The era of drone wars is already upon us. The era of robot wars could be fast approaching.
Already there are unmanned aircraft demonstrators like the arrow-head shaped X-47B that can pretty-well fly a mission by itself with no involvement of a ground-based "pilot".
There are missile systems like the Patriot that can identify and engage targets automatically.
And from here it is not such a jump to a fully-fledged armed robot warrior, a development with huge implications for the way we conduct and even conceive of war-fighting.
On a carpet in a laboratory at the Georgia Institute of Technology in Atlanta, Professor Henrik Christensen's robots are hunting for insurgents. They look like cake-stands on wheels as they scuttle about.
Christensen and his team at Georgia Tech are working on a project funded by the defence company BAE systems.
Their aim is to create unmanned vehicles programmed to map an enemy hideout, allowing human soldiers to get vital information about a building from a safe distance.
"These robots will basically spread out," says Christensen, "they'll go through the environment and map out what it looks like, so that by the time you have humans entering the building you have a lot of intelligence about what's happening there."
The emphasis in this project is reconnaissance and intelligence gathering. But the scientific literature has raised the possibility of armed robots, programmed to behave like locusts or other insects that will swarm together in clouds as enemy targets appear on the battlefield. Each member of the robotic swarm could carry a small warhead or use its kinetic energy to attack a target.