The point of DeGaulle's June 18, 1940 speech (https://en.wikipedia.org/wiki/Appeal_of_18_June) was:
(a) Admitting the Germans got the jump on France; (b) conceding that the Germans held the main French territory (France itself); but (c) insisted that the war could be carried on from the many and far flung components of the still extant empire.
A similar comparison would be if the USA was occupied, but patriots still held TX, AK & HI. Would the war be over?
A second and very important point is this: because Hitler had driven out all the Jews, the Nazis never even began preliminary investigations into atomic weapons.
While the US was of course first, both FR & UK were were right behind. While we can't re-write history, without the development of atomic weapons, the Germans were going to be eventually defeated.
For an alternative time-line, what if a nationalist leader had not only *not persecuted the Jews*, but had co-opted them much like our very own neo-cons?
What if all the leading Jewish scientists - like Einstein - had not only stayed, but were active in the war effort? Heck, Germany might have had atomic weapons before 1939.
If so, it would have been game, set & match.
The Germans were close to atomic weapons. It was one of Churchill’s biggest fears. He sent commandos on a series of daring raids aimed at sabotaging Hitler’s nuclear program wherever it was vulnerable to the Allies.
William Stephenson, Churchill’s spymaster, would later say of those raiders: “If it had not been for [the saboteur’s] resolve, the Germans would have had the opportunity to devastate the civilised world. We would be either dead or living under Hitler’s zealots”.
I guess it’s reasonable to say that it’s hard to define “defeat” until there’s a formal ceremony, and obviously DeGaulle didn’t think Petain had any weight to speak for the entire nation so long as a defense could be mounted from...Martinique?! (being coy there...there was always Algeria!).
But I think territorially the Wehrmacht won more then just a tactical skirmish line. Occupying Paris and all the way to the sea in Brittany is pretty convincing.
And saying they were defeated in WWI is certainly stretching it more: that was really a strategic stalemate and nothing more, that was when the French army was still formidable. But being bled white very rapidly...
So I can agree with some criticism of the blanket statement I made, but we can all agree that real defeat would have been permanent had not the real allies - England, America and Russia - been in the fight.
And yes, it was a matter of time before the twin programs of the fission bomb and the bomber to deliver it would have decisively ended the argument. So a view from 30,000 ft would be “they have a lot of ground, but it won’t help them in the end” is reasonable.
Germany is lucky that the 3rd Army punched through into the Rhineland when they did. Had they not, Berlin would have been the first place on the planet to be turned into a radioactive cinder.