Deception operations were widely used by the Allies throughout the war. They were carried out by secret units in both the U.S. Army and the Navy, as well as by the British, and created complex diversions to keep the Axis powers guessing about the Allies’ true operational intentions. The Americans chosen to be part of these special units were not career military men; they were artists, actors, sound technicians, makeup artists and successful public relations specialists. Many of their efforts remained classified until 1996.
Fortitude-South, as the Pas de Calais feint was called, was critical to the success of the Normandy invasion. Hitler was convinced that the Allies would start their advance on “Fortress Europe” at Calais, France from Dover, England. Called the Strait of Dover, it is the narrowest part of the English Channel. It made tactical sense for the Allies to cross the channel in this area. So, in order to validate this German belief, the Allies built a fictional army in Dover to convince Hitler and his staff.
The Allies built an elaborate physical and communication deception around this fictional army, called the First United States Army Group (FUSAG). Major General George S. Patton was selected to be the commander of this group, and he was photographed often in and around Dover as part of the deception. The Germans knew that an operation such as an invasion of the European mainland would need to be led by a well-known and respected officer. The German military staff had biographies of every major military officer in the Allied military, so if a new face had entered the scene in charge of this Army for such a major invasion, it would have aroused German suspicion.
General Patton and the FUSAG had to, with minimal manning, create the illusion that there was a large troop concentration in Dover training and preparing for the invasion. Tent cities were erected, and kitchen tents kept fires burning, in order to appear functional. Fake aircraft were constructed from pipe and canvas, and set along runways.
Inflatable tanks, jeeps, and other vehicles were constructed. All of these efforts were designed to create an illusion for German reconnaissance planes. At night, men ran carts with lights across the runway, and sound technicians ran tracks of airplanes taking off and landing, in an effort to make the runway appear operational from afar.
But this was only the tip of the Operation Fortitude iceberg. The signals corps transmitted bogus messages. A large volume of scripted radio transmissions were sent on channels known to be exploited by the Germans. Readiness reports, troop movements, supply problems, even benign issues such as emergency leave and pay problems for individual soldiers, were scripted and encrypted in a code known to be broken by the Germans, and transmitted.
In human intelligence and diplomatic channels, similar scripted messages were transmitted. Secret and double agents not just in Europe, but around the globe, were fed scripted information to feed back to their German controllers. Diplomats leaked scripted fake, allied intentions at cocktail parties, and these were overheard and transmitted back to Germany. The scripting was so complex that the Allies would make sure that stories were corroborated from different sources, adding to the overall validity that Pas de Calais would be the Allies foray into France, and it would occur in the middle of July.
When the Allies eventually landed in Normandy on June 6, 1944, the Germans were still bracing for the main attack at Calais. Hitler believed the force landing in Normandy was the deception force, so he did not divert troops or assets from Calais to assist forces on the Cotentin Peninsula. Six days after the invasion at Normandy, Hitler still did not believe that it was the main Allied invasion. Because the invasion at Pas de Calais was supposed to take place at D-day + 45, in the middle of July, the Germans refused to move forces in place in Calais, as they waited for the “main assault” well into the Allied advance.
Operation Fortitude was a huge success, and achieved its objective by allowing Allied forces to successfully establish a beach head in Normandy, and then break out and move across Western Europe. General Patton arrived in France in July 1944, and led the Third Army through the Normandy breakout offensive and across Europe to the Battle of the Bulge and into Germany.
Operation Fortitude was only the beginning of U.S. deception operations in WW II. Troops from the U.S. Army 23rd Headquarters of Special Troops landed in Normandy soon after the main assault, and continued deception operations throughout Europe. The unit’s existence was a well-guarded secret, even kept from U.S. troops. The unit was instrumental in keeping the German Army uncertain about Allied intentions and operations throughout the campaign.
