An interesting and important distinction between army groups and fronts is that a Soviet front typically had its own army-sized tactical fixed-wing air organization. This air army was directly subordinated to the front commander (typically a ground commander). The reason for that is in the Soviet military doctrine. With the reform of 1935 it was established that in case of a war the peacetime military districts on the border would split upon mobilisation each into a Front Command (taking control of the district's peacetime military formations) and a Military District Command (which stayed behind with the mission to mobilise the reserve formations and put them at the disposal of the Fronts as replacement troops). In that sense the Air Armies were under Air Force command in peacetime, but under the command of the Frontal HQs in wartime and the Fronts were commanded by Ground Forces generals. The entire front might report either to the Stavka or to a theatre of military operations (TVD). A Front was mobilised for a specific operation, after which it could be reformed and tasked with another operation (including a change of the Front's designation) or it could be disbanded with its formations dispersed among the other active Fronts and its HQ reintegrated into its original Military District HQ.