Ferris Intelligence Before Overlord - MOD Intelligence Before Overlord 121 Expeditionary Force (...

Ferris Intelligence Before Overlord

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研究会記録

Intelligence Before Overlord: Knowledge and Assumption in Allied Planning for the

Invasion of Normandy, June 1943-June 1944.

John R.Ferris

Allied intelligence for OVERLORD usually is seen as a success story. That is the

truth-- just not all of it. From June 1943 to June 1944, intelligence revealed German

expectations, understanding and intentions. It showed the enemy was behaving as

OVERLORD assumed, how the allied deception plan, FORTITUDE, was working, and

the weakness of enemy wireless intelligence and aerial reconnaissance. The control of

MI 5, the British security service, over German agents revealed enemy expectations,

and shaped them, by enabling deception. Through Allied codebreaking, ULTRA and

MAGIC showed that German generals and Hitler exaggerated allied forces in Britain by

200% and the initial strength of a seaborne assault by 400%; remained fixed on the Pas

de Calais; but during May paid increasing attention to Normandy and strengthened its

garrison. 1 Intelligence was excellent on great issues yet mediocre about enemy strength

in Normandy on 6 June 1944. Scholars have noted these facts but not explained them.

Studies of intelligence also ignore the layer of assessment which guided planning. In

1994, Alexander Cochrane described intelligence and deception as the “missing

dimension” of studies in OVERLORD. 2 In 2013, studies of planning and intelligence in

An earlier version of this chapter was published as John Ferris, “Intelligence, A Snapshot from 6 June 1944”, in John Buckley (ed), The Normandy Campaign 1944: Sixty Years On, ( London, Routledge, 2006), pp. 185-201. Material in CAB, PREM and WO files may be found in The National Archives, London; the T and RG 165 and 331 series are held at The National Archives and Record Administration, College Park; and the RG 24 series at The National Archives of Canada, Ottawa. The Bernard Montgomery papers are held at The Imperial War Museum, London. 1 MI 14 Weekly Summaries, 15.5.44, 5.6.44, “The OKW and Allied Intentions-Apr 1944”, passim, WO 208/4312; JIC (44) 221 (0) Final, 29.5.44, RG 331/3/131; Hinsley, British Intelligence, Three, II, pp. 49-65, 790.

2 Alexander S. Cochran, “ULTRA, FORTITUDE and D-Day Planning: The Missing Dimension”, in Theodore Wilson (ed), D-Day, 1944, ( Lawrence, Ks, 1994), pp. 63-79, assesses the literature well. The best study of intelligence and OVERLORD, an excellent one, is F.H. Hinsley, E.E. Thomas, C.A.G. Simkins and C.F.G. Ransom, British Intelligence in the Second World War, Its Influence on Strategy and Operations, Volume Three, Part II ( Cambridge University Press, London, 1988). The best account of planning before Normandy, Carlo d’Este, Decision in

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OVERLORD remain mutually exclusive. These problems cannot be solved in 16,000

words, but this paper will examine allied assessments before the invasion of the enemy’s

combat strength and order of battle in France, especially Normandy; and consider why

intelligence success and failure marched hand in hand for OVERLORD, and how far

either mattered. The intelligence record illuminates with unique force, the planning

which led to triumph in Europe, and challenges all conventional narratives of the matter.

The Struggle in Intelligence

OVERLORD involved a struggle between two sides in military rationality,

intelligence and deception. The allies won in every sphere. Military rationality led both

sides to calculate the ideal place for an allied attack would be the Pas de Calais, with its

long and open beaches on the northernmost coast of France, with Normandy second and

anywhere else a distant third; and that an attacker would have great logistical problems.

Thus, the Germans assumed any allied attack must aim immediately to seize a major

port. They spread their bets everywhere, but above all at the Pas de Calais. The allies

put all theirs on Normandy, where they faced a fragment of enemy strength and evaded

most of it; and carried a port in their hands, through the artificial MULBERRY

installations. Again, OVERLORD was the first priority for allied intelligence services,

aided by specialist organs focusing on issues like beach topography. They had good

human sources, excellent imagery and ULTRA and fused them. German sources failed

in coordination and quality. Their spies were controlled by MI 5, their imagery was

spotty, and their wireless interception and codebreaking were mediocre, missing truth

and eating lies. German commanders paid almost as much attention to deception as

allied ones, leaking false news about their strength in defences and divisions, through

many means. This effort had no impact. Conversely, FORTITUDE reinforced German

preconceptions, which the allies predicted by reason, detected by intelligence, and

exploited to victory.

In planning for OVERLORD, military rationality always came first, intelligence

second. Operational decisions were made by middle level planners at Chief of Staff

Supreme Allied Commander Designate ( COSSAC), Supreme Headquarters Allied

Normandy, 50th Anniversary Edition, ( London, 1994), offers good, but brief, accounts of intelligence.


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Expeditionary Force ( SHAEF) and 21 Army Group, by the Supreme Allied

Commander and the chief of 21 Army Group, Dwight Eisenhower and Bernard

Montgomery, and sometimes by the British ( and to a lesser degree, American) Chiefs of

Staff (COS). The key decisions were made purely on the basis of military rationality,

with intelligence irrelevant, by COSSAC in July 1943, to avoid the Pas de Calais and

strike Normandy, tant pis; and by Eisenhower and Montgomery in January 1944, to

double the frontage and strength of the initial attack. Intelligence was secondary even in

the formulation of the initial plan for OVERLORD, though it became central when that

plan was refined and applied between April to June 1944. Most decisions emerged

through the routine interaction of mid level military bureaucrats, by their arguments,

agreements and differences.

This was especially true of intelligence. The British Joint Intelligence

Committee ( JIC ), MI 14, the German branch at the Military Intelligence Division, and

mid level figures in COSSAC, SHAEF and 21 Army Group, dominated estimates.

Specialists handled collection and deception. These officers were able, experienced, and

British. Montgomery and his chief of General Staff Intelligence ( GSI ), Edgar “Bill”

Williams, had served harmoniously for two years. Montgomery’s chief of staff, Freddie

de Guingand, thought Williams “the most able and clear-headed” GSI “I have ever met”.

From January to May, General John Whiteley, an Operations officer trusted by

Eisenhower but not Montgomery, and without experience as an intelligence chief, ran

SHAEF G-2. He was replaced just before D-Day by Ken Strong, Eisenhower’s

intelligence chief in 1943 and first choice for SHAEF G-2.3 MI 14 and JIC reports went

only to top commanders and staff officers; so too, some assessments by SHAEF G-2 and

Williams, though all staff officers and commands to division level received their weekly

estimates. During the planning for OVERLORD, MI 14 and the JIC dominated

analyses of strategic issues and enemy organisation, while Whiteley and Strong

harmonised all sources for their commander, and his forces. After D-Day, SHAEF G-2

dominated intelligence in the west, seizing power from MI 14 and Williams, but until

then it was a fifth wheel. 21 Army Group dominated operational planning, and Williams

the intelligence for it. 3 “Notes taken at a meeting of Army Commanders and their Chiefs of Staff, at HQ 21 Army Group, 7 Jan. 1944”, WO 205/16; Francis de Guingand, Operation Victory , ( Hodder & Stoughton, London, 1947) p 106; Nigel Hamilton, Montgomery, Master of the Battlefield, ( McGraw Hill, New York, 1983), p. 144.

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Tensions there were within intelligence, because of opinion, personality and

tangled lines of command. In October 1943, referring mostly to Ultra, COSSAC

complained it was not receiving “all the essential intelligence available in the War

Office”. Its access to such material steadily rose. By January 1944, SHAEF and 21 Army

Group, and later First United States Army Group (FUSAG), received as much ULTRA

as commanders in Italy, and more JIC material. 4 Again, in February, the senior

operations officer at SHAEF thought Williams was addressing “a problem of a much

larger nature than any with which he had been previously faced”. 5 Yet they also pulled

together. Williams told Whitely, his senior in hierarchy but junior in experience, “I do

not want to be preaching a contrary doctrine to yours, for I feel there is real value in an

agreed text. If we are to be wrong, let’s all be wrong together. At least then our

Commanders will not have had muddled counsel. You will remember the loss of

confidence in the Middle East caused by the internicene but public disputes between the

“I” people which helped nobody, least of all the disputants”. 6 These officers avoided

disputes, but agreed texts were hard to find, because authorities confronted a situation

up to twelve months away. They made and argued over predictions as much as

assessments; all strove for accuracy, each understood its limits. COSSAC’s July 1943

plan for OVERLORD noted,

As it is impossible to forecast with any accuracy the number and location of

German formations in reserve in 1944, while, on the other hand, the forces

available to us have been laid down, an attempt has been made in this paper to

determine the wisest employment of our own forces and then to determine the

maximum number of German formations which they can reasonably overcome.

Apart from the air situation, which is an over-riding factor, the practicability of

this plan will depend principally on the number, effectiveness and availability of

German divisions present in France and the Low Countries in relation to our

own capabilities. 7

4 Minutes of meeting on “organisation of Intelligence for C.O.S.S.A.C.”, 3.10.43, WO 171/19; Whitefoord to Chief of Staff, 19.1.44, SHAEF/19BX/INT (SP), RG 331/1/58.

5 West to Whiteley, 17.2.44, RG 331/12/9. 6 RG 331/12/9, Williams to Whiteley, 2.2.44 7 PREM 3/342/2/8, C.O.S. (43) 416 (O), “Operation ‘Overlord’, Report and Appreciation”, 30.7.43, p. 4.


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Commanders and planners thought less about Germany’s current strength in France,

than how it would meet amphibious attack, of its power relative to allied forces in recent

battles, its uncommitted forces across Europe and their speed of deployment. When

making these decisions, allied planners used whatever intelligence they had. It served

them well. Yet between the time plans were made and executed, much might change;

and many key points did not lie simply in the sphere of intelligence—like how good the

enemy would be, and how it would prepare its defences and counter attack. The value of

intelligence was defined by its ability to support planning, which in turn was based on

predictions of power and military rationality.

This process produced characteristics in preparations for Normandy.

Intelligence and planning never were combined effectively on paper, only in the minds of

commanders. The planning applied on 6 June 1944 rested on old estimates, not current

ones. Most planning was done by April, reflecting estimates of that era; Williams’

weekly assessment of 4 June reached generals only as their units were at sea. Even

more, these estimates and plans recognised a wide range of possibilities. Assessment

had to be fluid, because enemy strength and intentions were changing, and rapidly. The

allies originally planned to attack on 1 May. Had they done so, Normandy would have

had barely 50% its garrison of 6 June, which in turn might have received the extra few

divisions needed to force the postponement of OVERLORD or to defeat the operation,

had the attack waited until 1 July. Enemy intentions and capabilities were not distinct

matters, but fused—what Germany would do, was what it could do. If the enemy

guessed right, it could defeat OVERLORD, or deter it. Meanwhile, a dynamic tension

emerged between worst-case and better-case assessments. Worst-case logic has a bad

reputation, because in open-ended circumstances it causes timidity and costs

opportunity. Yet in OVERLORD, uncertainty on basic issues and the need to control

risks were unusually high. Worst cases were hard to avoid, and took an odd role in

planning. Caution was the better part of error, doubly so because planners and

commanders recognised they were applying worst-case logic, tried to minimise its

impact, and sought to understand how Germans ( not allies) would act. The tension

between worst case logic and attempts to control it, in one wave after another, marked

all planning for OVERLORD.

