Interesting comments all.
It's obvious that Hitler would have preferred that Britain not resist Germanies incursions on mainland Europe.
The fact that it's widely accepted that Hitler didn't allow the full "might" of the German Army and Luftwaffe to bear on the trapped British at Dunkirk and his many "assertions" that he had no designs on Britain or her Empire would suggest that he would possibly have been amenable to the simple subduing of British forces and a small occupation forces to see that there was no chance of more hostilities (which Britain would have needed US support for, anyway).
This leaves me wondering how serious he really would have been about Operation Lion, had it been possible.
I've have read that the Germans didn't have anywhere near enough landing craft or vessels of the kind needed to transport the necessary equipment.
On the European front, there was comparatively little activity on either side from October '40 until 18 months (9 in the East) later when the US had arrived in Britain in any force. The majority of the action was either in Africa or in the Atlantic. The Atlantic action being solely a result of American aid and supplies being shipped. So given this, the one thing that does puzzle me is the fact that Hitler, having just become bogged down in Russia by the worst winter in memory, decided to declare war on the US at such a time.
I know anyone else had to honour the Tri-partite Pact, but he had never shied from breaking his word or ignoring treaties before. Why support Japan at that time, when things were just beginning to turn bad for him?
