I don't know if there are legal differences, but it is true here that the interior minister can only make policy ("water cannons shall be used if people violate paragraph X of law Y"), or give a task to police ("defend the peace of this celebration"), but can't give tactical orders. This is supposed to be a check & balance, so that politicians can't use their powers to apply police violence against opponents.

_{*Lunatic*, n.
One whose delusions are out of fashion.}