At the highest of levels, the War Office, JIC and COS took care to avoid

presenting worst case estimates to the British Prime Minister, Winston Churchill,

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presumably so not to provoke an effort to cancel the operation. They emphasized that

German air and land forces exceeded the conditions which COSSAC originally had

defined for success, but also were less formidable than their numbers indicated, while

allied strength in the assault had risen more. 8 Otherwise, higher layers of authority

outlined worst cases, primarily for the sake of form; which subordinates received, but

regarded as beyond their concerns; with the key cogs in the system remaining free to

assess and act as they chose. These worst cases had little effect at the time, but remain

embedded in evidence, ready to trap unwary scholars. They shape conventional ideas

about key aspects of planning before OVERLORD. Thus, Montgomery’s celebrated

briefing of generals at St. Paul’s School on 15 May 1944, treated as the touchstone for

expectations before 6 June 1944, made points he knew were misleading. He rated

German strength more than his own intelligence agency did. He credited them with 22

assault divisions in France, ten Panzer and 12 Field Infantry. He forecast that between

D + 6 and D + 8, 24 divisions would surround the bridgehead, including 10 Field

Infantry divisions, and also 10 Panzer divisions launching a “full blooded counter attack”.

9 These figures matched the very worst case assessments of MI 14, SHAEF and the JIC.

They were twice the level of the COSSAC conditions, and also of the figures reckoned by

Williams, which governed planning in 21st Army Group. Presumably Montgomery

delivered this overestimate because these were the figures defined from above: to use

them caused no problems, to use anything else would raise questions. They aided

showmanship, and spurred preparations, making generals sweat more over training,

only to find operations easier than expected. They gave him even greater credit for

victory, when it occurred. None the less, this assessment does not reflect Montgomery’s

expectations of German numbers, nor his planning, though his prediction at St. Paul’s of

what German forces would seek to do between D + 1 and D + 8 was prescient and honest.

That numerical overestimate, and the inadvertent but widespread misinterpretation of

the meaning of the map that 21 Army Group displayed about the expansion of the

bridgehead between D Day and D + 90, which was intended for logistical purposes but

understood to predict a steady advance, meant that this briefing misled its audience

about key issues, and later commentators as well.

8 Hinsley, British Intelligence, Three, II, p. 713. 9 Nigel Hamilton, Master of the Battlefield, Monty’s War Years, 1942-1944, ( New York, McGraw-Hill), pp 582-9.


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The Allied Assessment of German Forces

COSSAC assumed that the quality of enemy units would remain constant and

the enemy would use them as well as it could. COSSAC’s July 1943 assessment of the

air aspect of OVERLORD was a classic statement of worst-case planning:

The following estimates and appreciations are based on factual intelligence and

consider the scale of enemy air effort possible under ideal conditions, not taking

into account any effect that the present Allied air offensive may have on the

G.A.F.’s fighting value in the future...Furthermore, the rates of reinforcement

are those of which the enemy is physically capable, considering the scale of

efficiency of his organization as a whole, and do not take into account the effects

of any counter-action by Allied forces. The scale of effort envisaged assumes also

that the enemy would concentrate the maximum strength possible even at the

expense of adequate defence elsewhere. 10

In this instance, worst-case logic was accurate: during June 1944 the Luftwaffe did

throw most of its remaining aircraft across Europe into the battle of Normandy. Had

that logic been applied to land forces, planners would have had to abandon

OVERLORD; here, the worst case centred on the nature and the number of “full-

strength first quality divisions” Germany could use against OVERLORD. In July 1943,

COSSAC concluded that OVERLORD had a “reasonable chance of success” only if

German forces and defences in Normandy, its reserves in the west and all aircraft

deployable there, did not rise above the level of 30 July 1943, including 12 “full-strength

first quality divisions” in France; if no more than three such formations joined the local

forces of three infantry divisions on D-Day, five by D + 2 and nine by D+ 8; and if no

more than 15 good formations moved in from other theatres by D + 60. 11 These

calculations approximate the level of German forces actually in Normandy between D-

Day and D +8. Their effect in combat confirms the accuracy of COSSAC’s predictions.

Soon, however, the quality of German forces sagged, and were seen to be

sagging. In July 1943, COSSAC calculated Germany had 1740 first-line aircraft in the 10 PREM 3/342/8, C.O.S. (43) 416 (O), “Operation ‘Overlord’, Report and Appreciation”, 30.7.43,

pp. 1, 69 11 PREM 3/342/8, C.O.S. (43) 416 (O), “Operation ‘Overlord’, Report and Appreciation”, 30.7.43,

pp. 25, passim

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west, but its key concern was the “steady rise” in fighter strength, which must be

“checked and reduced” before invasion. Air intelligence estimated that between 1

January and 1 August 1943, German first-line strength in fighters had grown by 245

aircraft, to 1340 ( or 2260, counting second-line reserves), and that in the west from 305

to 600 machines. 12 In February 1944, planners expected to confront 1650 first-line

German aircraft on D + 1, perhaps soon joined by 950 more but, like COSSAC, they

noted the Luftwaffe’s lack of “appreciable depth” and inability to sustain losses. Soon,

SHAEF thought German fighter pilots “vastly inferior in quality” to American ones. By

May, the British COS agreed that the Luftwaffe’s strength exceeded July 1943 levels, by

5250 to 4870 aircraft, including 2700 fighters versus 2175 ( first-line and all reserves),

but this was irrelevant: its decline in quality, production and reserves changed the

meaning of the numbers. 13 These figures still distorted German air strength— the

Luftwaffe did throw most of its fighters into OVERLORD, but they numbered barely

1300—yet that problem was minor. All planners abandoned the worst case about the

Luftwaffe save Trafford Leigh-Mallory, commander of the Allied Expeditionary Air

Force; this division provoked needless debate over any part of OVERLORD related to air

support, crippled the use of airborne forces and made decisions imperfect, but not

seriously so. Worst case logic ruled the equation at air and sea, but led to little worse

than wasted effort. Given the circumstances confronted by allied air and naval forces—

with forces to spare, and superiority over the enemy in vital areas, where risks could not

be run—worst case logic was the best means to define the level of insurance. For a quick

and single premium, the cost was cheap.

The story was different regarding assessments of the German army. As

COSSAC wrote, the issue was not so much “the precise number” of enemy divisions as

their “effectiveness”: if they “are below strength or of low morale, or if German ability to

12 CCS 309, 15.8.43, PREM 3/333/15. 13 Fourth Draft, 30.1.44, “Neptune, Initial Joint Plan”, WO 205/15, 1.2.44, Neptune, Initial Joint

Plan, WO 171/126; SHAEF Weekly Intelligence Review, No 6, Part II, RG 165/79/2566; PREM 3/342/10, COS to Churchill, 23.5.44, “Opposition to Overlord”; F.H. Hinsley, E.E. Thomas, C.A.G. Simkins and C.F.G. Ransom, British Intelligence in the Second World War, Its Influence on Strategy and Operations, Volume Three, Part II ( Cambridge University Press, London, 1988), pp. 35, 103-125. The discrepancies between these figures occur because allied estimates of what German air strength would be on 31 July 1943 changed, while two different issues were being assessed, the “initial establishment” of first-line units, and total Luftwaffe strength, including second-line reserves.


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move them is reduced, we can face and defeat a proportionately larger number”. 14 When

assessing the balance between the allied and German build-ups at Normandy, a major

figure in the Operations section at SHAEF, General H.R. Bull, noted, we are tempted to

look on the enemy forces as fully-equipped, fully-trained, battle experienced 1940

divisions, instead of regarding them as 1944 divisions, diluted by foreign elements, and

in several cases far from being up to strength or effectively trained... I feel that the

whole difficulty in estimating the enemy’s course of action lies in appreciating what real

strength we are up against as opposed to theoretical strength. This, I think, must be

evaluated in the monthly estimate of the rate of reinforcement, to avoid giving us the

one-sided impression a purely logistical calculation is apt to do. 15

Great problems emerged in understanding the enemy’s real strength. Several good

sources, ULTRA above all but also agents in France and imagery, kept an extraordinary

grip on the enemy’s order of battle. From August 1943 to June 1944, the number of

German formations in France constantly shifted, as did Allied estimates of them Until

April, when SHAEF thought its information “unsatisfactory”, they included several

German formations which were not in that theatre. 16 Estimates were filled with

speculation about the value and name of formations. Given the nature of planning and

the situation, and German security and deception, these problems were hard to avoid

and errors often cancelled each other out. At any time, allied intelligence was good on

the identifications, numbers and locations of formations in, entering or leaving the

theatre, and almost perfect on these matters in the weeks before D-Day. It gave

commanders accurate information they trusted, reinforcing their faith that enemy

strength still was within the COSSAC conditions. 17

Yet, simply to identify the quantity of divisions was not enough; their quality

was of equal importance. Virtually every division in France was rebuilding, some

starting in early 1944 from just 10%-25% their establishment of equipment and trained

soldiers; to determine how good they would be on the day, one needed to know not just

their current strength, but how far and fast each would improve. Two types of

formations proved especially hard to assess. “Training” divisions, infantry and armoured,

14 PREM 3/342/8, “Overlord”, p. 10. 15 331/29A/119, Bull, AC of S, G-3, to AC of S, G-2, SHAEF/17100/12/Ops, 24.2.44 16 SHAEF to AGWAR, S-50558, 21.4.44, RG 331/1/114. 17 Material on these matters is contained in RG 165/79/2566, RG 331/29A/119, RG 331/12/9, RG

331/1/114.RG 331/1/59, WO 208/4312 and WO 171/102.

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had an uncertain value: though usually that title described their function, to provide

drafts to other formations, rarely they did serve in combat, and over time their rating

could rise. Meanwhile, the allies ranked German infantry divisions either as Field

Infantry, capable of independent assault in mobile operations, or Lower Establishment

( LE), defensive formations ranging from poor to decent in quality, about half having just

two instead of three regiments, including some “Ost” battalions ( with German officers

and ex-Soviet soldiers). The allies recognized another, and worse, category, “Static”

divisions, but believed none were in the west. In any case, they had mixed success in

determining the real strength of most German infantry, and also of the best enemy

forces.

ULTRA illuminated the manpower and training of Panzer, Panzer Grenadier

and Paratroop formations, but not their equipment. ULTRA and the Combined Service

Document and Interrogation Centre ( CSDIC ), which collected and assessed material

from these two sources, offered good material about LE divisions. 18 The allies’ grasp of

these formations was sound, no easy task, yet not perfect. Conversely, intelligence on

Field Infantry was lacking, and estimates of their value were arbitrary and erroneous.

