Barrett, the two campaigns started around the same time, both around summer 1940. Germany gave up on Operation Sea Lion in Oct 1940, which was before North Africa campaign was won by the Allies, but it does not take away the fact that the British and Commonwealth men were winning engagements large and small in the Desert War at the same time RAF fighters engaged German aircraft above Britain.
I think the subject line of this thread is more or less a figure of speech, not an exact science. I don't think it can be an exact science as people still can't decide when was the exact starting date of WW2
