AOR. The acronym AOR stands for a military Area of Responsibility. An AOR is used mostly in a wartime context. It refers to the division of geographic regions in a location. Each region has a specific combatant commander assigned to command and direct operations in that location. The commander is responsible for air, ground and sea missions and support operations, as well as personnel assigned to that particular command. Combatant commanders have authority over all military personnel under their command, regardless of branch of service.