These problems were fundamental to assessment, producing worst case assessments

which drove far into the heart of planning, though irrelevant on the battlefield,

fortunately. The JIC’s last full estimate of German strength in France identified 14

Field Infantry divisions. It overrated by 33% the manpower of four of them, and that of

eight others and most LE formations by 10%. The JIC slightly underrated the quality of

the best infantry in France, 3 Paratroop Division, which also had 33% more soldiers

than expected—18,000 men, twice the strength of the average infantry division in

France. With that exception, every other so-called Field Infantry formation had just

50%-66% the manpower of average ones of 1939. 19 Only one of them, 5 Paratroop

Division, had the strength even of what in 1943 the British termed “ 2nd Quality

Infantry Divisions” ( 12,000 soldiers), while four were much weaker than “ Defensive

18 RG 165/179/660, C.S.D.I.C. ( U.K.) S.I.R.s No 110, 115, 117, 119, 236, 256, 277, 340; RG

165/179/659, C.S.D.I.C. ( U.K.) No 293 19 Compare RG 331/3/131, JIC (44) 215 (0) 25.4.44, to the figures in David Westwood, “The

German Army in France 6 June 1944”, paper presented to the conference on Normandy, Wolverhampton University, July 2004.


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Infantry Divisions” ( 10,000 men). 20 Manpower was only one indicator of combat value,

but a central one, and the allies knew German infantry placed increasing reliance on

organic firepower. All told, allied intelligence distorted the combat quality of German

infantry—in reality, only one Field Infantry division stood in France, Third Paratroop.

The rest were just slightly better than usual LE formations, while many of the latter

were far worse than even that title would indicate, Static divisions. Fewer offensive

divisions fought at Normandy than expected, in part because the Germans had fewer of

them in France than the allies estimated. This worst case logic distorted assessments

about the effect of FORTITUDE at the time, and afterward, because observers could see

no other reason for Germany to retain forces on the Pas de Calais after D-Day, and

exaggerated their value, especially of the 18 LE divisions left on the Pas de Calais after

I July.

A little intelligence and knowledge of standard enemy practices provided a fair,

if overstated, account of the number of flak and anti-aircraft guns which could be

deployed at Normandy, calculated around 1300. 21 This approach failed in another

sphere. In its greatest technical failure before D-Day, allied intelligence did not know

the number of tanks in Panzer Divisions, or in France, and knew it did not. This failure

stemmed from limits in ULTRA, which did worse in tank counting than ever since 1941,

because changes in the way German formations reported their tank strengths stymied

the codebreakers at Bletchley Park. The latter solved messages, but could not

understand their meaning. Bletchley began to overcome these problems on D-Day itself,

but all prior calculations rested on guesses. 22 These took many forms. Allied planners

knew the number, location and manpower of armoured formations in France, but errors

over tank strength crippled views of their combat value. The Germans had fewer tanks

than allied intelligence feared, but more than allied planners assumed. On 6 April 1944,

ULTRA showed that the German commander in chief in the west, Gerd von Rundstedt,

aimed to make his three Panzer training divisions combat worthy as quickly as possible.

Williams, thinking this “a desperate improvisation”, never took them seriously. He did

not formally assess their value but at most, he seemingly thought each of these divisions

might provide a weak but combat worthy battlegroup, of regimental or brigade strength.

20 Appendix ‘E’, COSSAC (43) 4, RG 331/3/124 21 JIC (44), 215 (0), 25.5.44, RG 331/3/128. 22 Ralph Bennett, Ultra in the West.

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Before von Rundstedt’s message, the JIC rated these formations and all non-divisional

armour as together matching two divisions in strength, in which calculation training

units were a minor factor. In early April, conversely, MI 14 expected each Panzer

training division to be fully operational by D-Day. By 30 April, the JIC rated them as

equal to two operational divisions; by 25 May it thought only “elements” of each “are at

present capable of employment in an offensive role”. In fact, they did not fight until the

last days of Normandy, with mediocre quality. 23 Yet throughout this period, these

formations always were counted at face value on the books, crediting the enemy with

three ( or 43% ) more Panzer/Panzer Grenadier Divisions in France than the seven

which were there on 6 June. Hard intelligence on these formations was scanty— one

training division had no Panther battalion and was short of motor transport; 2 SS

Panzer and 17 SS Panzer Grenadier lacked motor transport while 12 SS Panzer did not;

“slight evidence” suggested 21 Panzer had two tank regiments ( in fact, it had a weak

regiment). 24 The absence of intelligence drove the allies to predict German tank

strength by their understanding of enemy establishments. This approach caused

overestimates, as the allies understood these establishments no more than the Germans

followed them.

MI 14, thinking it knew from ULTRA the formal establishment of Panthers in

Panzer Divisions but ignorant of their real strength, assumed all but training divisions

had a full strength battalion with 81 Panthers, unless it had proof to the contrary,

reversing the analytical process used to determine the number of Panzer Divisions in

France.25 MI 14 and SHAEF’s grasp of the strength of Tigers and Panthers in non-

divisional units was accurate enough ( estimated as 135 Tigers and 283/320 Panthers,

against in reality 102 and 250 on 6 June, or the armoured elements of three Panzer

divisions). They were, however, wrong on important elements of German organisation.

They did not know 21st Panzer Division lacked its Panther battalion, while those of two

armoured formations and a training one were at 50%--66% the strength assumed by the

allies; and thought four assault gun battalions were additional non-divisional units,

rather than being part of formations. Predictions of strength derived from

establishments could take many forms. If one added the figures for non-divisional 23 Hinsley, British Intelligence, Three, II, pp. 72-77,814. 24 JIC (44) 215 (0) 25.5.44, RG 331/3/131. 25 “Allotment of Panthers to Armoured Divisions in the West”, MI14 /Apprec/8/44, 18.5.44, WO

208/4312; JIC (44) 215 (0) 25.5.44, RG 331/3/131.


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armour and assault guns, to seven Panzer divisions on what was taken to be full

establishment, plus one Panther regiment above establishment, and three training

divisions weak in Panthers, one had 1830 armoured fighting vehicles ( AFVs)—or 1560,

if the training divisions were entirely removed from that figure.

In reality, even the low ball projections exaggerated the problem. On 6 June

1944, in France the Germans had 1891 AFVs , including 179 captured ones, 39 Mark

IIIs ( for command purposes), 758 Mark IVs, 102 Tigers, 655 Panthers and 158 assault

guns. Of these, 26% had limited combat value—captured tanks, Mark IIIs, and the 253

Mark IVs and 40 Panthers in training divisions—leaving 1420 battleworthy AFVs. In all

fairness, German strength was hard to determine. Allied estimates of it varied wildly,

and many were grossly wrong. Just before D-Day, Third US Army thought the Germans

had 1750 to 2600 tanks. FUSAG, relying on estimates of enemy strength from February,

assumed each of the seven Panzer and Panzer Grenadier Division it thought were in the

theatre would have what it took to be a full complement of 160 tanks, but ignored non-

divisional forces and training divisions, for a total of 1120. MI 14 , the JIC and SHAEF

thought the Germans had 800-850 Panthers alone, though they could not offer “a

reliable estimate”, and “may possibly” have a total of 3000 tanks—159% above the true

strength. 26 The figure of 1120 came from knowledge of average German complements;

so too that of 3000, added to every piece of certain and uncertain information, including

aircraft sightings of empty flat cars, commonly used to carry Panthers on trains, moving

eastward toward the Rhine, indicating they had done so in an unobserved inward trip.

At the strategic level, imagery on train movements created more mysteries then it

solved.

Allied estimates of German tank strength were wrong, but in many ways, not

one. Calculations of enemy armour were all over the map. On 6 June, FUSAG and 21

Army Group overestimated this strength and SHAEF underestimated that to be found

in Normandy. They led units to underrate the armour before them at H hour, but to

overrate that which could arrive there by H + 24. The problem was uncertainty, rather

26 After Action Report Third U.S. Army, I August 1944-1 May 1945, ( Scholarly Resources), Reel

One, Chapter 2, p 10; “Operation Neptune”, FUSAG, 20.5.44, First United States Army Group, Report of Operations, 23 October 1943-1 August 1944, Reel Two, Book Two ( Scholarly Resources). “Allotment of Panthers to Armoured Divisions in the West”, MI14 /Apprec/8/44, 18.5.44, WO 208/4312; JIC (44), 215 (0), 25.5.44, RG 331/3/128.

132

than fixed error. It had little impact at the strategic level, since the issue was academic

and the mistakes cancelled each other out: but it did cause problems at the tactical level.

The Allies Assess the German Reaction to Invasion

The issue was not just the enemy's total and real strength, but how much of it

could intervene in the battle, and when. This matter was central to planning for

OVERLORD. Allied planners were split on this point, with almost everyone grossly

overestimating the problem; fortunately, Williams came close to truth, and 21 Army

Group acted on his assessments.

The allies were uncertain about the enemy’s true combat strength in France and

its likely one at the front on the day of battle, and those which would follow. In October

1943, COSSAC thought that if the attack were launched immediately with good security,

given the number of “full strength, first quality” German divisions in France, assessed

around 10, their weak establishments and the effects of wastage and interference with

their movements, on D Day the allies would confront local forces and two Panzer

Divisions ( with the real strength of one); and by D + 4, three Panzer Divisions and four

infantry divisions ( with the real strength of 1.5 and three, respectively). 27 This

assessment may have been accurate, but this situation was changing; the questions

being, how much and how fast? In February 1944, SHAEF and 21st Army Group agreed

that “when the flag falls”, the chief German commanders, Erwin Rommel and von

Rundstedt, would have 20 divisions able to attack in mobile operations ( roughly 12

armoured or mechanised, and 8 Field Infantry). 28 The quantity of divisions assessed at

this quality rose toward 20, and passed it by late May, in a confusing flurry of estimates,

often contradictory in details. MI 14 and the British COS expected the Germans to have

17-21 divisions able to conduct mobile warfare, ( equaling 12-16 “full strength and first

quality” formations in value). The JIC predicted 16 to 27 good ones, though between 20

and 25 May, without explanation, its estimate of the number of Field Infantry divisions

fell from 16 to 14. On 15 April, SHAEF G-2 thought the enemy had eighteen offensive

divisions in hand ( 8 Panzer/Panzer Grenadier and 10 Field Infantry) and 28 ( 10

27 “Operation ‘Overlord”, Calculation of Enemy Rates of Reinforcement-Conditions of –1 October

1943”, WO 171/19. 28 Whiteley to West, 3.3.44, RG 331/12/9.


133

armoured and 17 infantry) on 2 June; both cases included the three training Panzer

Divisions. Beyond this, allied planners rightly agreed that non-divisional units held a

divisions’ worth of Tiger tanks and two of Panthers. 29 By the absolute worst case, in

France the Germans might have the equivalent of 14 armoured divisions, with 3000

tanks, and 17 Field Infantry divisions, on D Day—far above COSSAC’s conditions and

enough to abort the invasion. Against these calculations, planners knew these numbers

meant less than they seemed—SHAEF G-2 emphasised “the old question of the goods in

the shop window and the empty shelves behind, without which no appreciation of enemy

capabilities would be complete” 30--and doubted all of these forces would strike the

beachhead. They did not expect their worst case, neither could they ignore it, nor was

their better case pleasant, especially because of the way they assumed the enemy

machine would function.

