We need cheap defenses to counter cheap attacks.

One end result was described in Neal Stephenson's cyberpunk classic "The Diamond Age." In the not-so-distant future, wars are fought with drones, but the drones have become smaller and smaller and become cheaper and cheaper, to the point where they are microscopic, called nanites or mites and are produced in the trillions. The nanites conduct surveillance, sabotage, and the like.

So a government over a contiguous territory isn't important for waging war anymore, all you need is a large group of people who think the same way you do. Then you send off your nanites to enforce your culture and philosophy on groups you disagree with.

The opposing group is countering with swarms of their own nanites. The nanites do battle, resulting clouds of black soot settling down to the ground as the nanites annihilate each other. Everyday people refer to this as the Toner Wars.

The future is already here. It just isn't well distributed.