A top US general responsible for shaping the military of the future has revealed that robots could make up a quarter of the army within the next few decades. General Robert Cone said last year that the hi-tech machines will fight alongside soldiers on the battlefield by 2030 or 2040, in a bid to make the army'a smaller, more lethal, deployable and agile force'. He said modern health and safety concerns designed to keeping soldiers safe - adding armour and protection to vehicles and personnel - has caused the army to lose some of its lethal edge, but hinted that robots could revitalize its killing force. The US Army has a long-running mission to create autonomous robots - machines capable of making decisions, in real time, on the front line to changing circumstances. More than a decade of war in Afghanistan and Iraq has allowed the public to see the huge resources already dedicated to unmanned systems; from the high-flying Global Hawk to the lethal Predator drones to hand-launched Raven.