In Tunisia, Sicily and Italy, German commanders responded aggressively and

immediately to seaborne invasion. At Salerno and Anzio, the Germans succeeded in

sealing allied forces on the beachhead. One had to expect similar efforts in Normandy,

which the enemy publicly predicted would occur. In a press interview, which Williams

distributed to his readers, von Rundstedt warned that his coastal defenceshave depth

and cannot be outflanked. In their rear there exists a system of field fortifications and

strongpoints. Mining, swamping and flooding obstacles and tank walls are so manifold

that they could not even have been dreamt of by those who build the Maginot Line.

Water obstacles along the beach for enemy landing craft and a wide mined belt on the

beach would make a landing difficult even in its initial phase before the enemy had even

been able to gain a footing. Against expected large-scale landings by airborne forces in

the rear, measures have been taken long ago, but they must be kept confidential. In my

sector there is no possibility of side-stepping or retreat. The coast line and the deeply

echeloned fortifications can be held to the last. Thus it is possible that landed enemy

forces will be split up, because they must fight for every single fortification. Numerous

vast reserves, above all Panzer and mechanised divisions, are kept in readiness in

29 Chiefs to Staff to Churchill, 23.5.44, PREM 3/342/10; JIC (44), 215 (0), 25.5.44, RG 331/3/128;

SHAEF Weekly Intelligence Summaries, Nos 6, 7, 9 and 10, 29.4.44, 6.5.44, 20.5.44, 27.5.44, RG 165/79/2566; SHAEF to AGWAR, S-50365, 15.4.44, S-53053, 2.6.44, RG 331/1/114; 21.5.44, “Statement as to the PZ, PZ Gren and Field Divisions in the west in terms of full strength first class divisions:”, WO 208/4312.

30 SHAEF Weekly Intelligence Summary, No 6, 29.4.44, RG 165/79/2566

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groups in such a way that within a few hours they could make a powerful counter-attack.

The Germans do not indulge in the tired Maginot spirit. We conduct our fighting by

making use of strong fortifications and of other means which, for quite obvious reasons, I

shall not divulge. 31

Some of these statements reflected von Rundstedt’s campaign of deception-- after the

war, he claimed to have believed that the Atlantic Wall was an “unmitigated fake”

which any attack quickly would penetrate—but the comments on counter-attack did

reveal how he expected to fight, until he was frustrated by other commanders, German

and allied. 32 These comments reached the highest levels of allied command, and

reinforced their greatest area of uncertainty. This knowledge first divided allied

planning, and then drove it to adopt measures which overcame the problem, and the

enemy. It overcame a hard case by treating it as a worst case.

The allies had little intelligence on how German command would meet an

attack. A fair amount of material from ULTRA, captured documents and prisoners

showed that divisions in France responded to emergencies with unpleasant speed. Units

sometimes were on the move 30 minutes after receiving orders, regularly within 90; as

Williams emphasised, “troop trains are kept standing by in important divisional areas”

while “time-tables are prepared”; probably, several entrained divisions could move at

any one time from Russia to France in 7-10 days. 33 This evidence showed the best the

machine could do when it worked well, but not whether it would do so. The allies neither

understood nor pretended to understand German command. They knew personal

politics might affect decisions—Whitefoord doubted that Rommel and von Rundstedt

“would work harmoniously, as their outlooks are so different”, Montgomery that

“quarrels might arise between the two of them”—but did not bank on it. 34 Allied

analysts overestimated the rationality and autonomy of generals in France and

underrated their rivalries. They knew Hitler hated to abandon ground but

underestimated his interference. The allies assumed all enemy armour would be

31 “GSI 21 Army Group, Weekly Review, No. 2”, 20.2.44, WO 171/102. 32 Interrogation of General Gerd von Rundstedt, 4-14, 1.2.46, WO 205/1020 33 Sherrington to Fass, 230/4/42, 3.8.43, memorandum by FUSAG G-2, 8.12.43, “German

Movement of Reinforcements in the West”, passim, RG 331/12/9; 21 Army Group Weekly Intelligence Report No 9, 17.1.44, WO 171/102

34 COSSAC “Intelligence Review, 17.12.43, RG 331/12/13; Brief by Montgomery, “Brief summary of Operation OVERLORD as affecting the Army”, 7.4.44, BH Montgomery Papers, No 74, Imperial War Museum.


135

commanded by Armies, throwing all their forces immediately at the beachhead, and by

Army Groups or OKW, acting after thorough and rapid thought. They read German

reactions from Rommel, his characteristics and his proclamations of smashing invasion

on the beaches. These assumptions were reasonable, unavoidable, but wrong, and

shaped by cultural and military ethnocentrism, and mirror imaging. MI 14 described

German command as a rational bureaucracy, rather like that of the allies. Hitler was

Supreme Commander, but his power was neither defined nor discussed. The chief

soldier at OKW, General Keitel was “in effect, a Minister of Defence”. Its General Staff

handled “the general conduct of the war, and the main outlines of strategy, and is

responsible for operational planning”. Its role was “not exactly known”, butthe procedure

is however believed to be as follows. Once an operation has been decided upon, the

General Staff of the Armed Forces prepares plans in a broad sense. It then selects a

commander to carry out the plan. He is chosen with special regard to his experiences

and qualifications, and may belong to any of the services. He is, except probably in the

case of a large-scale campaign, allowed to chose his own force and his own subordinate

commanders. He defines his wishes to the General Staff of the Armed Forces, which

pass on his requirements to the Service ministries, leaving them to work out the

detailed plans in conjunction with the commander and his staff. 35The Germans would

have done better at Normandy to act that way, but they did not. The allies expected

German command at least to match their own; they were not.

Allied planners tried not to exaggerate this matter, but still they did. In late

1943, COSSAC’s Operations Branch noted “the Intelligence Branch have determined to

show the worst possible picture in order that they may be on safe ground”. The

GERMAN forces move with mechanical precision, without hesitation, without error of

destination, and without interference to the right locations where they arrive, deploy

and attack at the right time on the right plan. Even admitting that the nearer reserves

will know of and have practiced their counter attack role, does that means that it can be

carried out as if every allied move had been foreseen months before, or that the later

reserves will be equally conversant with the terrain and the situation? If so, we may as

35 “The Supreme Command of the German Armed Forces ( Oberkommando der Wehrmacht-

O.K.W.)”, 12.5.44, MI14/g/Apprec/4/44, WO 208/4312.

136

well call off ‘OVERLORD” and try an operation which we can keep secret from the

enemy more successfully. 36

In January 1944, General Morgan called for an estimate of the German response based

on “what I may call a rather more military, rather than mathematical, angle. Up till

now, we have always made a comparison of two sums in simple addition, ours and theirs.

I think we should now interest ourselves in forming some estimate of the way in which

the enemy will handle the resources that have been so carefully deduced by

mathematical means as being available to him, at various times in relation to D day”. 37

Planners agreed about how the Germans would react. Complete surprise was

unlikely for OVERLORD—impossible for an attack much after first light. Assault at

night or dawn might provide “a limited degree of tactical surprise”, but even so, several

hours earlier the enemy would know attack on north-west France, and probably

Normandy, was imminent, by finding convoys at sea before dusk. 38 In January,

Eisenhower noted the “extreme importance of the enemy not having even 48 hours

warning of the actual points of assault”. 39 Planners were more demanding and

optimistic. They expected the enemy to realise Normandy would be attacked four hours

before the assault ( H - 4) , perhaps more; to remain uncertain for some time whether

this was the only assault, or if its target was Le Havre or Cherbourg, the major ports on

either side of the Normandy peninsula; but quickly to regard it as a major threat. Then

trouble would start, the only questions being, how much and how soon? The answer was

measured in hours, and divisions.

Staff at COSSAC, forced to work with a small beachhead and rating enemy

quality high, always doubted the attackers could survive the planning condition of a

36 illegible minutes by G-3 Ops Div, 26.10.43, COSSAC/00/6/15/Ops, RG 331/29A/119 37 RG 331/1/58, Morgan to ACOS G-2, 4.1.44. 38 Appendix B to NJC 5 ( Final), 14.12.43, WO 205/12. This version abandoned the view of the

preceding draft that an attack at night or dawn might gain tactical surprise, perhaps even preventing enemy moves from occurring before first light, when allied troops “”’touch down’” and the enemy “can estimate the strength of our convoys”, Appendix “B” to NJC (4) Final, 14.12.43, WO 205/12. In fact, the latter situation did occur on D-Day, because of the decision to land in bad weather, combined with German incompetence. Though initial warning of the allied attack came just after midnight on 6 June, largely through radar reports of ships at sea and news of allied airborne landings, local German commanders did not begin to act for almost ten hours afterward, and took almost as long to execute these actions, while decisions by senior commanders about the release of reserves were even worse.

39 Memorandum by COS for Churchill, 5.2.44, PREM 3/345/4.


137

counter-attack by five divisions on D + 2.40 That reaction was universal, leading senior

authorities to favour an expanded beachhead, new commanders and revised

assessments. In February 1944, 21 Army Group planners expected local German forces

to react instantly at H – 4, but hoped those elsewhere would not. Williams wrote, “In my

view the decision to go the whole hog and risk everything on turning us out of the

NEPTUNE area cannot be taken earlier than evening D + 2. Until then whether

immediately available reserves are going to be enough for the task cannot be evident.

After that it must be neck or nothing, and he may then be prepared, if forced, to sell out

of the no longer vital areas of the West”. Most mechanised divisions should reach the

front by D + 4. Williams envisaged the “horrifying prospect” of a “full-blooded counter-

attack” on D + 6 by all mechanised forces in France plus whatever infantry was in the

area, which he then rated at 12 and three divisions. 41 At SHAEF, Bull thought the

enemy “will react almost automatically and according to pre-arranged plan with his

Army Reserves and very promptly with Army Group Reserves close behind, accepting

only the necessary delay required for preparing his estimate of the situation”. Whiteley

too accepted Williams views about what would occur at H-4 and D + 2. He thought local

forces would react immediately, while all mechanised divisions in the west would reach

Normandy by D + 7. 42 By April, Whiteley assumed “the enemy counter attack forces”,

based at Brest, Normandy, Le Havre and the Pas de Calais, “laying back from the

coastal area, will have perfected and rehearsed plans to deal with the various situations

likely to arise. These divisions, therefore, will move swiftly to the threatened point once

orders have been given committing them to the battle”. Between D + 1 and D + 3, local

forces would attack Normandy, where all other reserves would arrive by D + 7, and

decision would begin. 43 The final edition of “Operation Neptune” expected a “piecemeal

counter-attack initially... at points where the assault is making good progress”, rather

than “a co-ordinated counter-attack”. Divisions “arriving later will be employed in a

coordinated counter-attack according to preconceived plans. The crisis of ground battle is

40 COSSAC G-2, 12.1.44, COSSAC/3DX/INT, Timing of Enemy Counter-Attacks Against Neptune

Bridgehead”, passim, RG 331/12/9. 41 RG 331/12/9, Williams to Whiteley, 2.2.44; 21 A Gp/CO/INT/1101/4/15, “Delay of Enemy

Strategic Reserves”, 21 A Gp/00/74/39/G ( Plans), 21.2.44, “Neptune, Employment of Armoured Forces”, WO 205/19B.

