Operation_Fortitude

Operation Fortitude

Operation Fortitude was the codename for the deception operations used by the Allied forces during World War II in connection with the Normandy landings (Operation Overlord). It was divided into Fortitude North, a threat to invade Norway, and Fortitude South, designed to induce the Germans to believe that the main invasion of France would occur in the Pas de Calais rather than Normandy. Fortitude was one of the most successful deception operations of the war and arguably the most important. Both Fortitude North and Fortitude South were related to a wider deception plan called Operation Bodyguard.

Objectives

The principal objective of Fortitude was to ensure that the Germans would not increase their troop presence in Normandy because of the appearance of attacks against German positions elsewhere. Equally important was to delay the movement of German reserves to the Normandy beachhead and prevent a potentially disastrous counterattack. The plan therefore aimed to convince the Germans that additional assaults were planned—specifically in Scandinavia and in the Pas de Calais.

Organization

The overall strategic plan for deception by the Allies in 1944 was planned by London Controlling Section and laid out in Operation Bodyguard. However the actual conduct of such deceptions was the task of the commanders in the theatres in which the deception was to occur. The execution of the deception "cover plan" for Overlord was therefore the responsibility of SHAEF under General. Dwight D. Eisenhower. A special section called "Ops (B)" was established at SHAEF to handle deception.

Means

It was initially envisioned that deception would occur through five main channels:

Physical deception: to mislead the enemy with non-existent units through fake infrastructure and equipment, such as inflatable rubber tanks and plywood artillery. See
Controlled leaks of information through diplomatic channels, which might be passed on via neutral countries to the Germans.
Wireless traffic: the creation of non-existent units through simulation of the wireless traffic that such units would generate, which would be detected by the enemy
Use of German agents controlled by the Allies through the Double Cross System to send false information to the German intelligence services
Public presence of notable staff associated with phantom groups, such as FUSAG (First U.S. Army Group), most notably George S. Patton, the best known senior Allied combat commander.

During the course of Fortitude the almost complete lack of German aerial reconnaissance, together with the absence of uncontrolled German agents in Britain, came to make physical deception almost irrelevant. The unreliability of the "diplomatic leaks" resulted in their discontinuance. The majority of deception was carried out by means of false wireless traffic and through German double agents. The latter proved to be by far the most significant.

In fact, Fortitude was so successful that Hitler regarded the Normandy invasion as a feint: he kept his Panzer units where he expected an attack and away from Normandy, until the battle was decided—in Normandy. Although Fortitude was controlled from SHAEF, London Controlling Section retained responsibility for what was called "Special Means": the use of diplomatic channels and double-agents.

Double agents

The Germans had about 50 agents in England at the time, but B1A (the Counter-Intelligence Division of MI5) had caught all but one of them (he died in unclear circumstances). Many were recruited as double agents. They were used throughout the war to feed German Intelligence a misleading picture, and particularly in the pre-invasion period misleading or imaginary information about invasion preparations. Reports sent by these agents were carefully composed and coordinated to support the view of forces in the UK the Allied deception planners wished to present.

The three most important double agents during the Fortitude operation were:

GARBO: Juan Pujol was a Spaniard who had been recruited to German intelligence and then offered to work for the British. He created a huge network of false sub-agents by the time of Fortitude. He was awarded the Iron Cross after D-Day.
BRUTUS: Roman Garby-Czerniawski was a Polish officer; captured by the Germans, he was offered a chance to work for them as a spy. On his arrival in Britain he immediately turned himself in to British intelligence.
TRICYCLE: Duško Popov, a Yugoslav lawyer.

Fortitude North

Fortitude North was the fictitious assault on Scandinavia. It consisted of two parts: first a plan to re-occupy any parts of occupied Scandinavia that might be weakened by withdrawal of German troops; second an assault on Norway.

The (fictional) unit assigned to this operation was the British Fourth Army, which was located in Scotland. Since it was highly unlikely that a German reconnaissance plane could make it to Scotland and back to German-controlled territory without being shot down, the primary means of deception was the use of double agents. In addition, the radio traffic of the imaginary units assigned to the Fourth Army was simulated by radio operators.

British diplomats also began negotiations with neutral Sweden in order to obtain concessions that would be useful in the event of an invasion of Norway, such as the right to fly reconnaissance missions over Sweden and the right to refuel planes that made emergency landings. These negotiations were made not in the hope of obtaining the concessions but with the intention that news of the negotiations would reach the ears of the Germans.

