From my understanding of the Franco-Prussian War, Germany was worried about causing a bitter France along its borders after Paris fell. However, that did not turn out so well as France became so revenge minded.
In WW1, Germany famously attacked France in an attempt to secure its western front. The Septemberprogramm that was debated for a German victory would have crushed France and essentially have turned it into a vassal. I would think that after the swift victory of Germany in the Franco-Prussian War, they could have placed in stricter terms beyond some land and reparations.
If so, what would Germany have demanded? Could they have the ability to install a puppet government in France, especially after the chaos caused by the Paris Commune? Could they have placed terms harsh enough to prevent France from rebuilding its army or destroying fortresses near the German border? Obtained ports?
(People want safety for their children above all else -- the trade-off of security under a welcomed occupation and a supply of food trumps national autonomy.)