Having a French-administered sector saved the resource-strapped Nazis from having to administer, police and militarily occupy the south. It also meant continuity of French rule and administration over her North African colonies, while all political and economic control was effectively in the hands of the Germans. There was no 'occupied' and 'free' zone as such.

The demarcation line was largely derived from where the German and French armies were standing at the time the armistice was signed. Germany held everything of industrial and military significance, everywhere necessary for operations to attack and defend against the British, conduct naval operations into the Atlantic, and so on.