The future warfare is going to be revolutionized by the use of "ultra-lethal" drones.
In 2007, satellite pictures emerged showing new construction at Area 51, the Pentagon's top-secret testing area in the Nevada desert, while two unmanned spy drones are under development now, the New York Post reported.
It has also been revealed that RQ-180, a stealthy spy drone built by Northrop Grumman, is almost ready for combat and it has been designed to fly very high, for a very long time.
Another, recently revealed project is a high-altitude drone SR-72 is being developed by Lockheed Martin that can travel up to six times of the speed of sound and it would be both a spy and strike aircraft, but wouldn't be ready to fly until 2030.
According to Rand Corporation report, terrorist groups might be able to buy small, armed drones and smaller systems could become the next IEDs, low-cost, low-tech weapons that are only of limited lethality individually but attrite significant numbers of US or allied personnel when used in large numbers over time.