The units making up Fourth Army varied throughout 1944. Some were real units whose actual role and organization was disguised by agent reports; some were entirely fictitious. The order of battle at the peak of the operation was as follows:

British Fourth Army fictional - HQ Edinburgh

British II Corps (fictional - HQ Stirling)

55th British Division (Northern Ireland)
58th Division (fictional, Aberlour)
British 113th Independent Infantry Brigade (garrison for Orkney and Shetland Islands)

British VII Corps (fictional - HQ Dundee)

British 52nd (Lowland) Infantry Division (Dundee)
U.S. 55th Infantry Division (fictional, Iceland)
Three U.S. Ranger battalions (fictional, Iceland)

United States XV Corps (Northern Ireland)

Fortitude South

Fortitude South was conducted with the intention of convincing the Germans that an invasion would come to the Pas de Calais—a logical strategic choice for an invasion since it was the closest part of France to England and its beaches were not easily defended. While it was hoped that this would reduce the number of troops in the Normandy area at the time of the invasion, even more important was to dissuade the Germans from reinforcing the Normandy battleground in the days immediately after the invasion. To this end the Allies hoped to convince the Germans that the Normandy invasion, when it occurred, was a diversion, and that the main invasion was still to come near Calais.

Operation Quicksilver

The key element of Fortitude South was Operation Quicksilver. It entailed the creation of the belief in German minds that the Allied force consisted of two army groups, 21st Army Group under Montgomery (the genuine Normandy invasion force), and 1st U.S. Army Group (FUSAG) (a fictitious force under General George Patton), positioned in southeastern England for a crossing at the Pas de Calais.

At no point were the Germans fed false documents describing the invasion plans. Instead they were allowed to construct a misleading order of battle for the Allied forces. To mount a massive invasion of Europe from England, military planners had little choice but to stage units around the country with those that would land first nearest to the embarkation point. By placing FUSAG in the south-east, German intelligence would (and did) deduce that the center of the invasion force was opposite Calais, the point on the French coast closest to England and therefore a likely landing point.

In order to facilitate this deception additional buildings were constructed; dummy vehicles and landing craft were placed around possible embarkation points. It was originally intended to make many such fakes, but the extremely low level of German aerial reconnaissence and the belief that most German spies were under British control meant that such effort were reduced to a minimum. A huge amount of false radio traffic was transmitted, commensurate with a force of that size.

A deception of such a size required input from many organisations, including MI5, MI6, SHAEF via Ops B, and the armed services. Information from the various deception agencies was organized by and channeled through the London Controlling Section under the direction of Lieutenant-Colonel John Bevan.

Results

The Allies were able to judge the effectiveness of these strategies. ULTRA intelligence — that gained from the breaking of German codes and ciphers, such as the Enigma machine — was able to provide an indication of the German high command's responses to their actions. They maintained the pretence of FUSAG and other forces threatening Pas de Calais for some considerable time after D-Day, possibly even as late as September 1944. This was vital to the success of the Allied plan since it forced the Germans to keep most of their reserves bottled up waiting for an attack on Calais which never came, thereby allowing the Allies to maintain and build upon their marginal foothold in Normandy.

Reasons for success

Some of the key reasons why this operation was so successful:

The long term view taken by British Intelligence to cultivate these agents as channels of disinformation to the enemy.
The use of Ultra decrypts to read Enigma-coded messages between Abwehr and the German High Command, which quickly told them the effectiveness of the deception tactics. This is one of the early uses of a closed-loop deception system.
R V Jones, the Assistant Director Intelligence (Science) at the British Air Ministry insisted for reasons of tactical deception that for every radar station attacked within the real invasion area, two were to be attacked outside it.
The extensive nature of the German Intelligence machinery, and the rivalry amongst the various elements.
The respect held by the Germans for General Patton; part of deception was already accomplished because they always believed he would be the Allies' choice to lead the invasion.

In fiction

Eye of the Needle, is a novel (and subsequent movie) about a Nazi spy figuring out the Allied deception and racing to let the German leadership know. Another book, The Unlikely Spy is a novel that focuses on both Allied attempts to carry out Fortitude, as well as a German agent's race to discover the true plans.

References

Howard, Sir Michael, Strategic Deception (British Intelligence in the Second World War, Volume 5) (Cambridge University Press, New York, 1990)
Holt, Thaddeus, The Deceivers: Allied Military Deception in the Second World War (Scribner, New York, 2004)
Harris, Tomas, "GARBO, The Spy Who Saved D-Day", Richmond, Surrey, England: Public Record Office, 2000, ISBN 1-873162-81-2
Hesketh, Roger, "Fortitude", Overlook Press, New York, 2000, ISBN 1-58567-075-8
Latimer, Jon, "Deception in War", Overlook Press, New York, 2001 ISBN 978-1585673810