I remember reading the term in an analysis piece back before 9/1/39. At that time it was used in a theoretical way, of course. I'd hate to have to find it again to back up this assertion. I should have started an index right from the start.
Since the war started I haven't seen World War II or variants used.
I was a little surprised to see "Battle of Britain" come into such common usage as we have seen. From the moment Churchill coined the term - wasn't it at the end of June? - I have been seeing it in news, editorials and anlalysis. The funny thing is, now that it is happening it is not really recognized for what it is. The air war appears to be seen as a symetrical affair. British raids on German occupied areas receive the same sort of coverage as German raids on ships in the Channel or Great Britain. I still haven't noticed any mention of the need for air superiority to enable a German invasion of Britain. Even though that invasion is considered inevitable in the news, if not in the upper reaches of the military and government.
But then I don't read this stuff as carefully as I should. Maybe Baldwin is all over it.
I think more than anything, The Battle of Britain showed Hitler that an invasion of Britain would not be a cakewalk.
And Hitler had bigger fish to fry, The Soviet Union.
He figured at least neutralize Britain enough that he could invade Russia without it becoming a two-front war.
However, Pearl Harbor messed up Hitler’s best-laid plans.