In their urgent preparations against invasion during the last weeks of May 1940, the British military and civil authorities laboured under a profound delusion. At this time, the Germans had no detailed plans whatsoever to invade England. When the Chiefs of Staff warned on 28 May that ‘an attack is imminent’ they were mistaken. All the energies of the Wehrmacht were concentrated on the defeat of France and the Low Countries. Operations across the Channel by sea or air had never come under serious consideration before the western offensive was launched on 10 May.
The lack of any comprehensive German strategy for invasion reflected Hitler’s own ambivalence towards England, which oscillated between hatred and admiration. On one hand he saw Britain as potentially the biggest obstacle to his dreams of European domination. On the other, he cherished a deep respect for Britain’s achievements, especially in building her empire and defeating her continental enemies, and was inclined to see the British establishment, including the class system, Oxbridge and the elite public schools, as a bulwark against Bolshevism. On one occasion, the German army’s chief of staff General Franz Halder entered the Führer’s office to find him happily leafing through a copy of the Illustrated London News. Hitler looked up from the magazine and said, ‘That we have to make war against such personages, isn’t it a pity?’ Mixed with this high regard for Britain’s record was his belief, so characteristic of his racially fixated ideology, that the Anglo-Saxon people were essentially of the same ethnic stock as the Germans.
Apart from his contradictory attitudes towards British nationhood, there were two more practical factors that had prevented him developing any invasion plan during the first nine months of the war. One was his lack of interest in naval policy. Filled with visions of conquest by land to expand the Lebensraum, or living space, for the German people, he treated the army and the Luftwaffe as far greater military priorities than the Kriegsmarine. On a personal level, Hitler felt little attraction to nautical activities. Forests and mountains were where he liked to relax, not by the sea, which he regarded as alien, even intimidating territory. ‘On land I feel like a lion but at sea I am a coward,’ he once admitted. Just as importantly, he believed that Britain would capitulate if France were defeated. With the Reich all-powerful on the continent, he did not see any reason why the war would continue since Britain’s cause would have become so hopeless. The collapse of France would force the British government to seek terms. Indeed, one of the key goals of the western offensive, he said, was ‘to bring England to its knees’.
According to Hitler, if Britain refused to surrender in the event of France’s collapse, then she could be strangled into submission by cutting off her supplies, making invasion unnecessary. He told a conference of his commanders in May 1939, ‘Britain can be blockaded from western France at close quarters by the Luftwaffe, while the Navy with their submarines can extend the range of the blockade.’
When the commander-in-chief of the Kriegsmarine, Grand Admiral Erich Raeder, met Hitler on 23 September 1939 to discuss naval operations in the West, the Führer again made no reference to any amphibious landings on the English coast, urging instead an aggressive naval blockade if the war continued against France and Britain. ‘The quicker the start and the more brutal, the quicker the effect and the shorter the war,’ he told Raeder. Nevertheless, for all Hitler’s indifference, Raeder recognised that the Reich might well have to mount an invasion.
Ambitious, eccentric and puritanical, the grand admiral was also methodical and well organised. What he feared was a sudden demand from Hitler or the Wehrmacht Chief of Staff for the provision of an invasion fleet, complete with troop transports and convoy protection. Although the possibility of invasion might seem remote, Raeder felt he should be prepared for it, particularly since, throughout the autumn of 1939, Hitler was plotting an assault on France, code-named Case Yellow. As Raeder later wrote of the preliminary analysis by the naval war staff:
It was clear to us that studies should be made in case developments of the war suddenly presented us with a new twist to the English problem … Although the British people had been haunted from the first by the spectre of invasion, there had been not the slightest thought of this on the German side. It was only natural, however, that this problem would one day be given attention by the armed forces command, and I wanted to have some soundly reasoned particulars on hand when that time came, so that the thinking could at least begin on a firm basis. The Navy would be the first of the armed forces to be concerned with an invasion, since it would be a question of overseas transport on a colossal scale.
To carry out this technical study, on 15 November Raeder appointed a small team under Rear Admiral Otto Schniewind. The naval planners went to work with speed rather than enthusiasm. Within a fortnight they had produced the tentative outline of an invasion scheme, code-named Study Red, which envisaged a landing area about 60 miles wide on the southern English coast between Portland in Dorset and Yarmouth. The attacking force, which was to number only 7,500 men carried in about fifteen ships, could theoretically embark from the French Channel ports if they had been seized, but that would leave it highly exposed to enemy fire, as well as depriving it of the element of surprise. Therefore, said the planners, embarkation from Germany would be preferable, despite the longer sea route, although an alternative would be to use Antwerp and Amsterdam.
