So you see the concept of france declaring war on a troubled germany is not so out of the place. Als you must consider the fact that france has #1. a more unified goverment than germany with some left-wing faction like the anarchist and the lowly bolsheviks #2. France has not the colonial territories to worry about so it can rearm itself more effectivly than germany, who has to patrol half of africa and large parts of asia #3. France has a more ideal cause ie. equality, liberty, brotherhood -it is not a conservative royalist dominated country - more opened minded.