I know they've had a few decades of cuddling and trust exercises but does anyone really expect that the Germans and French will hold together in the face of a real threat?
Sure they act friendly these days, but remember these are countries that have sent 100,000s of men to their deaths to gain control of the Alsace. The Alsace! That's pathological behavior.
They are just too different as people to expect any sort of congruence under serious stress.
They'll break apart and regardless of how the threat is resolved they'll spend decades blaming each other for whatever failures there were while claiming for themselves credit for the successes.