Study Red was essentially pessimistic, with a strong emphasis on the difficulties that any invading force would encounter, such as the strength of British coastal artillery, the mobility of defensive British troops, the threat from Royal Navy submarines, the large amount of shipping required and, above all, the need to establish air superiority over the RAF. As the naval planners pointed out, the paradox was that if all the conditions were achieved to make an invasion possible, especially the defeat of the RAF and the Royal Navy, then Britain would have already been beaten: ‘thus a landing, followed by occupation, will scarcely be necessary.’
This negativity was important, setting the tone for the naval staff’s attitude towards Operation Sea Lion. Throughout the summer of 1940, Raeder and his senior officers remained highly dubious about the whole enterprise, always pushing for a postponement in the invasion or the use of an alternative strategy to subjugate England. Halder noted in his diary on 30 July 1940 after one unproductive conference, ‘The navy in all probability will not provide us this autumn with the means for a successful invasion.’ However, the army was more bullish, as was shown when Schniewind sent his Study Red to the Oberkommando des Heeres (OKH), the supreme command of the German army under Field Marshal Walther von Brauchitsch.
In late 1939, having received the naval plan, von Brauchitsch ordered a counter-study to be conducted by one of his officers, Helmuth Stieff, who was renowned for his organisational skills, although Hitler disliked him, calling him ‘a poisonous little dwarf’. Adopting a more optimistic, less hesitant approach than the naval staff, Stieff drew up an invasion plan, code-named Study North-West, which proposed a series of landings, not on the southern coast, but on the East Anglian shoreline between the Thames Estuary and the Wash. Speed and surprise were the scheme’s key elements. The proposed initial assault would be made up of three or four infantry divisions, along with the 7th Parachute Division, followed by a second wave of two panzer divisions and one motorised division. There would also be a diversionary attack by two divisions north of the Humber to draw British troops away from Norfolk and Suffolk. As the first two invasion strikes moved inland from the coast, a third wave of troops would be landed in East Anglia to ensure the defeat of the British army and to help cut off London from the rest of the country. In contrast to the small invasion force proposed by the Kriegsmarine, Stieff’s plan involved roughly 100,000 men.
The response to his proposal demonstrated the serious lack of unity within the top echelons of the German military, something that was to hinder the preparations for Sea Lion in the months ahead. Raeder’s staff regarded the OKH scheme as completely unrealistic, both in scale and in geography.
As they explained in their reply of 8 January 1940, they believed that the East Anglian ports of Lowestoft and Great Yarmouth were too small for major unloading operations, as well as being heavily defended by the Royal Navy. Moreover, the idea of a diversionary operation in the north would only further weaken the Kriegsmarine’s already limited resources. Indeed, the fleet stipulated in Stieff’s plan far exceeded German maritime strength. ‘The transport required for the forces specified by the General Staff amounts to 400 medium-sized steamers, with in addition a large collection of auxiliary vessels of the most varied nature, some of which must first be constructed.’ The Kriegsmarine estimated that it would probably take a year for such construction work. What made the OKH plan even less feasible, declared Raeder’s staff, was the power of the Royal Navy. ‘The British Home fleet will always be able to appear in greater strength than our own fleet, if the will is there.’
Just as dismissive of Stieff’s scheme was the Luftwaffe, headed by the gargantuan, egocentric figure of Herman Goering. Even more than the Kriegsmarine, the Luftwaffe was always averse to the concept of invasion, partly because Goering, an ideological believer in the pivotal influence of modern air power, thought that his own force could single-handedly overwhelm Britain. This same attitude prevailed in December 1939, when the Luftwaffe staff responded to Stieff’s scheme: ‘The planned operation can only be considered under conditions of absolute air superiority, and even then only if surprise is ensured.’ In conclusion, the Luftwaffe argued that ‘a combined operation with a landing in England as its object must be rejected. It would only be the last act of a war against England which had already taken a victorious course, as otherwise the conditions required for the success of a combined operation do not exist.’