Just after midnight on 6 June 1944, Germany’s top spy in Britain – codename: Arabel – began transmitting from the bedroom of a quiet semi-detached house in the suburbs of London. In the course of the next hour the agent disclosed to his handlers in Berlin the complete battle order of the allied invasion forces that were already on their way to the Normandy coast. Over the next few hours, Arabel’s warnings were confirmed by reports of parachutists landing on the Cotentin Peninsula and in the area to the south of Caen. Hydrophone operators based in Cherbourg reported being almost deafened by the sound of thousands of ship propellers drawing closer across the English Channel.
In the following days, Arabel’s information was to prove to be so accurate that the Germans were to consider this agent’s information reliable for the remainder of the war. But Arabel – known to the British as Agent Garbo – had included one entirely fictional detail in the information he transmitted to Berlin; that the assault on Normandy was not the planned invasion of North Western Europe, but a feint designed to lure forces of the Fifteenth Army away from the Pas de Calais where Patton’s First American Army Group would spearhead the real invasion in the coming days.
There was no First American Army Group. Patton – who the Germans correctly believed to be the western allies’ most competent general – had been put in charge of a dummy army equipped with inflatable rubber tanks and trucks; which the RAF had allowed German reconnaissance flights to observe. To add to the deception, real British, Canadian and US radio transmissions were routed via landlines to transmitters in Kent where the mythical US army group was supposedly based. Additionally, British and American bombing missions in the weeks leading up to the invasion dropped five bombs behind the Calais coast for every three dropped in Normandy; again, confirming the German assessment that the invasion would come across the narrowest part of the English Channel.
For more than a year, the British had maintained two deception plans – codenamed Fortitude North (the invasion of Norway) and Fortitude South (the invasion of the Pas de Calais). When, in May 1944 they halted Fortitude North, the Germans – discounting the possibility that the British could run two deception plans – bought into the Fortitude South deception. Any piece of information they received thereafter that suggested an alternative was discounted.
The big success in the intelligence war had come years earlier, when Britain’s security services rounded up all – not, some or most, but every single one – of Germany’s spies in the UK. Some were shot; others imprisoned. But a few were turned and became XX (double cross) spies feeding deceptive information back to their handlers. If Germany had had any genuine spies left in Britain, the Arabel deception might well have been exposed; alerting the Germans to the full scale of the Normandy landings. As it was, the Arabel deception was swallowed hook, line and sinker.
The intelligence war was but one strand of the complexity behind the D-Day landings; all of which had to come together to allow the successful invasion of the continent. The clearing of the Mediterranean in 1943 had been essential to freeing up shipping (routing around Cape Hope required three ships for every one required for the Suez Canal route) needed for the invasion. The defeat of the U-boats in the second half of 1943 had allowed the men and equipment required for the invasion to be safely transported across the Atlantic. The arrival of the P51 Mustang long-range fighter in Europe early in 1944 finally defeated the Luftwaffe; providing the Allies with air supremacy over North West Europe. Meanwhile, the success of the Royal Air Force in preventing German surveillance of the British mainland allowed the concentration of the invasion force to go unnoticed.
In the intelligence war, however, we also find the seed of misunderstanding that plagued the Allied planners for the duration of the war. In an informal discussion during the Casablanca Conference in 1943, US Chief of Staff General George Marshall suggested to his British counterpart General Alan Brooke; that the Allies should simply land on the west coast of France, as this would bring the war to an early conclusion. Brooke’s sardonic response was that this would indeed bring the war to an early end “but not in the way we would want.” This discussion epitomises the differences between the two allies; which can be summarised thus: the Americans wanted to invade Europe in order to defeat Germany whereas the British wanted to defeat Germany in order to invade Europe. And since, prior to September 1944, the British Empire would provide the majority of the troops; the Americans were obliged to give ground.
