unify, unite, merge
Meaning: become one; "Germany unified officially in 1990"; "the cells merge"
mix, mingle, commix, unify, amalgamate
Meaning: to bring or combine together or with something else; "resourcefully he mingled music and dance"
I do not see how this great region is to unify itself without some linguistic compromise--the Germanization of the French-speaking peoples by force is too ridiculous a suggestion to entertain.
Moreover, before Germany can unify to the East she must fight the Russian, and to unify to the West she must fight the French and perhaps the English, and she may have to fight a combination of these powers.