Pentagon's "Plan X"

Twenty years ago I read a book on strategy. The author's thesis was that large-scale warfare were going to be a thing of the past, because defensive weaponry was so much cheaper than offensive weapons. A tank can be taken out of service with a guided rocket a 1/50 of its price, same thing for an aircraft.

I think what we are seeing here is a revolution in warfare, like it happened in World War I, when the introduction of the tank brought movement back onto the battlefield.