Ukrainian troops havemade extensive useofdronesKATERYNA KLOCHKO/EPA-EFE/ShutterstockUkraine and Russia are now three years into what has been called the first drone war: not the first in which they were used, but the first in which they have been a major factor on the battlefield. What lessons have others drawn about the shape of future wars?Drones are here to stay, and they will be everywhere on the ground, in the air and at sea in numbers, says Oleksandra Molloy at the University of New South Wales in Canberra, Australia. The point of no return was