The Ukraine war is revolutionizing military technology. Whoever masters it wins.

Because drones fly slowly, produce a lawnmower-like noise and depend on communications links that can be jammed, they are easy to bring down with bullets, missiles or electronic jamming devices. According to the Royal United Services Institute, a British think tank, a quadcopter drone lasts an average of only three flights in combat; a fixed-wing drone, six flights. RUSI estimates that Ukraine has been losing 10,000 drones a month. But unmanned systems are so cheap — they generally cost thousands or tens of thousands of dollars, compared with millions for manned aircraft — that both sides can readily buy or build more of them.