Japanese Admiral Isoroku Yamamoto – architect of the carrier attack on Pearl Harbour – is reputed to have lamented afterward that:
“I fear all we have done is awaken a sleeping giant and fill him with terrible resolve.”
The quote – which appears in the 1970 film Tora, Tora, Tora! – is probably false. Nevertheless, the USA that was drawn into war in December 1941 was, indeed, sleeping. Even at the time of the famous carrier battle around Midway Island in May-June 1942, American leaders feared that a Japanese invasion of the USA could not be prevented and that in the worst case, ill-equipped and outnumbered US troops would have to retreat to the Rocky Mountains and behind the Arizona Desert to secure a stable defence line.
Worse still, on 8 December 1941, America’s leaders found themselves at war with the wrong Axis partner. Militarily and politically, Germany was the far greater foe because a German victory over the Soviet Union – the outskirts of whose capital city was the scene of bitter fighting at the time of Pearl Harbour – would make it impossible for the USA – still less the British Empire – to win a European war. On 10 December, Hitler – in one of his most irrational decisions of the war – resolved this problem for the Americans by declaring war on them. This gave the American leaders the war they wanted. What they lacked in December 1941 was the means to fight it.
Attempts to goad the British into anything more than a raid on the coast of Europe failed simply because the American planners could not provide the shipping and equipment required to succeed. In some quarters – most notably the Anglophobic head of the US Navy, Admiral King – there was a desire to ignore Germany and focus on defeating Japan. Roosevelt was, however, quite clear and quite correct in assessing that any number of Japanese successes in the Pacific could eventually be reversed whereas a German victory in Europe would be permanent.
The problem in 1942 – in the months before America’s vast mineral reserves and massive civilian productive capacity could be turned to military purposes – was how to take the war to Germany. A direct invasion of Europe was out of the question. But with mid-term elections looming, the Roosevelt administration had to be seen to be doing something. As a result, and almost by accident, the Americans got drawn into North Africa for much the same reason as the British had. In Britain’s case in 1940, North Africa was the one place where British and Axis (Italian) forces faced each other. In America’s case, the German defeat of the British at Tobruk in June 1942 obliged them to go to North Africa as the only place on the planet where American troops could fight against Germans.
Clearing the Mediterranean shipping routes required the clearing of North Africa (which also dictated an American-led assault on French North Africa). The inherent danger, however, was that the North African campaign would drag on into 1943 (the capture of Tunis eventually took until May 1943); effectively ruling out an invasion of North West Europe in that year. This raised the question – which exercised Marshall and Brooke – of what to do next. It was inconceivable that the allied armies that had cleared North Africa could simply go on holiday for a year while the men and material required for the cross-channel invasion were built up. This, much to the annoyance of the American planners, made Sicily the obvious target; and if the allies were going to Sicily, the Italian mainland was the inevitable next step.
Popular history has tended to portray the arguments around the Italian campaign as centring on Churchill’s political desire to find a route into Central Europe ahead of the Red Army and a US military staff concerned solely with ending the war as quickly and economically as possible. In fact, Churchill’s wilful stupidity only became an issue in 1944; largely in response to Britain’s fading political influence with both the USA and the USSR. In 1943, British planners sought an invasion of Italy for sound military reasons.
Brooke – a First World War artillery officer who had commanded a Corp of the British Expeditionary Force during the retreat to Dunkirk in May-June 1940 – was painfully aware of the threat from the efficient East-West transport links (autobahns and railways) that the Germans had built in the years before the war. In early 1943 – prior to the historic defeat of the German panzer armies around Kursk in July – Brooke’s fear was that the Germans would be able to reinforce their armies in Northern France by land far more rapidly than the invading Allies could reinforce theirs by sea. German north-south communications were another matter. Brooke reasoned that an invasion of mainland Italy would oblige the Germans to move forces south of the Alps, from where they could not interfere with a cross-channel landing. Furthermore, the presence in Italy of Allied forces opened the threat of further invasions into the Balkans (where the Germans were already struggling to suppress Yugoslavian and Greek partisans) or into Southern France (where the Americans eventually landed in August 1944). Nor could the Germans afford to discount the possibility that, left undefended, Italy might provide the Allies with a route into Austria and Southern Germany. And so an Allied force in Italy could tie down a much larger German force in Southern Europe from where they could not be recalled to Northern France in time to make a difference.