42 Bull to D/AC of S, 5.2.44, G-2 Div, 5.2.44, “Examination of Enemy Rates of Reinforcement”, RG 29A/119; SHAEF/17100/1/Ops, by Betts, 3.5.44, WO 171/19.

43 G-2 Estimate of the Enemy Build-Up Against Operation “OVERLORD”, 5.4.44, RG 331/1/59

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estimated between D plus 3 and D plus 6”. 44 By these estimates and Montgomery’s

initial planning, the Germans would have numerical parity against the 10 1/3 allied

infantry or airborne divisions and five armoured brigades ashore by D + 4, and the 17

and five by D + 8, and afterward. 45 So to overcome this problem, the allies boosted their

build-up between D + 2 ( 12 divisions) and D + 5 ( 15 divisions), in both cases joined by

five armoured brigades; but after D + 8, the old balance returned.

When combined, the concepts of enemy strength and behaviour produced an

alarming image of opposition to OVERLORD. Planners expected to engage whatever

forces were in Normandy, estimated initially at three or four infantry divisions, but

which reached six ( including four LE formations) and a parachute regiment in the days

before D-Day. Just before the invasion, good intelligence from many sources on these

reinforcements led planners to consider abandoning the attack on the Cotentin

peninsula and almost 30% of their assault frontage, and forced commanders radically to

reconfigure preparations there. 46 In January 1944, even after doubling the strength and

frontage of the landing, Montgomery noted “The theoretical rate of enemy reinforcement

compares unfavourably with our own build-up, and there is nothing to prevent him from

concentrating all his forces against the central assault sector, on which we are primarily

dependent for maintenance. If he succeeded in defeating us in this sector, it is unlikely

that our other landings could survive”. 47 Eisenhower feared that by “about the ‘10th

day’...pressure against OVERLORD might become dangerously strong”. 48 His chief of

staff, Walter Bedell Smith, thought “the buffer of German divisions confronting us

across the channel is just now approaching the absolute maximum we can handle”. 49

That buffer, alas, continued to swell. In February, planners estimated that by D + 6,

nine to 12 mechanised divisions would strike the beachhead; in April, American

44 20.5.44, HQ First US Army, “Operation Neptune”; p. 122, First United States Army, Report of

Operations, 20 October 1943-1 August 1944, SR, Reel One, Book Two. 45 “Build Up”, note from Montgomery to Churchill, 23.1.44, PREM 3/342/7. 46 Bradley to Montgomery 26.5.44, “Memorandum for; General Montgomery”, 381 (C), WO 205/5;

20th SCAEF meeting, 29.5.44, WO 205/12; memorandum by Bull for SHAEF COS, 26.5.44, “Implications of the Reported Enemy Reinforcement of the COTENTIN PENINSULA”, RG 331/1/76.

47 “Notes for the Commander-in-Chief for the Supreme Commander’s Meeting”, 21.1.44, WO 205/12, “Notes for the Commander-in-Chief’s Meeting with the Supreme Commander”, 21.1.44, WO 205/16.

48 Dill to COS, telegram FMD 93, 14.1.44, PREM 3/342/1. 49 D.K.R. Crosswell, Beetle, The Life of General Walter Bedell Smith, ( University Press of

Kentucky, Lexington, Ky., 2010), pp. 586.


139

intelligence in Washington predicted a strength of 7 Panzer and 10 field infantry and LE

divisions by that stage. Just before the invasion, estimates of this strength between D +

6 / D + 8 surged; the JIC predicted 16-17 divisions and SHAEF G-2, 15 ( along with

whatever remained of forces there on D-Day). 50 Counting the local garrison, SHAEF’s

estimates of enemy divisions around the beachhead by D + 8 grew from 13 to 22—above

COSSAC’s conditions, even when accounting for quality. Meanwhile, planners assumed

one infantry division per day would enter the battle from D + 8, either because they

advanced ( in the worst case, causing stalemate) or the allies did ( in the best case;

driving deep, with continuous pressure everywhere, “by alternate thrusts toward the

EAST and towards the SOUTH-WEST, we should be able to retain the initiative, reap

the benefit of interior lines, and keep the enemy from moving his reserves from one

flank to the other”). 51 This picture soon darkened. In May, SHAEF and American forces

accepted that by D + 25, the allies would be engaging or have destroyed 11-12 Panzer

and 17-26 infantry divisions, with some 20 more remaining on the Biscay, Belgian and

Mediterranean coasts. 52 Bedell Smith told another officer that “he had no misgivings

about our troops getting ashore, but gave me the alarming prediction that our chances of

holding the bridgehead, particularly after the Germans get their build-up, is only fifty-

fifty”. 53 This dark picture, however, was irrelevant, because it disagreed with the only

text which counted, at the time that mattered.

21 Army Group Solves the Problem.

As OVERLORD approached, Williams’ analyses differed from those of SHAEF,

MI 14 and the JIC. 54 They all noted the interaction between fronts, especially Russia

and France, but this issue was more central to his analyses, which were pointed,

50 JIC to SHAEF, 6.4.44, RG 331/12/9; passim. 51 21 Army Group to FUSAG, 1 US Army and 2 British Army, 21 A Gp/20651/19/G ( Plans),

13.5.44, “Appreciation of the Relative Build-Up Between Allied and Axis Forces-Operation ‘OVERLORD’”, WO 171/203.

52 After Action Report Third U.S. Army, I August 1944-1 May 1945, Reel One, Third United States Army Outline Plan, Operation Overlord, nd; SHAEF G-2 Estimate, No 2, 14.5.44, RG 331/12/9; SHAEF Intelligence Staff, Appreciation No. 3, Part II, German Conduct of the Campaign in the West”, SHAEF/CIS/102/INT, 22.4.44, WO 171/19.

53 Harry C. Butcher, My Three Years with Eisenhower, ( New York, Simon and Schuster, 1946), p. 538.

54 William’s GSI 21 Army Group, Weekly Reviews, may be found in WO 171/102.

140

optimistic, consistent and focused on what enemy offensive capabilities would ( not,

might ) be from D-Day to D + 60. On 13 February, he told his readers, “The needs of the

West await the decision of the East...German resources are stretched on all fronts and

there is little to spare”. On 2 April, “the enemy is courting further and further a

deepening disaster in the East to retain a good chance in the West, a strange gamble

militarily, made intelligible politically by the prospect of a compromise peace if the

Western decision bore fruit; in short, more and more Stalingrads in the hope of one

Dunkirk”. In February, Williams thought Germany could redeploy 15 good divisions to

France from other theatres by D + 60. That number soon fell to 13 and in April, after

devastating German losses in Ukraine, to six, with perhaps two more from Italy. These

losses, Williams thought, would force the Germans to send replacements to Russia, and

so slow the rebuilding of formations in France, where on D-Day Germany would have

only 12 to 16 offensive divisions, most likely closer to 12. On 9 April, these numbers fell

by five. A Field Infantry division, much non-divisional armour and two crack formations,

9 and 10 SS Panzer Divisions, went from France to the east, as did spare forces in other

theatres. Williams crowed, “The great decision has had to be taken... The Red Army has

forced a revision of the proposed strategy of 1944; the West has lost its priority and its

insulation ...in their doughty turn, the Russians make ‘Overlord’ more possible”. He also

held (correctly), that two Panzer Divisions previously thought to be in France were not

there, though the Germans might use their training Panzer Divisions in combat, with

uncertain effect. For Williams, as with every analyst, mid April was the most optimistic

period before D-Day, when German strength was inadequate against OVERLORD, and

its ability to grow was uncertain. From then until 6 June, like every analyst, Williams

estimate of German strength in France rose. Still, he held that on D-Day Germany

would have fewer offensive divisions than the 20 he and SHAEF had forecast in

February, probably only 12, perhaps less, and be able to transfer only half as many

formations to France after D-Day as had then been expected, or less—probably far less.

Every analyst had a worst case and a better one. Williams’s cases were more

optimistic than those at SHAEF and MI 14— SHAEF planners, heirs to COSSAC’s

tendencies toward worst case planning, thought his far too much so. 55 His worst case

was their best, because of personality and function. Williams liked clear analysis and

55 West to Whiteley, 17.2.44, passim , RG 331/12/9.


141

bold prediction; so did his chief consumer. Whiteley preferred bean counting and

narrative; under Strong, SHAEF assessments became like those of Williams, though

often their views differed. MI 14 and the JIC reached conclusions about out of theatre

transfers like Williams’, sometimes before he expressed them, but their views were more

academic-- mutable and sensitive to new or uncertain information. They, and Whiteley,

were responsible to authorities who could make only one decision—to unleash

OVERLORD or postpone it. Their job was to assess the range in which enemy strength

would fall and report if it might be too high; legitimately, they could change their minds

overnight without explanation, or define the worst case--just for the record, or to show

what might go wrong. Williams did the same when he stood in similar shoes, when

outlining German tank strength on the day for his subordinates in 21 Army Group. In

the month before D-Day, the JIC’s worst case assessment of the number of German

divisions able to reach France from other fronts by D + 60, switched from 15, to 13, to 18,

and then toward eight, as the German front in Italy collapsed; just before the assault it

warned that 3000 German tanks and 27 offensive divisions might be in France. 56 If

taken literally, such predictions would have forced decision makers to consider

postponing OVERLORD and constantly to change their plans; but they were not so

intended. In March, the COS asked whether JIC reports meant that enemy strength

was above the COSSAC conditions. The JIC’s Secretary replied that its estimates of out

of area transfers did not mean what they said—they were ”very conservative” and

“highly unlikely” to occur. SHAEF, “have not, as far as I know, ever in so many words

stated that they are prepared to meet” the reported rise in German strength in France,

but it had done so “by implication”--because it continued to plan for an invasion despite

knowing the JIC’s views! 57 The JIC explicitly presented its figures of 3000 tanks and 13

divisions transferred by D + 60 as being the very worst possible case. Williams could not

adopt such an attitude, because his job was to assess intelligence to aid the planning of

operations which would occur; nor did he think these views were right. He selected the

most optimistic of best and worst cases. His predictions were close enough to work.

On 6 June, the Normandy garrison was stronger than any analyst predicted

before 25 May —well past the level COSSAC thought acceptable, measured in divisions. 56 JIC (44) 66 (0), 1.3.44, RG 331/1/114; JIC ( 44) 127 ( 0 ) Final, 3.4.44. XXX; JIC (44) 127 (0)

( FINAL), 3.3.44, RG 331/3/126; JIC (44) 188 (0) Final, 13.4.44, JIC (44) 198 (0) (Final), 13.5.44, JIC (44) 210 (0) (Final), 20.5.44, JIC (44) 215 (0), 25.5.44, RG 331/3/128.

