Also, you cannot forget the fact that the colonies were viewed as part of the French empire. Until 1975, you could travel to France without visa, only a passport was necessary. Until the mid 80s, you could take your CFA notes to France, and either use them in some shops in Paris, or exchange them for French Francs, at no cost in any bank. This is how strong the bonds were, and obviously, such divorces are always messy.