Best options are probably Thors, missle turrets, photon cannons or void rays. Eventually war will be teenagers sitting at computers moving swarms of autonomous machines on a virtual map, and South Korea will take over the world.
DoD won't appreciate the competition :-)
DoD outsources most a lot of that work. Though, they'd probably prefer a machine gun.
Naming inspiration: Department of Drones
Defending people from drones?
Or using drones to defend people?
(Or both?)
both but more the former
I like the framing you've used there, but mostly military drones are used to "attack" people