57 Hinsley, British Intelligence, Three, II, p. 71b

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That indicator, however, was misleading, because German divisions had fewer units

than in 1943, diluted with “Ost” troops. Measured by a constant indicator, purely

German units, on 6 June that garrison included 30 infantry battalions ( three divisions

and one regiment on a 1943 scale), one parachute and one panzer grenadier regiment,

with the rest of 21 Panzer Division nearby. In numerical terms, this garrison was one

division above the COSSAC conditions for success on D-Day, but perhaps slightly below

them in qualitative terms. In any case, this rise in German strength did not produce

failure, but it did prevent success. German reinforcements were smaller and slower than

any allied analyst dared predict, though close to the level Williams hoped, and within

the COSSAC conditions. By D + 12 ( 18 June), the first wave of five Panzer/Panzer

Grenadier divisions, three infantry divisions ( including 3 Paratroop) and elements from

two more reached Normandy. Compared to SHAEF’s predictions of 3 June, this was

66% the expected level of reinforcements in armoured formations and 40% in infantry,

producing a total of 60% the mechanised divisions ( six) and 65% the infantry ( nine

divisions and three battlegroups ) at the front. Even more, two of these Panzer Divisions

were not yet in action. By D + 25 ( 1 July), the second wave, of another infantry division,

elements of four others and two Panzer divisions, reached the front. Compared to

SHAEF’s predictions of 3 June, this was 100% the expected gains in armoured

formations but only 20% of the infantry, producing at the front 80% the Panzer/Panzer

Grenadier Divisions ( eight) and 47% the infantry—much less, given their losses ( 10

divisions, and elements from another seven). (In both cases, battlegroups are treated as

33% of a division, an overstatement which perhaps balances 3 Paratroops’ superiority

over any other German division). On these issues, Williams was much more accurate

than any other analyst, and good by any standard. All allied analysts, however, were

wrong on two major matters, which together involved almost 33% of the German tanks

deployed to Normandy. On 6 June, 19% of German tanks in France ( including 40% of

its Panthers and Tigers) were in non-divisional units. Planners never forecast their

arrival, which transformed the capabilities of any formation they joined, and so the

fighting. Roughly half these tanks reached the front by D + 12, the rest by D + 25.

Meanwhile, no analyst predicted the main German transfer to France, the return from

Poland of 9 and 10 SS Panzer Divisions, with 15% the total tank strength in France on 6

June. Thus, the Germans transferred as many elite forces to France from outside it as

the allies ever feared, but only one other infantry division. These transfers were smaller


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than allied analysts had predicted before 25 May, but larger than they had hoped just

before D-Day.

Compared to what did happen, Williams’ assessments of what would happen

were good, but not perfect. He slightly underrated enemy capabilities, which all other

analysts significantly exaggerated. Allied planning followed his estimates, gaining from

their strengths and losing from their flaws, which stemmed less from intelligence per se

than its relationship to planning. The allies could use strategic intelligence until the

moment landing craft were launched, but just in one sense, to postpone OVERLORD.

Tactical intelligence could be incorporated up to 48 hours before, but only in matters like

fire plans on the beaches. From mid May, however, operations and operational

intelligence were prisoners of prior planning. The naval commander forbade any change

to plans for D-Day involving seaborne landings or supply. Except on the Cotentin

peninsula, where in late May airborne attacks were changed to reflect enemy

redeployments, the planning applied on D-Day was made between February and April.

It also rested on William’s intelligence estimates from that period, the most optimistic

reading of evidence from the most optimistic time, which no one, including himself,

entirely accepted on 5 June. These plans assumed the enemy would have fewer

formations at Normandy between D + 8 and D + 20 than SHAEF expected and more

than 21 Army Group did; and that the Normandy garrison would be weaker than every

analyst thought it was.

Williams rightly predicted the value of German infantry and armoured divisions,

and their strength in formations around the beachhead by D + 8 and D + 20. When

these plans were formulated between February and April, he was more right on those

issues than anyone else; and so too when they began to be executed. Yet his estimates on

the day of execution were different from those during the days of planning. Moreover,

because he accurately assessed the numbers of combat worthy formations in France, his

estimates were upset more by unexpected matters, like the rise in the Normandy

garrison just before OVERLORD, or the arrival of 9 and 10 SS Panzer Divisions, or the

impact of non-divisional armour, than were those of other analysts, with fat free from

their worst cases to cover underestimates elsewhere. The allies paid for Williams’

accuracy in assessment by underestimating the enemy in important particulars, though

the gains were worth the costs. Again, by 5 June Williams had a remarkably good

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picture of the enemy, which, alas, could not help units on 6 June, though it guided

actions in coming days. So too, like other planners at 21 Army Group, he was more

accurate about numbers of enemy formations than the situation they would produce

once battle was joined. His estimates and their planning attempted precisely to gauge

the nature of many variables and their interactions and combine them into one whole.

He and they were surprisingly accurate, but imperfect, and the battle took a different

form than they had expected. This situation should not be surprising.

OVERLORD and the Limits to Intelligence

Normandy was a hard operation. We tend to forget that fact because it was done

so well. The Allies, forced to launch a seaborne assault against heavily defended

positions, could not leave the beachhead until their strength had built up, by which time

the Wehrmacht had surrounded them in a powerful ring, at a time when the balance of

military power on land had swung away from the attacker, defensive systems became

elaborate and killing zones deeper and deadlier, especially along the narrow fronts of the

west. OVERLORD, the most complex operation of the Second World War, faced

interlocking problems that required precise and accurate solutions. Either inaccuracy or

imprecision could hamper operations or wreck them; yet the more precise planning was,

the less accurate it could be, because chance must strike like a tsunami. Planners for

OVERLORD controlled just one part of a dynamic and reciprocal system. They

determined what to do on the basis of guesses about what the enemy would do, and the

interaction between their wills and actions and chance.

21 Army Group understood these facts. It played to the odds and understood

them. What went right outweighs what went wrong, and avoided the worst of outcomes;

but still some mixed ones occurred, because of the way 21 Army Group and the allies

made decisions. Some aspects of OVERLORD were planned in a tight and centralised

way—in particular, anything to do with seaborne issues, like beach assault and

logistics—others not. OVERLORD, after all, was defined by a staff without power or

responsibility. Its land component was refined by another staff parachuted in five

months before the attack; and it was fought by armies of several nationalities, each with

its own command, doctrine, training and preparations on stream. This produced a

strikingly loose approach to intelligence, planning and training. Estimates of German


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armoured strength were imprecise, contradictory, and left that way—every authority

was free to believe what it wished; so too, views of enemy strength between D Day and D

+ 25. 21 Army Group followed Williams, while American forces were more pessimistic.

In May 1944, FUSAG’s version of NEPTUNE used for intelligence an estimate of 10

February 1944, so old that many of the formations it listed no longer were in the west,

while others known to be there were not mentioned. The Third US Army gave its forces

an assessment based on SHAEF’s views of 17 April. 58 That every command had its own

estimates created some confusion on 6 June. Above all, it blinded generals and units to

tactical realities. In preparing for OVERLORD, the allies faced three circumstances,

each requiring distinct training: beach assault, attrition, and mobile war. Everyone

expected and trained for the best case, quick breakthrough leading to mobile war, and

ignored the prospect of having to fight through the bocage, rectangular fields enclosed by

hedgerows, which seemed pessimistic and old fashioned. This issue fell through that gap

in intelligence, planning and training. No allied commander matched Montgomery in

the ability to fight this kind of battle, but even his plans did not play to this strength.

Where British and Canadian units had a tribal understanding of how to fight such a

battle, American ones did not, and their commanders ignored these weaknesses. This

shaped a key phenomenon of the first six weeks of the battle of Normandy: the failure of

the American army.

Meanwhile, the allied ability to gain what usually is the easiest material to

find, tactical intelligence, was constrained. In the 50 days before 6 June, eight dedicated

squadrons conducted 735 photographic reconnaissance (PR) missions in north west

France, including seven overflights of the main beachhead up to 4,000 yards inland, and

detailed coverage of beach gradients and enemy forces. Yet the allies could not focus

these resources on the real target for fear of tipping their hand—as it was, the Luftwaffe

drew dangerously accurate predictions of allied intentions from analysis of allied

reconnaissance flights. The allies aimed to fly two imagery missions elsewhere for every

one flown over Normandy. When free to concentrate on the real target, this work was far

more effective—from 6 June 1944, 380 PR sorties were flown over Normandy each day.

58 First United States Army, Report of Operations, 20 October 1943-1 August 1944, SR, Reel One,

Book One, 20.5.44, HQ First US Army, “Operation Neptune”; After Action Report Third U.S. Army, I August 1944-1 May 1945, Reel One, Third United States Army Outline Plan, Operation Overlord, nd.

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59 Had this effort been possible in the weeks before OVERLORD, perhaps it would have

overcome the problems in tactical intelligence. So too, in February 1944, the allies

ceased trying to take prisoners or conduct seaborne reconnaissance in Normandy,

though they understood this would cripple the collection of tactical information. The only

such mission run thereafter, aimed to examine the nature of outer beach defences, was

conducted at the Pas de Calais, for security reasons and with effect—though the

Germans detected the mission, this information reinforced OKW’s predisposition to fear

for that region. 60 The allies hoped to make up for the damage done to tactical

intelligence by interrogating prisoners taken in Italy who previously had been in

Normandy, with mixed success. 61 Allied forces in Italy did not capture prisoners from

any division presently in Normandy, though some based there in 1943 did illuminate old

procedures, while other captives gave excellent and recent accounts of defences and their

defenders in Brittany, Belgium and the Netherlands. 62 CSDIC provided useful

background to assessments of defences in Normandy, but nothing concrete; imagery

provided many facts, which guided planners and commanders, and the maps issued to

assault units. Still, much was missed.

These circumstances and constraints prevented good intelligence services from

discovering basic points. Errors that normally would be inexcusable, were unavoidable.

Few things should be easier in intelligence than to determine the strength and defences

in a tactical sector one plans to attack; but this proved beyond the grasp of services

which otherwise achieved marvels. Though prior planning and the initial assault rested

on a good picture of the topography and defences on the beaches, the allies missed

important details: and at H hour, a prior failure to locate individual guns could have

deadly costs. In particular, the allies were unsure of the deployment of two of the

enemy’s seven divisions in Normandy, its best formations there, standing precisely at

places the allies must attack on D-Day. 352 Infantry Division, a formation with full

59 “Operation ‘Neptune”, Joint Commanders-in-Chief Memorandum No. 7, Air Reconnaissance-

Requirements and Resources”, NJC/00/74/6, 15.4.44, WO 205/15. 60 Hinsley, et.al., British Intelligence, Three, II, p. 89; Helmut Heiber and David Glantz eds),

Hitler and his Generals, Military Conferences 1942-1945,The First Complete Stenographic Record of the Military Situation Conferences, from Stalingrad to Berlin, ( Now York, 2003), pp. 434.

