Small unmanned aircraft are already transforming warfare, with hand-launched scouts like the Raven and lethal tactical drones like Switchblade already in use by US forces. A bigger revolution is on the way, as swarming software allows a single operator to control large numbers of drones, and smartphone technology means they can be built for $1,000 each -- by anybody, not just governments. This book looks at the history of drone warfare, the rise of big drones like the Predator and how they are being eclipsed by smaller unmanned aircraft. And how the future is being shaped by smartphone technology, swarm software, miniaturised munitions and energy-harvesting that allows small drones to fly forever. It also looks at why current air defence cannot stop the swarms, and what drone swarms will mean for the balance of power and future wars. This is the world of Swarm Troopers