Raeder's purpose in this case, unlike his energetic promotion of the occupation of Norway (Operation weser), was to forestall any attempt by others to influence Hitler for a rash descent on Britain. The Naval Command still had reservations against an invasion, especially after heavy losses in the Norwegian Campaign, and Raeder continued to argue that the primary focus should remain on the surface, air, and U-boat campaign against Britain's maritime supply lines. Even with Germany's improved geographic position as a consequence of its acquisition of the French Atlantic and Channel ports, available sealift transport and landing craft were both lacking.
With the defeat of France, Hitler still held to his idea that the British would see reason and be forced to the peace table. He also feared that a total defeat of England would benefit the United States and Japan. The failure of London to respond to Hitler's peace feelers, however, led him to issue a directive on 2 July to initiate immediate preparations for an invasion. On 16 July, Hitler issued Directive 16, "On Preparation for a Landing Operation against England," which placed the navy primarily in a transport role. The key precondition for Operation sea lion, as the invasion of Britain was to be known, projected for 15 September 1940, was German air superiority.
The German army's demand for a broad-front landing caused an intense debate with naval leaders, who preferred a narrow-front approach. Both services vigorously sought to persuade Hitler to support their proposal. Initially, the army won support for its plans, but a compromise was eventually reached on 26 August. The army also had no real enthusiasm for an enterprise that, as Raeder lectured them, was not another river crossing. In its planning, the navy estimated that convoying 13 divisions in the initial assault wave against Britain would require 155 transports and more than 3,000 smaller craft: 1,720 barges, 470 tugs, and 1,160 motorboats. Conflicting interests and rivalries prevented any real collaboration among the army, navy, and air force.
The massive preparations undertaken by the navy to assemble the necessary landing craft have been well documented and indicate that the navy did its best to comply with the Führer's decision. However, the debate still lingers as to whether sea lion was simply a propaganda ploy and a diversion for other military operations, especially as Hitler was already contemplating an invasion of the Soviet Union. Certainly, Raeder was sceptical, and he persistently pointed out the impact of the invasion preparations on the navy and maritime transportation, as well as the risks of mounting an operation and supplying an invasion force of at least 40 divisions in waters controlled by the enemy. For Raeder, sea lion remained a last resort, but he loyally continued preparations. Even as he began to sense Hitler's equivocation over sea lion, Raeder spoke positively of the chances for a successful landing.
On 1 August 1940, a Hitler directive ordered the Luftwaffe to switch its preinvasion tactics to a strategic air offensive and to be prepared to switch targets at any time if a new invasion date was set. The failure of the Luftwaffe to control the skies over Britain and the approach of bad weather resulted in the decision to indefinitely postpone the invasion. On 12 October, sea lion was definitively deferred until the spring of 1941. Until 1942, it continued to serve as a deception.
For Hitler, sea lion became a means of psychological warfare. Raeder continued to report on the navy's ongoing planning efforts (e.g., the development of new landing craft), but, as he later reflected, these had been to no effect and had needlessly tied up resources. Yet sea lion had allowed Raeder to keep the navy and its needs in front of the Führer. If the navy's grand building plans in the aftermath of a defeat of the Soviet Union had been successful, no direct attack on Britain would have been necessary.
Keith W. Bird
Ansel, Walter. Hitler Confronts England. Durham, NC: Duke University Press, 1960.; Kiesler, Egbert. Hitler on the Doorstep: Operation "Sea Lion": The German Plan to Invade Britain, 1940. Annapolis, MD: Naval Institute Press, 1997.; Salewski, Michael. Die Deutsche Seekriegsleitung: 1939–1945. Bd. I: 1935–1941. Frankfurt am Main: Bernard and Graefe, 1970.