Now hobby-sized drones can fly for up to two hours on solid fuel pellets. Read about it here. This technology isn’t yet commercial, but it probably will be in several years.
I don’t know how far a hobby-sized drone can fly in two hours. And I don’t know how hard it would be to program one to fly from wherever you are to a specific GPS location. But when those two technologies come together, how do you stop a weaponized suicide drone from attacking literally anywhere on Earth?