Most British and Americans have some understanding of D-day, even if the extent of their knowledge is that the Allied invasion was a success. While history makes the Allied victory at Normandy seem like a foregone conclusion, Allied planners never enjoyed such confidence. In 1943 when Allied leadership began making their initial plans for the invasion, most felt it had little chance of success. Even as June 6, 1944 approached, planners still harbored grave concerns about the fate of the upcoming invasion. After months of planning, amassing men and materiel, training and rehearsing, there was nothing left to do but send the men forward and hope the Germans were caught by surprise. The Germans did put up resistance, but the resistance on D-day was significantly less than what it could have been. The Germans were not excepting the invasion of France on June 6, nor were they expecting it at Normandy.

Behind the traditional planning for D-day, there was a massive deception operation underway. Plan Bodyguard sought to deceive the Germans about the exact time and location of the attack. Fortitude South, the effort to convince the Germans that the Allies intended to invade France north of Normandy at the Pas-de-Calais, was the most well-known of the Bodyguard plans, but Plan Zeppelin was the largest and by far the most exhaustive of the deceptions. 

Plan Zeppelin was a deception operation carried out by “A” Force, Britain’s only military deception organization tasked with executing both strategic and tactical deception. It was headed by an unassuming and unconventional British officer, Dudley Clarke. The primary focus of Zeppelin was to pose a threat to the Balkans, a region Adolf Hitler considered an Achilles Heel of sorts – one that was vulnerable to Allied attack. Zeppelin also contained two major subsidiary plans, Turpitude and Vendetta. Plan Turpitude threatened an Allied attack into the Balkans by way of neutral Turkey. Plan Vendetta posed a threat to southern France and was timed to keep Germany’s divisions tied down in the south after D-day commenced in anticipation of an immediate follow-on attack. 

Zeppelin was part of a larger strategy – the Mediterranean Strategy. The Mediterranean Strategy was, at its core, a diversion. By posing threats along the Mediterranean from southern France to the Balkans, to include genuine operations in Italy, the strategy intended to draw German forces south to protect the southern perimeter of Germany’s “Fortress Europe.” Under Clarke’s capable leadership, “A” Force coordinated elaborate strategic deception campaigns designed to manufacture threats across the Mediterranean in an effort to pin down German forces as far away from Normandy as possible – and in some cases in areas the Allies never had any intention of invading. “A” Force also employed deception to aid the British and American armies fighting in Italy. By using diversion and deception, the Allies forced the Germans to spread themselves thin and weaken their forces in France. At the time of D-day, the Germans had 60 divisions spread across the Mediterranean: 25 in the Balkans, 25 in Italy, and 10 in southern France. Not only were those forces not in Normandy, but neither were they close enough to assist the Germans on the western front once the invasion commenced. The result was a resounding success for deception, and ultimately a successful D-day invasion.

Diversion and Deception: Dudley Clarke’s “A” Force and Allied Operations in World War II tells the story of “A” Force and its monumental effort to mislead the Germans prior to D-day – an often overlooked aspect of World War II, and even an overlooked aspect of World War II deception history. This work also demonstrates that the Mediterranean Strategy was not a useless side-show in the Allied war effort, but a crucial component of Allied grand strategy that proved its worth on D-day. Finally, this work combines traditional military history with deception history to create a more holistic understanding of the Allied war effort, specifically in the operational planning stage. Diversion and Deception picks up in 1943 at the end of the North African campaign where my first work concluded. “A” Force: The Origins of British Deception during the Second World War delved into the formation of “A” Force and followed it through its early years, where it had to learn how to deceive through trial and error. By the Second Battle of El Alamein, “A” Force had largely perfected the art of deception and created the deception blueprint that the Allies put to such successful use in preparation for D-day.  

Lastly, it should be noted that this work demonstrates the value of deception as a weapon of war, but importantly, a weapon that can save lives. When deceptions succeeded, battles were shortened, and that meant fewer lives lost on both sides of the fight. It is impossible to know how many lives were saved or to what extent deception contributed to a speedier end to World War II, but it is clear that deception played a vital role in Allied victory. Acknowledging “A” Force’s contribution to the war effort, British Field-Marshal Harold Alexander simply stated: “we would not have won our battles without it.” 

The feature image is from Pexels.