Operation Overlord
On June 6, 1944, the United States, Britain and Canada launched the largest force of warships in history across the English Channel, escorting the largest concentration of troop transport vessels ever assembled, covered by the largest force of fighter and bomber aircraft ever brought together, preceded by a fleet of air transports that had carried tens of thousands of paratroopers and glider-borne troops to Normandy. Not one German submarine, not one small boat, not one airplane, not one radar set, not one German anywhere detected this movement. As General Walter Warlimont, deputy head of operations of the German Supreme Headquarters, later confessed, on the eve of Overlord the Wehrmacht leaders "had not the slightest idea that the decisive event of the war was upon them."
None of the surprises obtained in World War II was more complex, more difficult, more important or more successful than Overlord. The Allies convinced Hitler and his generals that the battle was coming where it was not, and that the real thing was a feint. They did so by attacking in an unexpected, indeed, illogical place, while pretending their invasion force was much stronger than it actually was.
That there would be landings in France in the late spring of 1944 was universally known. Exactly where and when were the questions. To learn those secrets, the Germans maintained a huge intelligence organization that included spies inside Britain, air reconnaissance, monitoring of the British press and BBC, radio intercept stations, decoding experts, interrogation of Allied airmen shot down in Germany, research on Allied economies and more.
The importance of surprise was obvious. In World War I it was judged that to have any chance at success, the attacking force had to outnumber the defenders by at least three to one. But in Overlord the 175,000-man attacking force would be outnumbered by the Wehrmacht, even at the point of attack, and the overall figures (German troops in Western Europe versus Allied troops in the United Kingdom) showed a two-to-one German advantage. Doctrine in the German army was to meet an attack with an immedi- ate counterattack. In this case, the Germans could move reinforcements to the battle much faster than the Allies because they could bring them in by train, by truck and on foot, while the Allies had to bring them in by ship. The Germans had storage and supply dumps all --No" over France; the Allies had to bring every shell, every bullet, every drop of gasoline, every bandage across the Channel. Allied intelligence worked up precise tables on the Germans' ability to move reinforcements into the battle area. The conclusion was that if the Germans correctly gauged Overlord as the main assault and marched immediately, within a month they could concentrate 31 divisions in the battle area, including nine panzer divisions. The Allies could not match that buildup rate.
None of the surprises obtained in World War II was more complex, more difficult, more important or more successful than Overlord. The Allies convinced Hitler and his generals that the battle was coming where it was not, and that the real thing was a feint. They did so by attacking in an unexpected, indeed, illogical place, while pretending their invasion force was much stronger than it actually was.
That there would be landings in France in the late spring of 1944 was universally known. Exactly where and when were the questions. To learn those secrets, the Germans maintained a huge intelligence organization that included spies inside Britain, air reconnaissance, monitoring of the British press and BBC, radio intercept stations, decoding experts, interrogation of Allied airmen shot down in Germany, research on Allied economies and more.
The importance of surprise was obvious. In World War I it was judged that to have any chance at success, the attacking force had to outnumber the defenders by at least three to one. But in Overlord the 175,000-man attacking force would be outnumbered by the Wehrmacht, even at the point of attack, and the overall figures (German troops in Western Europe versus Allied troops in the United Kingdom) showed a two-to-one German advantage. Doctrine in the German army was to meet an attack with an immedi- ate counterattack. In this case, the Germans could move reinforcements to the battle much faster than the Allies because they could bring them in by train, by truck and on foot, while the Allies had to bring them in by ship. The Germans had storage and supply dumps all --No" over France; the Allies had to bring every shell, every bullet, every drop of gasoline, every bandage across the Channel. Allied intelligence worked up precise tables on the Germans' ability to move reinforcements into the battle area. The conclusion was that if the Germans correctly gauged Overlord as the main assault and marched immediately, within a month they could concentrate 31 divisions in the battle area, including nine panzer divisions. The Allies could not match that buildup rate.