Although the American planners feared that their British counterparts were seeking to avoid a commitment to a cross-channel invasion, they were also forced to accept the logic of the British argument. In early 1943, the U-boats came close to defeating the Allies’ Atlantic convoy system; the Luftwaffe still enjoyed air superiority over the invasion area; and despite the defeat unfolding in Southern Russia, the German armies were superior to any Anglo-American force that could be thrown against them. Only when these threats had been neutralised could the Allies be confident that an invading force would not be pushed back into the sea. And so Allied planners were given an extra year to plan for the invasion, while Allied forces fought the Germans where they could rather than where they might ideally have chosen.
The additional planning – overseen by Eisenhower as supreme commander and Montgomery as ground forces commander – saved the Allies from disaster. The original invasion plan involved far too small an invasion force; landing just three seaborne divisions in a much smaller beachhead. Under Eisenhower and Montgomery this was broadened to a seaborne landing of five divisions, together with landings of one British and two American airborne divisions on either flank of the invasion area. The logistics chain required to support the invasion was mind-boggling. A fleet of 713 warships was deployed to protect the cross-channel convoys and to act as artillery for the invading armies. These efforts were complemented by some 11,500 aircraft as protection against German surface units and what remained of the Luftwaffe in the invasion area; as additional bombardment of targets in the invasion area; and to interdict German communications to prevent or slow the movement of German forces toward the beachhead.
Some 157,000 men in eight divisions were to be landed in Normandy on D-Day; a further five divisions were to go ashore on the following day, with another four landing in the next two days. To ensure that these troops were properly supplied required an armada of more than 4,500 supply ships ferrying arms and equipment across the channel.
The allied intention was to capture the port of Cherbourg in the first three weeks after the invasion. However, the Germans were expected to destroy the port facilities, leaving the Allies without an operational port for weeks after its capture. To overcome this problem, the Allies brought two artificial ports – codenamed Mulberry – with them. Nevertheless, the need to supply forces across open beaches – a problem that was exacerbated when one of the Mulberries was destroyed by a storm on 19 June – was to help dash Allied hopes of bring the war to an end in 1944.
The planning and logistics for the invasion were so complex that they created perhaps the biggest flaw in Allied planning. As historian H.P. Willmott has argued, in 1944 the Allies had a plan to invade Northwest Europe but they lacked a plan to win the war. This has been obscured to a great extent by Montgomery’s nasty habit of rewriting the history of all of his battles so that they appear to have turned out exactly as planned. Montgomery was to claim that the Normandy plan had envisaged the British and Canadians holding the Germans around Caen in order for the Americans to break out in the west. The distribution of armoured forces says otherwise. Two thirds of the armour was landed in the British sector where the plan had optimistically envisioned the capture of Caen on D-Day itself, followed by an armoured breakout onto the plains to the south. The Americans, in contrast, had left most of their armour in reserve because their role called for merely holding the base of the Cotentin Peninsula while the bulk of their forces assaulted Cherbourg across bocage country unsuitable for armoured operations.
This element of the plan owes itself to a two accidents of geography. First, the location of British ports large enough to embark an invasion force effectively ruled out an invasion of the Pas de Calais area – there was simply too much risk in moving the American forces through the Strait of Dover. Moreover, the narrow eastern end of the Channel lacked the space required by an armada of more than 5,000 ships; each traveling different distances at varying speeds, but all of which had to arrive off the coast at the same time and in the correct order.
