Cheap, scaleable and highly autonomous, these weapons are developing quickly – and experts say they should prompt a global rethink about security

On a fine day in early June, Ukrainian soldiers launched their latest killer robot. With a click on a screen, the unattractively named Gogol-M, a fixed-wing aerial drone with a 20-foot wingspan, took off from an undisclosed location and soared into a wide blue sky.

This “mothership” travelled 200km into Russia before releasing two attack drones hanging off its wings. Able to evade radar by flying at a low altitude, the smaller drones autonomously scanned the ground below to find a suitable target, and then locked on for the kill.