Rummaging around in early Churchill, I came across his assertion that the military use of the airplane led to the tank. I hadn't thought about that.
As he explains it, in World War I, the British use of fixed airfields in Belgium made it necessary to defend them against German cavalry raids. This led to the use of Rolls-Royce sedans that had armor affixed to them. Later, armored cars were designed from the ground up. But then the German cavalry dug ditches across roads to impede them. This led to the development of armored vehicles with tracks. "The armoured car was the child of the air; and the Tank its grandchild."
As a general I know says, all warfare is a lethal version of Rock-Paper-Scissors.