61 3rd Joint Commanders in Chief meeting, 22.12.43, WO 205/12; SHAEF/45BX/1/INT, 9.2.44, SHAEF/17/225/Ops, 12.2.44, RG 331/12/9

62 RG 165/179/660, C.S.D.I.C. ( U.K.) S.I.R No 130, 132, 136; RG 165/179/659, C.S.D.I.C. ( U.K.), No 160, 213, 260.


147

strength and some combat veterans, raised by 150% the strength of the garrison on Gold

and Omaha beaches and made them formidable, while 21 Panzer placed its anti-tank

units and half its infantry between the Orne River and Caen, key British and Canadian

targets on D-Day, with its armour in easy reach behind. This position was well suited to

its task and its enemy-- the Germans deployed their forces as well in Normandy, as they

did badly in France. Allied intelligence looked hard and objectively for information on

these forces, and Williams suspected, but could not prove, they might be near their true

locations. His last report before D-Day, of 4 June, warned that 352 Division might be

where it really was, while noting 21 Panzer was unlocated, but thought to be entirely

outside the assault area, from which it likely would advance toward Caen as a whole

around H + 12. He gave worst case, but sound, estimates of the amount of German

armour his forces would meet on D-Day, 240 tanks and 40 assault guns ( only 10 % off

the real strength of the two armoured formations in the sector, 12 SS and 21 Panzer).

Second Army intelligence, conversely, warned its units to expect immediate local

counterattacks by some armour, while between H + 12--H + 24, they might encounter

540 tanks ( more than twice the real strength of those formations), and perhaps 160

more from 17 SS Panzer Grenadier Division ( which in fact had only 42 assault guns). 63

Second Army correctly warned some armour might be met before Caen, and much more

there, but it grossly distorted that strength--one of the greatest examples of worst case

logic before OVERLORD. Here, as in similar instances with the JIC or SHAEF, the aim

probably was to state the absolute worst case, so to make people think about the

problem in advance, to show the limits to bad news, and for the record, rather than to

state one's true belief. After all, if Second Army was right, all that could be done was

cancel OVERLORD--the allies could not possibly defeat a force so much larger than that

defined in the COSSAC conditions.

Williams’ last estimate did not reach divisional commanders before the attack,

but that of Second Army was known to all unit commanders. They ignored it, for reasons

which remain unclear. Units essentially seem to have treated that issue as academic--

above their pay scale. The mere process of hitting the beaches and forming up to

advance were difficult and time consuming. Units seem to have preferred to focus on

known problems, and largely ignored anything which would happen later, because such

63 Hinsley, et.al., British Intelligence, Three, II, pp 847-51.

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matters obviously were unpredictable, and their superiors were uncertain about them.

Thus, British units assumed they would drive straight off the beaches and first meet

enemy forces around Caen, in an encounter battle, possibly with Germans attacking

British positions, rather than charging themselves into enemy units deployed in

defensive systems. They expected to meet substantial enemy armour after Caen, but

little before it. Nothing but a clear warning the enemy already controlled the approaches

to Caen could have affected their attitudes; which Williams would have done had he

been able to; but he could not. Even such a warning merely could have saved some lives,

tanks and, above all, confidence in high command; the real problem was that the

Germans held Caen, not the fact this surprised the allies. These failures in the

intelligence cost lives, but not the battle. Even had they known the truth, the allies

would have had to try to take Caen on 6-7 June, and largely in the same way—

otherwise they would have been condemned for passivity. In any case, they crushed the

only German counterattacks launched during the landing, and ensured ultimate victory.

So too, certain knowledge of the location of 352 Division could have done nothing to stem

the slaughter at Omaha beach. These intelligence failures were indicative, but not

influential

More significant was a muted version of an old problem. In the CRUSADER

operations during 1941, British intelligence was precise in classic ways—99% accurate

on the enemy’s order of battle and numbers of tanks-- and let its forces time their attack

with optimum effect. Yet they were grossly wrong on basic matters, like the quality of

enemy forces and weapons relative to their own. 64 Meanwhile, an extremely precise

plan, relying on intelligence collapsed, as did the Eighth Army. Poor training negated

good intelligence. British intelligence was better before CRUSADER than OVERLORD,

and integrated as much into planning; but by 1944, allied armies, plans and

commanders were better. Even so, before OVERLORD the allies misinterpreted the

relationship between terrain and tactics. Planners and units assumed that once ashore,

they quickly would enter the rolling country inland from Normandy, and fight mobile

battles. Even an able “tactical study of the terrain correlated with the latest Intelligence

estimates of enemy capabilities” of 7 May, which discussed fighting in circumstances

64 John Ferris, "The 'Usual Source': Signals Intelligence and Planning for the Crusader Offensive,

1941", In David Alverez (ed), Allied and Axis, Signals Intelligence during the Second World War, (London, Frank Cass, 1999), pp. 84-118.


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like and roughly on the line of 28 June 1944, was over optimistic. It defined that

territory as “not an easy one for forces to advance through rapidly in the face of

determined resistance, but it will likewise be most difficult for the enemy to prevent a

slow and steady advance by infiltration”. It was “difficult to judge” whether the bocage

would better suit attacker or defender; tactics for the matter “should be given

considerable study by formations to be employed therein”. In perhaps the greatest

failure in allied planning before the invasion, this advice was not followed. 65 More

broadly, allied planners did not realise they would be fighting a battle of attrition in

terrain well suited to the defender, and did not train for it. They knew Panthers, Tigers

and 88 mm anti-tank guns were formidable, not that they would be attacking the largest

force to space densities in these weapons the Germans ever managed on the defence, in

terrain well suited to their strengths and allied weaknesses. Through these gaps in

tactical intelligence flowed tragedies.

Again, intelligence enabled effective planning for the beach assault, and the first

days of the fight. It could not do so for subsequent operations, because too much was

unpredictable. 21 Army Group ordered Canadian forces to plan for a breakout toward

Le Havre and the channel ports on D +20, on the assumption that the bridgehead had

reached the point it roughly did around 28 July—8 August, D + 62 to D + 74, during the

Cobra offensive. Canadian forces, on a line from Argentan to the coast at Houlcourt,

allegedly would confront a few infantry divisions, undefined in number and implicitly

low in quality: “the enemy’s principal anxiety will be to defeat or contain the forces

further SOUTH-WEST”, driving on the Loire river and Brittany. These assumptions

anticipated Hitler’s orders around 28-30 July, but not the disposition of German forces.

The commander of First Canadian Army, H.D.G. Crerar, retorted that these

assessments rested on a “very sketchy” basis. “While I am without authoritative

information on this matter, my personal judgment leads me to somewhat contradictory

conclusions”, which represented the disposition of German forces around 28 July, but

not their actions, or Hitler’s orders: the enemy would “treat the threat to the LOIRE and

BRITTANY ports as of secondary importance, and consequently… counter attack with

maximum forces, and as soon as possible, the left sector, or Eastern flank, of the Allied

bridgehead”. Crerar’s staff should assess “this alternative problem ( the defence by First

65 21 A Gp/20651/55/G ( Plans), 7.5.44, “Appreciation of Possible Development of Operations to

Secure a Lodgement Area, Operation Overlord”, WO 205/118

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Canadian Army of the Eastern flank of the Allied bridgehead against heavy and

determined German counterattack)”. When Williams was asked to assess this debate, he

concluded that much is pretty obviously guesswork at this stage and my guess is that

the Canadians should be prepared to face 2-3 Pz plus 7-8 infantry divs: depending on the

success of 2 British Army. Therefore it seems essential to me that the Canadian Army

chooses ground vital at once to the retention of their sector and as a diving-board for

“AXEHEAD”. I am afraid that General Crerar will find these comments very unhelpful.

That is, First Canadian Army, with four infantry and two armoured divisions,

should plan an assault leading to breakthrough, while absorbing singlehandedly a full

blooded counter-attack by half the German Army at Normandy! That assessment

echoed the Canadian position at the Falaise Gap. Instead, 21 Army Group told Crerar to

plan an assault which also could handle one large counter-attack, but not more, though

“with the information now available, the possibility cannot be excluded”. 66 Not

surprisingly, these plans had little value when Canadian and Polish forces assaulted the

remnants of five panzer and ten infantry divisions on both the defense, and attack,

around Argentan and Falaise between 8--21 August. These commanders and planners

were competent and informed men, fairly accurate in their net assessment of

capabilities and intentions, but intelligence simply could not provide the surety needed

to produce a plan able to survive first contact with the enemy. Their discussions

illustrate that problem.

Intelligence and Deception

Intelligence also shaped a struggle in deception. It showed in real time what the

Germans expected and perceived, enabling adjustments to allied behaviour ( both

positive and negative) so to minimize the chance of inconvenient actions. That the allies

conducted deception before OVERLORD is famous; that Germans did so, is not. Von

Rundstedt, however, later claimed to have developed “ a huge deception programme”,

aimed to mislead the allies about his forces, including “intensive propaganda about the

invincibility of the Atlantic Wall”, the laying of dummy minefields, and systematic

66 21 Army Group 00/316/1/G Plans, 20.3.44, WO 171/126; Memorandum by Crerar for C in C

and 21 Army Group, CPS/1-6-4, 14.4.44, passim, NAC, RG 24/C 17/13607; Appreciation by Williams, “Axehead”, 30.4.44, and de Guingand to Mann, 24.4.44, WO 205/5C.


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efforts to fool authorities across France into exaggerating the strength of German forces,

so spurring false rumours to London. He passed false maps of defences “to the Allies by

means of German agents in Paris and Switzerland”, and exaggerated statements of his

forces to the Japanese ambassador at Vichy, so “to lull both him and his government

into a sense of security as to the strength of German forces in the west”. 67 Von

Rundstedt’s claims are plausible. Germany often conducted such practices, and wireless

deception. It attempted to simulate the presence of Luftwaffe forces in France during

1941, as part of the cover for Operation Barbarossa, though British intelligence

penetrated this effort, so finding a clue to German intentions. 68 Von Rundstedt’s chief of

staff, General Gunther Blumentritt, confirmed his claims, while other generals and

soldiers described efforts to exaggerate the presence of panzer and infantry divisions in

France during 1943-44. 69 The effect of these efforts is hard to trace. British intelligence

never used ( and probably never received) the maps allegedly shipped through

Switzerland. Perhaps it did pick up some of the rumours circulating through France,

which might explain certain errors about German order of battle in early 1944, but if so,

the skill and sources of British intelligence overcame that threat, without detecting the

danger, at little cost to planning.

