17 September 1940
On 17 September, following the decisive air battle over London and the South of England two days previously, Hitler summoned a meeting with Reichsmarschall Hermann Göring and Field Marshal Gerd von Rundstedt to assess the situation. It had become clear that the Luftwaffe had failed in securing full control of the skies, even through a concentrated five-day attack on London – which by the time had already been extended to nine days.
The destruction of the RAF, set as a precondition for invasion in Führer´s directive No. 17 of 1 August was obviously still not met. Considering the fact that the Luftwaffe had been unsuccesfully trying to achieve its objective for over a month, Hitler concluded that the idea of the invasion was no longer viable.
Even though many historians argue today that Führer’s support for the invasion had been lukewarm from the very beginning, his decision had probably more to do with simple arithmetics than strategic wisdom. Besides all the military matters, the time for Operation Sea Lion was dictated by the tides on the Channel. 17 September marked the last opportunity to give a go-ahead before a period of low waters. The next, and the only opportunity still remaining was on 27 September. After that, the time window before the onset of bad weather would become too short even for the most die-hard advocates of Blitzkrieg.
The status air operation against Britain was clearly unsatisfactory, even though Goering might have once again tried to convince Hitler about another “four or five days of good weather” scheme. On a pervious day, he had been meeting his commanders in France. Witnesses of that meeting later recalled that he had great difficulty in holding his tempers. He admitted that “there were serious lessons to be learned from what happened yesterday” and was convinced that the RAF found new, previously held back reserves. His disillusioned commanders were forcefully persuaded into another change of tactics – even smaller bomber formations, even stronger fighter protection. He openly called for “one more push”, arguing that his Luftwaffe was letting him down.
If the Reichsmarschall indeed relayed his new plan to Hitler, his arguments fell on deaf ears. The German air superiority was most obviously lacking, and the remaining strength of the RAF remained unknown. Coordination among three branches of the armed forces – the Luftwaffe, Heer and Kriegsmarine – during the tremendous undertaking posed by the Channel crossing did not justify such risk.
The Luftwaffe ran out of time.
Hitler’s official decision read:
“Taking account of the meteorological situation as a whole, there are no grounds for expecting a period of calm, especially in the Channel. The Führer has therefore decided to postpone Operation Sea Lion until further notice.”
It is possible that in his mind, Britain could still be brought to terms by blockade and bombing. The war was all but won anyway.
On the same day, British radio intelligence at Bletchley Park decoded a radio signal that authorized the dismantling of loading ramps for parachute troop transports at the airfields in Holland. After careful consideration, it was interpreted as an effect of a larger order to abandon the plan for invasion. This conclusion was relayed to Churchill and Dowding and received with cautious relief.
The RAF fighter units were kept unaware.
In Berlin, a music-hall joke appeared, one of many which made fun of Göring and his weaknesses.
“’Herr Reichsmarschall, if you want to cross the Channel, you’d better use the Moses’ rod. Then you will be able to part the waters of the Channel and allow the Army to march through.’
‘Very well, send someone to fetch it for me. Where is it?’
‘In the British Museum, Herr Reichsmarschall.’”
– Marcel Jullian: The Battle of Britain July-September 1940, Cedric Chivers, 1974
– Matthew Parker: The Battle of Britain July – October 1940, Headline, 2000