Second, it made no sense to transport the American forces from the western ports where they arrived across southern England to ports in the east, while moving British forces in the opposite direction… a recipe for chaos. Divide southern England along a line north of Poole, and the American forces were to the west and the British and Canadians to the east. This deployment was to have major ramifications for the conduct of the war beyond the invasion beaches, and continues to echo in the shape of NATO deployment today.
Although the British Empire provided the majority of the invasion forces on D-Day itself, Britain was reaching its manpower limits. By the autumn of 1944, the British would be forced to demobilise frontline troops in order to provide industrial manpower at home. The Americans, in contrast, were just beginning to deploy their full strength. What this meant was that while the British might have been better placed to assault the primary target of Caen on D-Day itself; it was the Americans who were best equipped to carry the battle beyond the beaches. It is likely that the allies would not have been bogged down in the beachhead for 49 days if the British had been landed in the west and the Americans in the east of the invasion area.
The deployment had political ramifications too. On 13 June 1944, while the allies were still struggling to consolidate their bridgehead, the first German V1 flying bomb was launched against London. This provided the British with an additional incentive – beyond the capture of ports – to drive northeast along the Channel coast in order to capture the launch sites. This, however, left the Americans in a supporting role to the main British line of attack; which was unacceptable to American commanders whose forces were increasingly providing the bulk of the fighting forces.
Roosevelt was up for election in November 1944, and was keen for the American forces to be seen to be carrying the war into Germany itself. However, by deploying the US armies in the west, this was not possible because their line of advance was away from the key Ruhr valley industrial region; Germany’s second city and port of Hamburg; and from Berlin itself. Thus, although Patton’s Third Army was the closest Allied force to Berlin in September 1944, the bulk of allied supplies – still moving across the Normandy beaches – were given to the British.
This gave rise to the so-called “broad front v narrow front” controversy. Montgomery argued that the British be given the bulk of the materiel in order to drive a single spearhead across the Rhine. Supreme Commander Eisenhower, in contrast, opted for a broad drive across the whole front. But the controversy owes more to politics in a US election year than to military considerations. These, in turn, can be traced back to the accident of geography that placed the American forces in southwest England prior to D-Day. Had Montgomery’s Twenty-First Army Group been deployed in the south and Bradley’s Twelfth Army Group been in the north, it is hard to believe that Patton’s spearhead would not have been given the supplies required to cross the Rhine before the Germans had time to regroup and eventually counterattack in December 1944. As it was, Montgomery received the bulk of the equipment and manpower; and squandered it on the ill-fated attempt to cross the Rhine at Arnhem.
Arguably, the unsatisfactory conclusion of the Second World War itself – which saw Eisenhower decline to assault Berlin; and resulted in the US armies driving south toward Austria and a link up with the Armies in northern Italy, while the Canadians liberated Holland and the British drove to Denmark – also flows from the accidental deployment in the build up to D-Day. Given that the Red Army suffered more than a quarter of a million casualties capturing Berlin in 1945, Eisenhower’s decision to give them a free hand was militarily sound even if politically naïve. More important, however is that other than for a brief moment in March 1945 (when the Red Army was already poised for the final assault on the city), after the Americans unexpectedly captured an intact railway bridge across the Rhine at Remagen, the road to Berlin was never open to them. The rapid disintegration of German forces in the west following the crossing of the Rhine could not have been predicted in advance. And in the face of serious opposition, any assault on Berlin would have to be led by the British – an option that was unacceptable to American leaders who were already imposing their hegemony over the nations of Western Europe.
D-Day was the swansong of a British Empire whose existence even then was underwritten by American largesse. Within weeks, the Americans would be deploying more troops and equipment than the British Empire. The accident of geography placed the various allied armies where they ended the war. The irony was that in late summer 1944 the Americans had the manpower, equipment and leadership to drive into Germany but were not in the correct location to do so. And it was no part of Roosevelt’s plan during a presidential campaign to allow a British Empire which many Americans believed to be at least as bad as the Soviet Union, to win the glory of leading the final defeat of Nazi Germany.
As you made it to the end…
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