How aircraft revolutionized warefare, in my opinion, can be summed up in three four parts.
1) Airplanes assured that there would never be another war on such a scale as WW1 where trenchs lined the ground.
2) Power could be projected by transporting men to and from the battle faster, or be used to insert forces, IE; The German paratroop drop on the inpregnable the Belgian Fort Eben Emael. This also, for the most part, makes the defender keep troops back instead of all on frontline duty.
3) The economical and population centers, so crucial to a full scale war effort, are no longer safe and can just as easily be targeted as the frontline soldier.
4) Airplanes could act as artilliary with even more deadly accuracy and vanish just as fast as it appeared.