The material allegedly leaked to the Japanese embassy in Vichy raises greater

problems. That information was intended to deceive Germany’s ally, not its enemies: von

Rundstedt could not have known this material might reach his foes, because they read

Japanese diplomatic traffic. Nor does any allied intelligence acquired from Japanese

authorities in Vichy fit von Rundstedt’s descriptions. His statement, however, suggests

that Germans sought to deceive other Japanese authorities who inspected the defences

in France in 1943-44, like General Oshima Hiroshi, the Japanese ambassador, and

Admiral Kojima Hideo, the naval attaché, to Germany. Reports from these men rank

high within the intelligence available for planning in OVERLORD. When critically

assessed, they reflect either a mistaken overestimate of Nazi power or else, and more 67 RG 165/179/649, CSDIC UK, G.R.G.G. 326 (0), C in C West and the Allied Invasion Plan, 1943-

1944; Interrogation of General Gerd von Rundstedt, 4-14, 1.2.46, WO 205/1020. 68 Brieftagebuch Haifisch I u. II, H.Gr.D. 85566, T 311/34, NARA; Air Historical Branch, The

Second World War, 1939-1945, The Royal Air Force, Air Ministry Intelligence Part II: Chapter 6, paragraph 58, undated; Hut Three History, Section III, Development as a Research Organization ( Spring 1940-Autumn 1942), HW 3/104.

69 RG 165/179/659, CSDIC ( UK) , S.I.R. 520. “285 I.D, ( Action “Landfraf”); RG 165/179/649, CSDIC UK, G.R.G.G. 326 (0), op. cit; RG 165/179/663, CSDIC ( UK), S.I.R. 1466, “German Deception Measures”.

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likely, German efforts at disinformation, tempered by Japanese professionalism in

observation and assessment. Oshima and Kojima tended systematically to overstate

German capabilities in the west. They distorted the power of the Atlantic Wall, while

their account of how the Germans planned to smash an allied attack reflected von

Rundstedt’s disinformation, tempered by accurate information from other sources. The

more they relied on what they were told, as against what they could see, the less

accurate became their comments. In October 1943, Oshima distorted German strength

in three major ways, claiming that it included fifteen “mechanized” divisions, 50% more

than was true, if his terminology meant formations capable of offensive action; with

several more on the way-- including two paratroop divisions from Italy, which never

arrived; while the two thirds of the thirty “coastal” divisions that had just two regiments,

were being “greatly reinforced up to the strength of three regiments”, which did not

happen with half of them, with the rest receiving merely “Ost” troops. In May 1944,

Kojima indicated that the forces in France were “all the pick of the German Army”,

implied that almost all LE divisions had three regiments, and overestimated by 100%

the number of Luftwaffe aircraft able to enter the battle. British intelligence found

treasure in these reports, while throwing out the trash, by comparing them to material

from all other sources, including Ultra, and by recognising that these officers were being

misled. As MI 14 noted,” although German senior officers were clearly out to impress

( Oshima) his report, while exaggerating factual information, is a reasoned and well

considered document”. 70 Inadvertently, however, the Japanese estimate of the high

quality of the German preparations for attacks, and of their response to invasion,

reinforced British preconceptions of these matters, and their worst case assumptions on

these matters.

If von Rundstedt’s claims and this analysis of it are correct, one confronts an

abundance of ironies. A great intelligence source, Magic, exposed the allies to a

deception campaign that could have reached them through no other means, but which

did so in a way uncontrolled by its masters. This deception was undone by the

professionalism of officers intended to receive it, and those who did so only through

intelligence, Japanese and British who, penetrating the bodyguard of lies in different

ways, gave truths to Tokyo, and even more to London. German deception failed

70 British Intelligence III/2, pp. 771-75, 787-92.


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because it was countered through excellent intelligence by its allies and enemies, though

even had the effort succeeded in technical terms, probably little would have changed:

defenders never gain easily from deception, especially on so small a scale as this. The

greatest effect of these reports was counter-productive: to reinforce public statements by

German authorities about the power of their defences, and private allied expectations on

the matter, so driving the demand for effective counter measures, including

FORTITUDE.

Equally, British intelligence was essential to the success of FORTITUDE. That

success commonly is overstated, focusing on the eccentricities of intelligence officers and

agents, and also controversial, for general and particular reasons. Deception reinforces

preconceptions, which complicates judgment of its significance, compared to other

elements of its victim’s process of decision making. The influence of FORTITUDE on

OVERLORD also overlaps with that of Special Forces, airpower, and all factors which

limited the redeployment of enemy forces, kinetic or perceptual, internal or external to

German minds. All considered, however, FORTITUDE was essential to victory in

OVERLORD. 71

Preconception drove German assessment, aided by two engines. First, the

Germans failed in the collection of intelligence, the best means to avoid error,

uncertainty and the division of force; even worse, much, perhaps most, of their evidence

was shaped by the enemy. After the war, some staff officers also claimed to have

politicized assessment, by overstating all indicators of allied strength, so to drag

reinforcements to France. If so, inadvertently, these officers served as a document

delivery service for deception. They amplified the effect of the false order of battle

peddled by the deceivers, which led Germans to overrate allied strength in divisions by

almost 50%. Otherwise, the Germans never could have believed that the invasion of

71 Michael Howard, Strategic Deception, British Intelligence in the Second World War, Its

Influence on Strategy and Operations ( Cambridge, 1991), is essential, but must be supplemented by several essays in Michael Handel (ed) Strategic and Operational Deception in The Second World War, ( London, 1989). Other valuable accounts include Katherine Barbier, D-Day Deception: Operation Fortitude and the Normandy Invasion, ( Stackpole, Westport, CT, 2007) , John Ferris, “The Roots of Fortitude: The Evolution of British Deception in The Second World War”, in Thomas Mahnken (ed), The Paradox of Intelligence: Essays in Memory of Michael Handel ( London, 2003), Thaddeus Holt, The Deceivers: Allied Military Deception in The Second World War, ( Scribners, New York, 2004) and Nicholas Rankin, A Genius for Deception, How Cunning Helped the British Win Two World Wars, ( Oxford University Press, New York, 2008) .

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Normandy was a feint, with another army poised to strike the true target, the Pas de

Calais. Second, the allies understood enemy expectations, and exploited them by

evading German strength, striking its weaknesses, dividing its forces and degrading

their deployment, by many means. Among them, security and deception had unique

power, tools to manipulate the assessments which caused actions, rather than stalling

movements as they were made. Germans commonly saw Normandy as an obvious sector

for attack, especially the ports which bracketed it, Cherbourg on the Cotentin peninsula

and Le Havre north of the Seine River. Before the attack, few things prevented

Germany from sending the three to five more divisions to Normandy which would have

cancelled or contained the invasion. On 6 June, even just another good infantry division

at Normandy might have crippled the allies at two places, instead simply of Omaha

Beach. Once the Germans insured the Pas de Calais heavily against risk, Normandy

reached the top of priorities for resources. In the week before D Day, the enemy almost

doubled the capability of that garrison, increasing its German infantry battalions by

over 50% and adding an armoured division; but still it stood below the average force to

space ratio on the Pas de Calais. British deception and security rank high among the

things which blocked that development: they were perhaps the only thing left. That the

Germans came so close to seeing the real danger and to blocking it, proves not the

failure of FORTITUDE, but its success. Almost half of the German forces in the west,

good and mediocre, were badly placed for the attack on Normandy, while the formations

there were just too weak to crush or contain the invasion. All that Germany needed to

defeat an allied attack on Normandy was superiority in intelligence. They were inferior.

FORTITUDE was one of several factors which were essential for the allies to

establish a viable beachhead by D + 2. It was less important after the invasion, but still

notable, on the border between necessary and secondary causes, by short circuiting

German defences. FORTITUDE added little to the collapse in German command above

the divisional level which bought almost 24 precious hours on 6 June. The delay in

decisions enabled the allies to penetrate the beach defences and shatter their defenders,

before the immediate reserve entered the fray, to slow the deployment of the first wave

of reinforcements to the theatre, and to crush counterattacks on 6 and 7 June. These

successes stemmed from the convoluted and fragile German command system in the

west, fuelled by the politics of commanders facing uncertainty and ignorance about

allied capabilities and intentions, which were shaped by deception and security; but also


155

because a false sense that no attack was imminent, stemming from incompetence in

their intelligence, and Eisenhower’s willingness to attack in poor weather, disrupted

decision making, as Rommel flew home for his wife’s birthday, for example. In an alloy

with German preconceptions, however, FORTITUDE slowed the decisions to deploy the

second wave of reinforcements ( including two of the seven Panzer divisions in France)

by two weeks, and of a third wave, of a dozen LE divisions, for almost two months, until

just before the foe collapsed. It also helped to keep six weak divisions ever from entering

the battle. Special Forces and airpower slowed these actions once they occurred, and

others. Without FORTITUDE, none of these achievements are likely to have happened,

let alone all of them, nor to the same degree. Without them, OVERLORD would have

been much less successful, though probably after D + 2, with the establishment of a long

and deep bridgehead, and certainly by D +10, when the allies seized the Cotentin

peninsula and surged on Cherbourg, ensuring control of a major port, Germany could

have contained the allies only had every division in the west immediately moved to

Normandy. Even then, allied victory perhaps was inevitable.

On the Day.

In OVERLORD, intelligence was excellent, and influential. This case shows the

best that can be expected from intelligence, and its limits, and the degree to which

decision makers always must be able to act in the face of uncertainty, error and

ignorance. The conventional assumption is that intelligence for OVERLORD was precise

and powerful, and almost everything right and certain, with some errors. In fact, much

was erroneous or uncertain, but most key things were correct and trusted by the right

people, who were excellent consumers. Montgomery had a weird ability to read an

enemy, and a battle, before the fact; Williams was an analyst of acumen: together, they

were a great intelligence team. Without them, planning for OVERLORD might have

failed. Again, allied intelligence was filled with errors, but since they were not

systematic, many of them cancelled each other out. Others shaped matters which did

not matter —so too often the successes, including the most famous or technically

complex of them. Success was most pronounced at the strategic level, where intelligence

bracketed the truth closely enough to show where it was, or was not. Since planners

and commanders cared about gaps in their information, intelligence was fundamental as

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a source of knowledge, and psychological certainty. Even at this level key issues were

uncertain, like enemy armoured strength, and the speed and scale with which it could

reinforce Normandy. Allied assessments overstated the efficiency of German divisions in

France, and also of their command system, though none could safely have predicted that

the latter would perform so poorly at Normandy as it did. In this instance, worst case

logic spurred effective action. It led SHAEF and 21 Army Group to focus on jamming the

German machine through every means possible, including airstrikes, Special Forces,

mobilization of the French resistance, and deception, in particular, the demand that

FORTITUDE shape German actions long after OVERLORD opened. These means

achieved their end; they might have worked less well had they not been driven by such

fear and uncertainty. Ultimately, these errors had little cost, because they spurred

effective counteraction, their significance was small, and 21 Army Group made the

fewest mistakes and acted on its own views. The greatest area of failure lay at the

operational level; indeed, as on 6 June 1944 tactical and operational problems flowed

together, errors in minor forms of intelligence had major consequences. However, one

may doubt that these failures mattered much, or that successes with them would have

done so either. On 6 June 1944, the problem was the enemy, not intelligence about it.

Intelligence had done well enough, as much as could be expected. The rest was up to the

men.

（カナダ・カルガリー大学歴史学部教授）

Ferris Intelligence Before Overlord - MOD Intelligence Before Overlord 121 Expeditionary Force (...

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