What if France surrendered the mainland but evacuated its armed forces to continue the war?
Short answerPreserved French forces could accelerate Italy's defeat, strengthen the Far East, and later help liberate France from the south.
NotesEvacuating ships, aircraft, troops, and useful equipment to Britain or the colonies preserves military power after metropolitan defeat. An Anglo-French-Dutch fleet in the Indian Ocean could delay Japan's war by changing the balance it had to overcome. If Italy also leaves the Axis early, French formations could reorganize in North Africa, cross into Italy, and return through the Alpine frontier. British threats of amphibious landings elsewhere would then force Germany to divide attention between several possible fronts.