

section iii—effect of mediterranean strategy on the build-up of british and american forces in the united kingdom

Assault Ships and Craft

44. Allowing for casualties at the agreed rate, any of the above courses of action can be carried out with the assault shipping and landing craft (British and American combined) allocated to the Mediterranean Theatre for Husky , together with one or two minor reinforcements of certain specialized British types.

45. Operations in the Mediterranean subsequent to Husky would only reduce the amount of assault shipping; and landing craft for cross-Channel operations in 1944, by the equivalent of 10% of the total personnel and 6% of the total number of vehicles to be landed. The reduction in personnel lift is not serious as the numbers could be ferried from ship to shore.

Thus, in terms of assault shipping and craft, it is evident that the continuance of Mediterranean operations after Husky has comparatively little effect on cross-Channel operations in 1944.

Bolero Build-Up

46. After allowing for a Sickle movement of 380,000 men as well as for the necessary R.N., R.A.F. and Canadian troop movements by 1st April, 1944, the number of U.S. divisions which will be in the U.K. by this elate will be:

a. Assuming no further Mediterranean operation after Husky 20

b. Assuming a continuance of Mediterranean operation after Husky 14½

Of the above divisions under a, two will be in process of disembarkation and two will be linking up with their equipment; but under b, owing to the slower rate of movement to the United Kingdom, only one will be in process of disembarkation and one linking up with its equipment. The total number of U.S. divisions which will, therefore, be available for operations from the U.K. on 1st April 1944, under the two above hypotheses will be:

a. 16 divisions

b. 12½ divisions

47. In this connection, the two examinations of the cargo shipping position just completed by the British and United States Committees on Shipping Availability reveal an apparent deficiency against total requirements, other than post- Husky , of 336 sailings for the rest of the year.

Losses have so far been less than the agreed rate taken as the basis of the calculations. In view of this and the economies that could be effected by the Combined Loading of British imports and U.S. Army supplies in the North Atlantic, this deficiency may be largely eliminated and all calculations in the above paragraph are based on the realization of this hope. It may even happen that the reduction in the programmed Bolero movement shown above due to the additional requirement of some 90 ships for post- Husky operations, may not be fully necessary.

British Forces Available in the U.K.

48. The British forces available in the U.K. for cross-Channel operations by 1st April 1944 amount to 10–14 divisions dependent on whether cannibalization proves necessary or not.

Return of Land Forces From the Mediterranean

49. The size of the cross-Channel assault, as we have already shown, is limited by the number of landing craft that will be available. It would be possible to bring two additional British divisions ex North Africa to U.K. in the first quarter of 1944 without materially affecting the Bolero program as planned for that quarter.

50. It will be seen from Appendix “A” that after the elimination of Italy there will be some ten divisions (British and American) in the Mediterranean available for other employment. Even if we halted in the Mediterranean after Husky , there will be no object in bringing these forces back to U.K. except that they are battle experienced troops, since the availability of landing craft and maintenance limitations will preclude their use in Roundup .

Deduction

51. Thus, if we continue operations in the Mediterranean after Husky , there can be available in the United Kingdom by 1st April 1944 for cross-Channel operations some 22½–26½ divisions, United States and British. These figures could be increased by a further two divisions if it is decided to bring two British divisions back from North Africa (see paragraph 49 above). Even if no post- Husky operations are carried out, the total number of divisions available in the United Kingdom would only be increased by 3½.

Air Forces

52. There are sufficient air forces in the Mediterranean to implement the strategy recommended. Allowing for the bombing of Italy and necessary air striking forces, defensive fighter commitments and air forces for Turkey, we could possibly return to United Kingdom, if offensive amphibious operations in the Mediterranean stopped after Husky , up to the following strength of air forces:

	U.S.		British		Total
Type	Sqns.	A/c	Sqns.	A/c	Sqns.	A/c
Fighter	16	400	9	144	25	544
Fighter/Recce	2	36	2	32	4	68
Light Bomber	12	156	5	80	17	236
P.R.U.	1	13	2	24	3	37
Transport	20	250	-	–	20	258

53. It is at present impossible to say to what extent this would actually increase the air forces available in U.K. in April, 1944, since only a proportion of these units could actually be reconstituted in the line. Additional strength would, however, be given to existing formations by additional reserves of aircraft and personnel.

54. If amphibious operations were continued in the Mediterranean after Husky , the air forces stated in paragraph 52 would have to remain until offensive operations were concluded. There should then still be time to bring back a proportion before April, 1944, but there would be no fighter squadrons to spare, and extra transport aircraft would have to be retained. The retention of fighter squadrons in the Mediterranean would, in addition to the considerations stated in paragraph 53, probably not have a restricting effect on fighter reserves for cross-Channel operations.

section iv—conclusions

55. To concentrate our efforts after the completion of Husky solely upon Roundup is to forego the initiative to the enemy for some months, to adopt a defensive attitude on land and to allow Germany to concentrate for the defense of France and the Low Countries against our invasion.

56. Our plan for the defeat of Germany is therefore:

a. To eliminate Italy by:

(1) Air action and one of the following alternatives:

Either

(2) During or immediately after Husky , a landing in the Reggio area and thereafter continuing operations as soon as possible on the mainland by landing first at Cotrone and then in the Heel.

We estimate that the approximate timings of those operations might be mid-August, 1st September, and mid-October.

Or

(3) During or immediately after Husky a landing in the Reggio area and thereafter continuing operations as soon as possible by a landing in Sardinia followed by one in Corsica.

We estimate that the approximate timing of these operations might be mid-August, mid-October, and mid-November, respectively.

b. To invade northwest Europe with the target date of April 1944.

C. E. Lambe
W. Porter
W. Elliot

Washington, 17th May 1943.

1. Circulated to the Combined Chiefs of Staff on May 17, 1943, under cover of the following note by the Secretaries: “The attached memorandum by the British Joint Planning Staff, prepared after consultation with the U. S. Joint Planners, contains a plan for the defeat of Germany, showing the course of operations and their feasibility[,] accepting the elimination of Italy as a necessary preliminary.” This memorandum was prepared pursuant to a directive of the Combined Chiefs of Staff at their meeting on May 15, 1943; see ante, p. 84. The Combined Chiefs of Staff considered this memorandum together with a companion American memorandum, C.C.S. 235, infra, at their meeting on May 18 and their morning meeting on May 19; see ante, pp. 100 and 112. The consideration by the Combined Chiefs of Staff of these papers resulted in their agreement upon certain resolutions incorporated in C.C.S. 237/1, May 20, 1943, post, p. 281.
2. Not printed. This appendix set forth an estimate of Allied ground force commitments in the Mediterranean area after the elimination of Italy from the war. Of a total of 8 American, 23 British, and 4 French divisions available, 1⅔ British divisions would be in Sicily and the Toe and Heel of Italy, 1 British division would be assigned to the enforcement of the armistice, 3–6 British divisions would be in Central Italy, 1 American division in Sardinia, 1 French division in Corsica, 4⅓ British, 2 American, and 2 French divisions in North Africa and the Levant, 1 British division in the Dodecanese, 3 British divisions in the Durazzo bridgehead, and 2 British divisions for the commitment for Turkey. The remaining 5 American, 4–7 British, and 1 French divisions would be available in the Mediterranean, as reserve and for other employment.
3. Memorandum by the British Chiefs of Staff, May 16, 1943, “Relief and Supplies for Occupied and Liberated Territories”, not printed.